/*
** This routine is callback for sqlite3WalkExpr().
**
** Resolve symbolic names into TK_COLUMN operators for the current
** node in the expression tree. Return 0 to continue the search down
** the tree or 2 to abort the tree walk.
**
** This routine also does error checking and name resolution for
** function names. The operator for aggregate functions is changed
** to TK_AGG_FUNCTION.
*/
static int resolveExprStep(Walker *pWalker, Expr *pExpr){
NameContext *pNC;
Parse *pParse;
pNC = pWalker->u.pNC;
assert( pNC!=0 );
pParse = pNC->pParse;
assert( pParse==pWalker->pParse );
if( ExprHasAnyProperty(pExpr, EP_Resolved) ) return WRC_Prune;
ExprSetProperty(pExpr, EP_Resolved);
#ifndef NDEBUG
if( pNC->pSrcList && pNC->pSrcList->nAlloc>0 ){
SrcList *pSrcList = pNC->pSrcList;
int i;
for(i=0; i<pNC->pSrcList->nSrc; i++){
assert( pSrcList->a[i].iCursor>=0 && pSrcList->a[i].iCursor<pParse->nTab);
}
}
#endif
switch( pExpr->op ){
#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
/* The special operator TK_ROW means use the rowid for the first
** column in the FROM clause. This is used by the LIMIT and ORDER BY
** clause processing on UPDATE and DELETE statements.
*/
case TK_ROW: {
SrcList *pSrcList = pNC->pSrcList;
struct SrcList_item *pItem;
assert( pSrcList && pSrcList->nSrc==1 );
pItem = pSrcList->a;
pExpr->op = TK_COLUMN;
pExpr->pTab = pItem->pTab;
pExpr->iTable = pItem->iCursor;
pExpr->iColumn = -1;
pExpr->affinity = SQLITE_AFF_INTEGER;
break;
}
#endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY) */
/* A lone identifier is the name of a column.
*/
case TK_ID: {
return lookupName(pParse, 0, 0, pExpr->u.zToken, pNC, pExpr);
}
/* A table name and column name: ID.ID
** Or a database, table and column: ID.ID.ID
*/
case TK_DOT: {
const char *zColumn;
const char *zTable;
const char *zDb;
Expr *pRight;
/* if( pSrcList==0 ) break; */
pRight = pExpr->pRight;
if( pRight->op==TK_ID ){
zDb = 0;
zTable = pExpr->pLeft->u.zToken;
zColumn = pRight->u.zToken;
}else{
assert( pRight->op==TK_DOT );
zDb = pExpr->pLeft->u.zToken;
zTable = pRight->pLeft->u.zToken;
zColumn = pRight->pRight->u.zToken;
}
return lookupName(pParse, zDb, zTable, zColumn, pNC, pExpr);
}
/* Resolve function names
*/
case TK_CONST_FUNC:
case TK_FUNCTION: {
ExprList *pList = pExpr->x.pList; /* The argument list */
int n = pList ? pList->nExpr : 0; /* Number of arguments */
int no_such_func = 0; /* True if no such function exists */
int wrong_num_args = 0; /* True if wrong number of arguments */
int is_agg = 0; /* True if is an aggregate function */
int auth; /* Authorization to use the function */
int nId; /* Number of characters in function name */
const char *zId; /* The function name. */
FuncDef *pDef; /* Information about the function */
u8 enc = ENC(pParse->db); /* The database encoding */
testcase( pExpr->op==TK_CONST_FUNC );
assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
zId = pExpr->u.zToken;
nId = sqlite3Strlen30(zId);
pDef = sqlite3FindFunction(pParse->db, zId, nId, n, enc, 0);
if( pDef==0 ){
pDef = sqlite3FindFunction(pParse->db, zId, nId, -2, enc, 0);
if( pDef==0 ){
no_such_func = 1;
}else{
wrong_num_args = 1;
}
}else{
is_agg = pDef->xFunc==0;
}
#ifndef SQLITE_OMIT_AUTHORIZATION
if( pDef ){
auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0, pDef->zName, 0);
if( auth!=SQLITE_OK ){
if( auth==SQLITE_DENY ){
sqlite3ErrorMsg(pParse, "not authorized to use function: %s",
pDef->zName);
pNC->nErr++;
}
pExpr->op = TK_NULL;
return WRC_Prune;
}
}
#endif
if( is_agg && (pNC->ncFlags & NC_AllowAgg)==0 ){
sqlite3ErrorMsg(pParse, "misuse of aggregate function %.*s()", nId,zId);
pNC->nErr++;
is_agg = 0;
}else if( no_such_func ){
sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId);
pNC->nErr++;
}else if( wrong_num_args ){
sqlite3ErrorMsg(pParse,"wrong number of arguments to function %.*s()",
nId, zId);
pNC->nErr++;
}
if( is_agg ) pNC->ncFlags &= ~NC_AllowAgg;
sqlite3WalkExprList(pWalker, pList);
if( is_agg ){
NameContext *pNC2 = pNC;
pExpr->op = TK_AGG_FUNCTION;
pExpr->op2 = 0;
while( pNC2 && !sqlite3FunctionUsesThisSrc(pExpr, pNC2->pSrcList) ){
pExpr->op2++;
pNC2 = pNC2->pNext;
}
if( pNC2 ) pNC2->ncFlags |= NC_HasAgg;
pNC->ncFlags |= NC_AllowAgg;
}
/* FIX ME: Compute pExpr->affinity based on the expected return
** type of the function
*/
return WRC_Prune;
}
#ifndef SQLITE_OMIT_SUBQUERY
case TK_SELECT:
case TK_EXISTS: testcase( pExpr->op==TK_EXISTS );
#endif
case TK_IN: {
testcase( pExpr->op==TK_IN );
if( ExprHasProperty(pExpr, EP_xIsSelect) ){
int nRef = pNC->nRef;
#ifndef SQLITE_OMIT_CHECK
if( (pNC->ncFlags & NC_IsCheck)!=0 ){
sqlite3ErrorMsg(pParse,"subqueries prohibited in CHECK constraints");
}
#endif
sqlite3WalkSelect(pWalker, pExpr->x.pSelect);
assert( pNC->nRef>=nRef );
if( nRef!=pNC->nRef ){
ExprSetProperty(pExpr, EP_VarSelect);
}
}
break;
}
#ifndef SQLITE_OMIT_CHECK
case TK_VARIABLE: {
if( (pNC->ncFlags & NC_IsCheck)!=0 ){
sqlite3ErrorMsg(pParse,"parameters prohibited in CHECK constraints");
}
break;
}
#endif
}
return (pParse->nErr || pParse->db->mallocFailed) ? WRC_Abort : WRC_Continue;
}
/*
** This is called by the parser when it sees a CREATE TRIGGER statement
** up to the point of the BEGIN before the trigger actions. A Trigger
** structure is generated based on the information available and stored
** in pParse->pNewTrigger. After the trigger actions have been parsed, the
** sqlite3FinishTrigger() function is called to complete the trigger
** construction process.
*/
void sqlite3BeginTrigger(
Parse *pParse, /* The parse context of the CREATE TRIGGER statement */
Token *pName1, /* The name of the trigger */
Token *pName2, /* The name of the trigger */
int tr_tm, /* One of TK_BEFORE, TK_AFTER, TK_INSTEAD */
int op, /* One of TK_INSERT, TK_UPDATE, TK_DELETE */
IdList *pColumns, /* column list if this is an UPDATE OF trigger */
SrcList *pTableName,/* The name of the table/view the trigger applies to */
int foreach, /* One of TK_ROW or TK_STATEMENT */
Expr *pWhen, /* WHEN clause */
int isTemp /* True if the TEMPORARY keyword is present */
){
Trigger *pTrigger = 0;
Table *pTab;
char *zName = 0; /* Name of the trigger */
sqlite3 *db = pParse->db;
int iDb; /* The database to store the trigger in */
Token *pName; /* The unqualified db name */
DbFixer sFix;
if( isTemp ){
/* If TEMP was specified, then the trigger name may not be qualified. */
if( pName2 && pName2->n>0 ){
sqlite3ErrorMsg(pParse, "temporary trigger may not have qualified name");
goto trigger_cleanup;
}
iDb = 1;
pName = pName1;
}else{
/* Figure out the db that the the trigger will be created in */
iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
if( iDb<0 ){
goto trigger_cleanup;
}
}
/* If the trigger name was unqualified, and the table is a temp table,
** then set iDb to 1 to create the trigger in the temporary database.
** If sqlite3SrcListLookup() returns 0, indicating the table does not
** exist, the error is caught by the block below.
*/
if( !pTableName || sqlite3_malloc_failed ) goto trigger_cleanup;
pTab = sqlite3SrcListLookup(pParse, pTableName);
if( pName2->n==0 && pTab && pTab->iDb==1 ){
iDb = 1;
}
/* Ensure the table name matches database name and that the table exists */
if( sqlite3_malloc_failed ) goto trigger_cleanup;
assert( pTableName->nSrc==1 );
if( sqlite3FixInit(&sFix, pParse, iDb, "trigger", pName) &&
sqlite3FixSrcList(&sFix, pTableName) ){
goto trigger_cleanup;
}
pTab = sqlite3SrcListLookup(pParse, pTableName);
if( !pTab ){
/* The table does not exist. */
goto trigger_cleanup;
}
/* Check that the trigger name is not reserved and that no trigger of the
** specified name exists */
zName = sqlite3NameFromToken(pName);
if( !zName || SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
goto trigger_cleanup;
}
if( sqlite3HashFind(&(db->aDb[iDb].trigHash), zName,pName->n+1) ){
sqlite3ErrorMsg(pParse, "trigger %T already exists", pName);
goto trigger_cleanup;
}
/* Do not create a trigger on a system table */
if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 ){
sqlite3ErrorMsg(pParse, "cannot create trigger on system table");
pParse->nErr++;
goto trigger_cleanup;
}
/* INSTEAD of triggers are only for views and views only support INSTEAD
** of triggers.
*/
if( pTab->pSelect && tr_tm!=TK_INSTEAD ){
sqlite3ErrorMsg(pParse, "cannot create %s trigger on view: %S",
(tr_tm == TK_BEFORE)?"BEFORE":"AFTER", pTableName, 0);
goto trigger_cleanup;
}
if( !pTab->pSelect && tr_tm==TK_INSTEAD ){
sqlite3ErrorMsg(pParse, "cannot create INSTEAD OF"
" trigger on table: %S", pTableName, 0);
goto trigger_cleanup;
}
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int code = SQLITE_CREATE_TRIGGER;
const char *zDb = db->aDb[pTab->iDb].zName;
const char *zDbTrig = isTemp ? db->aDb[1].zName : zDb;
if( pTab->iDb==1 || isTemp ) code = SQLITE_CREATE_TEMP_TRIGGER;
if( sqlite3AuthCheck(pParse, code, zName, pTab->zName, zDbTrig) ){
goto trigger_cleanup;
}
if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(pTab->iDb),0,zDb)){
goto trigger_cleanup;
}
}
#endif
/* INSTEAD OF triggers can only appear on views and BEFORE triggers
** cannot appear on views. So we might as well translate every
** INSTEAD OF trigger into a BEFORE trigger. It simplifies code
** elsewhere.
*/
if (tr_tm == TK_INSTEAD){
tr_tm = TK_BEFORE;
}
/* Build the Trigger object */
pTrigger = (Trigger*)sqliteMalloc(sizeof(Trigger));
if( pTrigger==0 ) goto trigger_cleanup;
pTrigger->name = zName;
zName = 0;
pTrigger->table = sqliteStrDup(pTableName->a[0].zName);
pTrigger->iDb = iDb;
pTrigger->iTabDb = pTab->iDb;
pTrigger->op = op;
pTrigger->tr_tm = tr_tm==TK_BEFORE ? TRIGGER_BEFORE : TRIGGER_AFTER;
pTrigger->pWhen = sqlite3ExprDup(pWhen);
pTrigger->pColumns = sqlite3IdListDup(pColumns);
pTrigger->foreach = foreach;
sqlite3TokenCopy(&pTrigger->nameToken,pName);
assert( pParse->pNewTrigger==0 );
pParse->pNewTrigger = pTrigger;
trigger_cleanup:
sqliteFree(zName);
sqlite3SrcListDelete(pTableName);
sqlite3IdListDelete(pColumns);
sqlite3ExprDelete(pWhen);
if( !pParse->pNewTrigger ){
sqlite3DeleteTrigger(pTrigger);
}else{
assert( pParse->pNewTrigger==pTrigger );
}
}
/*
** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up
** that name in the set of source tables in pSrcList and make the pExpr
** expression node refer back to that source column. The following changes
** are made to pExpr:
**
** pExpr->iDb Set the index in db->aDb[] of the database X
** (even if X is implied).
** pExpr->iTable Set to the cursor number for the table obtained
** from pSrcList.
** pExpr->pTab Points to the Table structure of X.Y (even if
** X and/or Y are implied.)
** pExpr->iColumn Set to the column number within the table.
** pExpr->op Set to TK_COLUMN.
** pExpr->pLeft Any expression this points to is deleted
** pExpr->pRight Any expression this points to is deleted.
**
** The zDb variable is the name of the database (the "X"). This value may be
** NULL meaning that name is of the form Y.Z or Z. Any available database
** can be used. The zTable variable is the name of the table (the "Y"). This
** value can be NULL if zDb is also NULL. If zTable is NULL it
** means that the form of the name is Z and that columns from any table
** can be used.
**
** If the name cannot be resolved unambiguously, leave an error message
** in pParse and return WRC_Abort. Return WRC_Prune on success.
*/
static int lookupName(
Parse *pParse, /* The parsing context */
const char *zDb, /* Name of the database containing table, or NULL */
const char *zTab, /* Name of table containing column, or NULL */
const char *zCol, /* Name of the column. */
NameContext *pNC, /* The name context used to resolve the name */
Expr *pExpr /* Make this EXPR node point to the selected column */
){
int i, j; /* Loop counters */
int cnt = 0; /* Number of matching column names */
int cntTab = 0; /* Number of matching table names */
int nSubquery = 0; /* How many levels of subquery */
sqlite3 *db = pParse->db; /* The database connection */
struct SrcList_item *pItem; /* Use for looping over pSrcList items */
struct SrcList_item *pMatch = 0; /* The matching pSrcList item */
NameContext *pTopNC = pNC; /* First namecontext in the list */
Schema *pSchema = 0; /* Schema of the expression */
int isTrigger = 0;
assert( pNC ); /* the name context cannot be NULL. */
assert( zCol ); /* The Z in X.Y.Z cannot be NULL */
assert( !ExprHasAnyProperty(pExpr, EP_TokenOnly|EP_Reduced) );
/* Initialize the node to no-match */
pExpr->iTable = -1;
pExpr->pTab = 0;
ExprSetIrreducible(pExpr);
/* Start at the inner-most context and move outward until a match is found */
while( pNC && cnt==0 ){
ExprList *pEList;
SrcList *pSrcList = pNC->pSrcList;
if( pSrcList ){
for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){
Table *pTab;
int iDb;
Column *pCol;
pTab = pItem->pTab;
assert( pTab!=0 && pTab->zName!=0 );
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
assert( pTab->nCol>0 );
if( zTab ){
if( pItem->zAlias ){
char *zTabName = pItem->zAlias;
if( sqlite3StrICmp(zTabName, zTab)!=0 ) continue;
}else{
char *zTabName = pTab->zName;
if( NEVER(zTabName==0) || sqlite3StrICmp(zTabName, zTab)!=0 ){
continue;
}
if( zDb!=0 && sqlite3StrICmp(db->aDb[iDb].zName, zDb)!=0 ){
continue;
}
}
}
if( 0==(cntTab++) ){
pExpr->iTable = pItem->iCursor;
pExpr->pTab = pTab;
pSchema = pTab->pSchema;
pMatch = pItem;
}
for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){
if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
/* If there has been exactly one prior match and this match
** is for the right-hand table of a NATURAL JOIN or is in a
** USING clause, then skip this match.
*/
if( cnt==1 ){
if( pItem->jointype & JT_NATURAL ) continue;
if( nameInUsingClause(pItem->pUsing, zCol) ) continue;
}
cnt++;
pExpr->iTable = pItem->iCursor;
pExpr->pTab = pTab;
pMatch = pItem;
pSchema = pTab->pSchema;
/* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */
pExpr->iColumn = j==pTab->iPKey ? -1 : (i16)j;
break;
}
}
}
}
#ifndef SQLITE_OMIT_TRIGGER
/* If we have not already resolved the name, then maybe
** it is a new.* or old.* trigger argument reference
*/
if( zDb==0 && zTab!=0 && cnt==0 && pParse->pTriggerTab!=0 ){
int op = pParse->eTriggerOp;
Table *pTab = 0;
assert( op==TK_DELETE || op==TK_UPDATE || op==TK_INSERT );
if( op!=TK_DELETE && sqlite3StrICmp("new",zTab) == 0 ){
pExpr->iTable = 1;
pTab = pParse->pTriggerTab;
}else if( op!=TK_INSERT && sqlite3StrICmp("old",zTab)==0 ){
pExpr->iTable = 0;
pTab = pParse->pTriggerTab;
}
if( pTab ){
int iCol;
pSchema = pTab->pSchema;
cntTab++;
for(iCol=0; iCol<pTab->nCol; iCol++){
Column *pCol = &pTab->aCol[iCol];
if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
if( iCol==pTab->iPKey ){
iCol = -1;
}
break;
}
}
if( iCol>=pTab->nCol && sqlite3IsRowid(zCol) ){
iCol = -1; /* IMP: R-44911-55124 */
}
if( iCol<pTab->nCol ){
cnt++;
if( iCol<0 ){
pExpr->affinity = SQLITE_AFF_INTEGER;
}else if( pExpr->iTable==0 ){
testcase( iCol==31 );
testcase( iCol==32 );
pParse->oldmask |= (iCol>=32 ? 0xffffffff : (((u32)1)<<iCol));
}else{
testcase( iCol==31 );
testcase( iCol==32 );
pParse->newmask |= (iCol>=32 ? 0xffffffff : (((u32)1)<<iCol));
}
pExpr->iColumn = (i16)iCol;
pExpr->pTab = pTab;
isTrigger = 1;
}
}
}
#endif /* !defined(SQLITE_OMIT_TRIGGER) */
/*
** Perhaps the name is a reference to the ROWID
*/
if( cnt==0 && cntTab==1 && sqlite3IsRowid(zCol) ){
cnt = 1;
pExpr->iColumn = -1; /* IMP: R-44911-55124 */
pExpr->affinity = SQLITE_AFF_INTEGER;
}
/*
** If the input is of the form Z (not Y.Z or X.Y.Z) then the name Z
** might refer to an result-set alias. This happens, for example, when
** we are resolving names in the WHERE clause of the following command:
**
** SELECT a+b AS x FROM table WHERE x<10;
**
** In cases like this, replace pExpr with a copy of the expression that
** forms the result set entry ("a+b" in the example) and return immediately.
** Note that the expression in the result set should have already been
** resolved by the time the WHERE clause is resolved.
*/
if( cnt==0 && (pEList = pNC->pEList)!=0 && zTab==0 ){
for(j=0; j<pEList->nExpr; j++){
char *zAs = pEList->a[j].zName;
if( zAs!=0 && sqlite3StrICmp(zAs, zCol)==0 ){
Expr *pOrig;
assert( pExpr->pLeft==0 && pExpr->pRight==0 );
assert( pExpr->x.pList==0 );
assert( pExpr->x.pSelect==0 );
pOrig = pEList->a[j].pExpr;
if( (pNC->ncFlags&NC_AllowAgg)==0 && ExprHasProperty(pOrig, EP_Agg) ){
sqlite3ErrorMsg(pParse, "misuse of aliased aggregate %s", zAs);
return WRC_Abort;
}
resolveAlias(pParse, pEList, j, pExpr, "", nSubquery);
cnt = 1;
pMatch = 0;
assert( zTab==0 && zDb==0 );
goto lookupname_end;
}
}
}
/* Advance to the next name context. The loop will exit when either
** we have a match (cnt>0) or when we run out of name contexts.
*/
if( cnt==0 ){
pNC = pNC->pNext;
nSubquery++;
}
}
/*
** If X and Y are NULL (in other words if only the column name Z is
** supplied) and the value of Z is enclosed in double-quotes, then
** Z is a string literal if it doesn't match any column names. In that
** case, we need to return right away and not make any changes to
** pExpr.
**
** Because no reference was made to outer contexts, the pNC->nRef
** fields are not changed in any context.
*/
if( cnt==0 && zTab==0 && ExprHasProperty(pExpr,EP_DblQuoted) ){
pExpr->op = TK_STRING;
pExpr->pTab = 0;
return WRC_Prune;
}
/*
** cnt==0 means there was not match. cnt>1 means there were two or
** more matches. Either way, we have an error.
*/
if( cnt!=1 ){
const char *zErr;
zErr = cnt==0 ? "no such column" : "ambiguous column name";
if( zDb ){
sqlite3ErrorMsg(pParse, "%s: %s.%s.%s", zErr, zDb, zTab, zCol);
}else if( zTab ){
sqlite3ErrorMsg(pParse, "%s: %s.%s", zErr, zTab, zCol);
}else{
sqlite3ErrorMsg(pParse, "%s: %s", zErr, zCol);
}
pParse->checkSchema = 1;
pTopNC->nErr++;
}
/* If a column from a table in pSrcList is referenced, then record
** this fact in the pSrcList.a[].colUsed bitmask. Column 0 causes
** bit 0 to be set. Column 1 sets bit 1. And so forth. If the
** column number is greater than the number of bits in the bitmask
** then set the high-order bit of the bitmask.
*/
if( pExpr->iColumn>=0 && pMatch!=0 ){
int n = pExpr->iColumn;
testcase( n==BMS-1 );
if( n>=BMS ){
n = BMS-1;
}
assert( pMatch->iCursor==pExpr->iTable );
pMatch->colUsed |= ((Bitmask)1)<<n;
}
/* Clean up and return
*/
sqlite3ExprDelete(db, pExpr->pLeft);
pExpr->pLeft = 0;
sqlite3ExprDelete(db, pExpr->pRight);
pExpr->pRight = 0;
pExpr->op = (isTrigger ? TK_TRIGGER : TK_COLUMN);
lookupname_end:
if( cnt==1 ){
assert( pNC!=0 );
sqlite3AuthRead(pParse, pExpr, pSchema, pNC->pSrcList);
/* Increment the nRef value on all name contexts from TopNC up to
** the point where the name matched. */
for(;;){
assert( pTopNC!=0 );
pTopNC->nRef++;
if( pTopNC==pNC ) break;
pTopNC = pTopNC->pNext;
}
return WRC_Prune;
} else {
return WRC_Abort;
}
}
/*
** This routine is called by the parser to process an ATTACH statement:
**
** ATTACH DATABASE filename AS dbname
**
** The pFilename and pDbname arguments are the tokens that define the
** filename and dbname in the ATTACH statement.
*/
void sqlite3Attach(
Parse *pParse, /* The parser context */
Token *pFilename, /* Name of database file */
Token *pDbname, /* Name of the database to use internally */
int keyType, /* 0: no key. 1: TEXT, 2: BLOB */
Token *pKey /* Text of the key for keytype 1 and 2 */
){
Db *aNew;
int rc, i;
char *zFile = 0;
char *zName = 0;
sqlite3 *db;
Vdbe *v;
v = sqlite3GetVdbe(pParse);
if( !v ) return;
sqlite3VdbeAddOp(v, OP_Expire, 1, 0);
sqlite3VdbeAddOp(v, OP_Halt, 0, 0);
if( pParse->explain ) return;
db = pParse->db;
if( db->nDb>=MAX_ATTACHED+2 ){
sqlite3ErrorMsg(pParse, "too many attached databases - max %d",
MAX_ATTACHED);
pParse->rc = SQLITE_ERROR;
return;
}
if( !db->autoCommit ){
sqlite3ErrorMsg(pParse, "cannot ATTACH database within transaction");
pParse->rc = SQLITE_ERROR;
return;
}
zFile = sqlite3NameFromToken(pFilename);
if( zFile==0 ){
goto attach_end;
}
#ifndef SQLITE_OMIT_AUTHORIZATION
if( sqlite3AuthCheck(pParse, SQLITE_ATTACH, zFile, 0, 0)!=SQLITE_OK ){
goto attach_end;
}
#endif /* SQLITE_OMIT_AUTHORIZATION */
zName = sqlite3NameFromToken(pDbname);
if( zName==0 ){
goto attach_end;
}
for(i=0; i<db->nDb; i++){
char *z = db->aDb[i].zName;
if( z && sqlite3StrICmp(z, zName)==0 ){
sqlite3ErrorMsg(pParse, "database %s is already in use", zName);
pParse->rc = SQLITE_ERROR;
goto attach_end;
}
}
if( db->aDb==db->aDbStatic ){
aNew = sqliteMalloc( sizeof(db->aDb[0])*3 );
if( aNew==0 ){
goto attach_end;
}
memcpy(aNew, db->aDb, sizeof(db->aDb[0])*2);
}else{
aNew = sqliteRealloc(db->aDb, sizeof(db->aDb[0])*(db->nDb+1) );
if( aNew==0 ){
goto attach_end;
}
}
db->aDb = aNew;
aNew = &db->aDb[db->nDb++];
memset(aNew, 0, sizeof(*aNew));
sqlite3HashInit(&aNew->tblHash, SQLITE_HASH_STRING, 0);
sqlite3HashInit(&aNew->idxHash, SQLITE_HASH_STRING, 0);
sqlite3HashInit(&aNew->trigHash, SQLITE_HASH_STRING, 0);
sqlite3HashInit(&aNew->aFKey, SQLITE_HASH_STRING, 1);
aNew->zName = zName;
zName = 0;
aNew->safety_level = 3;
rc = sqlite3BtreeFactory(db, zFile, 0, MAX_PAGES, &aNew->pBt);
if( rc ){
sqlite3ErrorMsg(pParse, "unable to open database: %s", zFile);
}
#if SQLITE_HAS_CODEC
{
extern int sqlite3CodecAttach(sqlite3*, int, void*, int);
char *zKey;
int nKey;
if( keyType==0 ){
/* No key specified. Use the key from the main database */
extern void sqlite3CodecGetKey(sqlite3*, int, void**, int*);
sqlite3CodecGetKey(db, 0, (void**)&zKey, &nKey);
}else if( keyType==1 ){
/* Key specified as text */
zKey = sqlite3NameFromToken(pKey);
nKey = strlen(zKey);
}else{
/* Key specified as a BLOB */
char *zTemp;
assert( keyType==2 );
pKey->z++;
pKey->n--;
zTemp = sqlite3NameFromToken(pKey);
zKey = sqlite3HexToBlob(zTemp);
sqliteFree(zTemp);
}
sqlite3CodecAttach(db, db->nDb-1, zKey, nKey);
if( keyType ){
sqliteFree(zKey);
}
}
#endif
db->flags &= ~SQLITE_Initialized;
if( pParse->nErr==0 && rc==SQLITE_OK ){
rc = sqlite3ReadSchema(pParse);
}
if( rc ){
int i = db->nDb - 1;
assert( i>=2 );
if( db->aDb[i].pBt ){
sqlite3BtreeClose(db->aDb[i].pBt);
db->aDb[i].pBt = 0;
}
sqlite3ResetInternalSchema(db, 0);
if( 0==pParse->nErr ){
pParse->nErr++;
pParse->rc = SQLITE_ERROR;
}
}
attach_end:
sqliteFree(zFile);
sqliteFree(zName);
}
/*
** Write an error message into pParse->zErrMsg that explains that the
** user-supplied authorization function returned an illegal value.
*/
static void sqliteAuthBadReturnCode(Parse *pParse){
sqlite3ErrorMsg(pParse, "authorizer malfunction");
pParse->rc = SQLITE_ERROR;
}
/*
** Process an UPDATE statement.
**
** UPDATE OR IGNORE table_wxyz SET a=b, c=d WHERE e<5 AND f NOT NULL;
** \_______/ \________/ \______/ \________________/
* onError pTabList pChanges pWhere
*/
void sqlite3Update(
Parse *pParse, /* The parser context */
SrcList *pTabList, /* The table in which we should change things */
ExprList *pChanges, /* Things to be changed */
Expr *pWhere, /* The WHERE clause. May be null */
int onError, /* How to handle constraint errors */
ExprList *pOrderBy, /* ORDER BY clause. May be null */
Expr *pLimit, /* LIMIT clause. May be null */
Upsert *pUpsert /* ON CONFLICT clause, or null */
){
int i, j; /* Loop counters */
Table *pTab; /* The table to be updated */
int addrTop = 0; /* VDBE instruction address of the start of the loop */
WhereInfo *pWInfo; /* Information about the WHERE clause */
Vdbe *v; /* The virtual database engine */
Index *pIdx; /* For looping over indices */
Index *pPk; /* The PRIMARY KEY index for WITHOUT ROWID tables */
int nIdx; /* Number of indices that need updating */
int iBaseCur; /* Base cursor number */
int iDataCur; /* Cursor for the canonical data btree */
int iIdxCur; /* Cursor for the first index */
sqlite3 *db; /* The database structure */
int *aRegIdx = 0; /* First register in array assigned to each index */
int *aXRef = 0; /* aXRef[i] is the index in pChanges->a[] of the
** an expression for the i-th column of the table.
** aXRef[i]==-1 if the i-th column is not changed. */
u8 *aToOpen; /* 1 for tables and indices to be opened */
u8 chngPk; /* PRIMARY KEY changed in a WITHOUT ROWID table */
u8 chngRowid; /* Rowid changed in a normal table */
u8 chngKey; /* Either chngPk or chngRowid */
Expr *pRowidExpr = 0; /* Expression defining the new record number */
AuthContext sContext; /* The authorization context */
NameContext sNC; /* The name-context to resolve expressions in */
int iDb; /* Database containing the table being updated */
int eOnePass; /* ONEPASS_XXX value from where.c */
int hasFK; /* True if foreign key processing is required */
int labelBreak; /* Jump here to break out of UPDATE loop */
int labelContinue; /* Jump here to continue next step of UPDATE loop */
int flags; /* Flags for sqlite3WhereBegin() */
#ifndef SQLITE_OMIT_TRIGGER
int isView; /* True when updating a view (INSTEAD OF trigger) */
Trigger *pTrigger; /* List of triggers on pTab, if required */
int tmask; /* Mask of TRIGGER_BEFORE|TRIGGER_AFTER */
#endif
int newmask; /* Mask of NEW.* columns accessed by BEFORE triggers */
int iEph = 0; /* Ephemeral table holding all primary key values */
int nKey = 0; /* Number of elements in regKey for WITHOUT ROWID */
int aiCurOnePass[2]; /* The write cursors opened by WHERE_ONEPASS */
int addrOpen = 0; /* Address of OP_OpenEphemeral */
int iPk = 0; /* First of nPk cells holding PRIMARY KEY value */
i16 nPk = 0; /* Number of components of the PRIMARY KEY */
int bReplace = 0; /* True if REPLACE conflict resolution might happen */
/* Register Allocations */
int regRowCount = 0; /* A count of rows changed */
int regOldRowid = 0; /* The old rowid */
int regNewRowid = 0; /* The new rowid */
int regNew = 0; /* Content of the NEW.* table in triggers */
int regOld = 0; /* Content of OLD.* table in triggers */
int regRowSet = 0; /* Rowset of rows to be updated */
int regKey = 0; /* composite PRIMARY KEY value */
memset(&sContext, 0, sizeof(sContext));
db = pParse->db;
if( pParse->nErr || db->mallocFailed ){
goto update_cleanup;
}
assert( pTabList->nSrc==1 );
/* Locate the table which we want to update.
*/
pTab = sqlite3SrcListLookup(pParse, pTabList);
if( pTab==0 ) goto update_cleanup;
iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
/* Figure out if we have any triggers and if the table being
** updated is a view.
*/
#ifndef SQLITE_OMIT_TRIGGER
pTrigger = sqlite3TriggersExist(pParse, pTab, TK_UPDATE, pChanges, &tmask);
isView = pTab->pSelect!=0;
assert( pTrigger || tmask==0 );
#else
# define pTrigger 0
# define isView 0
# define tmask 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif
#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
if( !isView ){
pWhere = sqlite3LimitWhere(
pParse, pTabList, pWhere, pOrderBy, pLimit, "UPDATE"
);
pOrderBy = 0;
pLimit = 0;
}
#endif
if( sqlite3ViewGetColumnNames(pParse, pTab) ){
goto update_cleanup;
}
if( sqlite3IsReadOnly(pParse, pTab, tmask) ){
goto update_cleanup;
}
/* Allocate a cursors for the main database table and for all indices.
** The index cursors might not be used, but if they are used they
** need to occur right after the database cursor. So go ahead and
** allocate enough space, just in case.
*/
iBaseCur = iDataCur = pParse->nTab++;
iIdxCur = iDataCur+1;
pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);
testcase( pPk!=0 && pPk!=pTab->pIndex );
for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){
if( pPk==pIdx ){
iDataCur = pParse->nTab;
}
pParse->nTab++;
}
if( pUpsert ){
/* On an UPSERT, reuse the same cursors already opened by INSERT */
iDataCur = pUpsert->iDataCur;
iIdxCur = pUpsert->iIdxCur;
pParse->nTab = iBaseCur;
}
pTabList->a[0].iCursor = iDataCur;
/* Allocate space for aXRef[], aRegIdx[], and aToOpen[].
** Initialize aXRef[] and aToOpen[] to their default values.
*/
aXRef = sqlite3DbMallocRawNN(db, sizeof(int) * (pTab->nCol+nIdx) + nIdx+2 );
if( aXRef==0 ) goto update_cleanup;
aRegIdx = aXRef+pTab->nCol;
aToOpen = (u8*)(aRegIdx+nIdx);
memset(aToOpen, 1, nIdx+1);
aToOpen[nIdx+1] = 0;
for(i=0; i<pTab->nCol; i++) aXRef[i] = -1;
/* Initialize the name-context */
memset(&sNC, 0, sizeof(sNC));
sNC.pParse = pParse;
sNC.pSrcList = pTabList;
sNC.uNC.pUpsert = pUpsert;
sNC.ncFlags = NC_UUpsert;
/* Resolve the column names in all the expressions of the
** of the UPDATE statement. Also find the column index
** for each column to be updated in the pChanges array. For each
** column to be updated, make sure we have authorization to change
** that column.
*/
chngRowid = chngPk = 0;
for(i=0; i<pChanges->nExpr; i++){
if( sqlite3ResolveExprNames(&sNC, pChanges->a[i].pExpr) ){
goto update_cleanup;
}
for(j=0; j<pTab->nCol; j++){
if( sqlite3StrICmp(pTab->aCol[j].zName, pChanges->a[i].zName)==0 ){
if( j==pTab->iPKey ){
chngRowid = 1;
pRowidExpr = pChanges->a[i].pExpr;
}else if( pPk && (pTab->aCol[j].colFlags & COLFLAG_PRIMKEY)!=0 ){
chngPk = 1;
}
aXRef[j] = i;
break;
}
}
if( j>=pTab->nCol ){
if( pPk==0 && sqlite3IsRowid(pChanges->a[i].zName) ){
j = -1;
chngRowid = 1;
pRowidExpr = pChanges->a[i].pExpr;
}else{
sqlite3ErrorMsg(pParse, "no such column: %s", pChanges->a[i].zName);
pParse->checkSchema = 1;
goto update_cleanup;
}
}
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int rc;
rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName,
j<0 ? "ROWID" : pTab->aCol[j].zName,
db->aDb[iDb].zDbSName);
if( rc==SQLITE_DENY ){
goto update_cleanup;
}else if( rc==SQLITE_IGNORE ){
aXRef[j] = -1;
}
}
#endif
}
assert( (chngRowid & chngPk)==0 );
assert( chngRowid==0 || chngRowid==1 );
assert( chngPk==0 || chngPk==1 );
chngKey = chngRowid + chngPk;
/* The SET expressions are not actually used inside the WHERE loop.
** So reset the colUsed mask. Unless this is a virtual table. In that
** case, set all bits of the colUsed mask (to ensure that the virtual
** table implementation makes all columns available).
*/
pTabList->a[0].colUsed = IsVirtual(pTab) ? ALLBITS : 0;
hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngKey);
/* There is one entry in the aRegIdx[] array for each index on the table
** being updated. Fill in aRegIdx[] with a register number that will hold
** the key for accessing each index.
*/
if( onError==OE_Replace ) bReplace = 1;
for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
int reg;
if( chngKey || hasFK>1 || pIdx==pPk
|| indexWhereClauseMightChange(pIdx,aXRef,chngRowid)
){
reg = ++pParse->nMem;
pParse->nMem += pIdx->nColumn;
}else{
reg = 0;
for(i=0; i<pIdx->nKeyCol; i++){
if( indexColumnIsBeingUpdated(pIdx, i, aXRef, chngRowid) ){
reg = ++pParse->nMem;
pParse->nMem += pIdx->nColumn;
if( onError==OE_Default && pIdx->onError==OE_Replace ){
bReplace = 1;
}
break;
}
}
}
if( reg==0 ) aToOpen[j+1] = 0;
aRegIdx[j] = reg;
}
if( bReplace ){
/* If REPLACE conflict resolution might be invoked, open cursors on all
** indexes in case they are needed to delete records. */
memset(aToOpen, 1, nIdx+1);
}
/* Begin generating code. */
v = sqlite3GetVdbe(pParse);
if( v==0 ) goto update_cleanup;
if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
sqlite3BeginWriteOperation(pParse, pTrigger || hasFK, iDb);
/* Allocate required registers. */
if( !IsVirtual(pTab) ){
regRowSet = ++pParse->nMem;
regOldRowid = regNewRowid = ++pParse->nMem;
if( chngPk || pTrigger || hasFK ){
regOld = pParse->nMem + 1;
pParse->nMem += pTab->nCol;
}
if( chngKey || pTrigger || hasFK ){
regNewRowid = ++pParse->nMem;
}
regNew = pParse->nMem + 1;
pParse->nMem += pTab->nCol;
}
/* Start the view context. */
if( isView ){
sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
}
/* If we are trying to update a view, realize that view into
** an ephemeral table.
*/
#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
if( isView ){
sqlite3MaterializeView(pParse, pTab,
pWhere, pOrderBy, pLimit, iDataCur
);
pOrderBy = 0;
pLimit = 0;
}
#endif
/* Resolve the column names in all the expressions in the
** WHERE clause.
*/
if( sqlite3ResolveExprNames(&sNC, pWhere) ){
goto update_cleanup;
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Virtual tables must be handled separately */
if( IsVirtual(pTab) ){
updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef,
pWhere, onError);
goto update_cleanup;
}
#endif
/* Jump to labelBreak to abandon further processing of this UPDATE */
labelContinue = labelBreak = sqlite3VdbeMakeLabel(pParse);
/* Not an UPSERT. Normal processing. Begin by
** initialize the count of updated rows */
if( (db->flags&SQLITE_CountRows)!=0
&& !pParse->pTriggerTab
&& !pParse->nested
&& pUpsert==0
){
regRowCount = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);
}
if( HasRowid(pTab) ){
sqlite3VdbeAddOp3(v, OP_Null, 0, regRowSet, regOldRowid);
}else{
assert( pPk!=0 );
nPk = pPk->nKeyCol;
iPk = pParse->nMem+1;
pParse->nMem += nPk;
regKey = ++pParse->nMem;
if( pUpsert==0 ){
iEph = pParse->nTab++;
sqlite3VdbeAddOp3(v, OP_Null, 0, iPk, iPk+nPk-1);
addrOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEph, nPk);
sqlite3VdbeSetP4KeyInfo(pParse, pPk);
}
}
if( pUpsert ){
/* If this is an UPSERT, then all cursors have already been opened by
** the outer INSERT and the data cursor should be pointing at the row
** that is to be updated. So bypass the code that searches for the
** row(s) to be updated.
*/
pWInfo = 0;
eOnePass = ONEPASS_SINGLE;
sqlite3ExprIfFalse(pParse, pWhere, labelBreak, SQLITE_JUMPIFNULL);
}else{
/* Begin the database scan.
**
** Do not consider a single-pass strategy for a multi-row update if
** there are any triggers or foreign keys to process, or rows may
** be deleted as a result of REPLACE conflict handling. Any of these
** things might disturb a cursor being used to scan through the table
** or index, causing a single-pass approach to malfunction. */
flags = WHERE_ONEPASS_DESIRED|WHERE_SEEK_UNIQ_TABLE;
if( !pParse->nested && !pTrigger && !hasFK && !chngKey && !bReplace ){
flags |= WHERE_ONEPASS_MULTIROW;
}
pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, flags, iIdxCur);
if( pWInfo==0 ) goto update_cleanup;
/* A one-pass strategy that might update more than one row may not
** be used if any column of the index used for the scan is being
** updated. Otherwise, if there is an index on "b", statements like
** the following could create an infinite loop:
**
** UPDATE t1 SET b=b+1 WHERE b>?
**
** Fall back to ONEPASS_OFF if where.c has selected a ONEPASS_MULTI
** strategy that uses an index for which one or more columns are being
** updated. */
eOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
if( eOnePass!=ONEPASS_SINGLE ){
sqlite3MultiWrite(pParse);
if( eOnePass==ONEPASS_MULTI ){
int iCur = aiCurOnePass[1];
if( iCur>=0 && iCur!=iDataCur && aToOpen[iCur-iBaseCur] ){
eOnePass = ONEPASS_OFF;
}
assert( iCur!=iDataCur || !HasRowid(pTab) );
}
}
}
if( HasRowid(pTab) ){
/* Read the rowid of the current row of the WHERE scan. In ONEPASS_OFF
** mode, write the rowid into the FIFO. In either of the one-pass modes,
** leave it in register regOldRowid. */
sqlite3VdbeAddOp2(v, OP_Rowid, iDataCur, regOldRowid);
if( eOnePass==ONEPASS_OFF ){
sqlite3VdbeAddOp2(v, OP_RowSetAdd, regRowSet, regOldRowid);
}
}else{
/* Read the PK of the current row into an array of registers. In
** ONEPASS_OFF mode, serialize the array into a record and store it in
** the ephemeral table. Or, in ONEPASS_SINGLE or MULTI mode, change
** the OP_OpenEphemeral instruction to a Noop (the ephemeral table
** is not required) and leave the PK fields in the array of registers. */
for(i=0; i<nPk; i++){
assert( pPk->aiColumn[i]>=0 );
sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur,pPk->aiColumn[i],iPk+i);
}
if( eOnePass ){
if( addrOpen ) sqlite3VdbeChangeToNoop(v, addrOpen);
nKey = nPk;
regKey = iPk;
}else{
sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, regKey,
sqlite3IndexAffinityStr(db, pPk), nPk);
sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iEph, regKey, iPk, nPk);
}
}
if( pUpsert==0 ){
if( eOnePass!=ONEPASS_MULTI ){
sqlite3WhereEnd(pWInfo);
}
if( !isView ){
int addrOnce = 0;
/* Open every index that needs updating. */
if( eOnePass!=ONEPASS_OFF ){
if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iBaseCur] = 0;
if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iBaseCur] = 0;
}
if( eOnePass==ONEPASS_MULTI && (nIdx-(aiCurOnePass[1]>=0))>0 ){
addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
}
sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, 0, iBaseCur,
aToOpen, 0, 0);
if( addrOnce ) sqlite3VdbeJumpHere(v, addrOnce);
}
/* Top of the update loop */
if( eOnePass!=ONEPASS_OFF ){
if( !isView && aiCurOnePass[0]!=iDataCur && aiCurOnePass[1]!=iDataCur ){
assert( pPk );
sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelBreak, regKey,nKey);
VdbeCoverage(v);
}
if( eOnePass!=ONEPASS_SINGLE ){
labelContinue = sqlite3VdbeMakeLabel(pParse);
}
sqlite3VdbeAddOp2(v, OP_IsNull, pPk ? regKey : regOldRowid, labelBreak);
VdbeCoverageIf(v, pPk==0);
VdbeCoverageIf(v, pPk!=0);
}else if( pPk ){
labelContinue = sqlite3VdbeMakeLabel(pParse);
sqlite3VdbeAddOp2(v, OP_Rewind, iEph, labelBreak); VdbeCoverage(v);
addrTop = sqlite3VdbeAddOp2(v, OP_RowData, iEph, regKey);
sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue, regKey, 0);
VdbeCoverage(v);
}else{
labelContinue = sqlite3VdbeAddOp3(v, OP_RowSetRead, regRowSet,labelBreak,
regOldRowid);
VdbeCoverage(v);
sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid);
VdbeCoverage(v);
}
}
/* If the rowid value will change, set register regNewRowid to
** contain the new value. If the rowid is not being modified,
** then regNewRowid is the same register as regOldRowid, which is
** already populated. */
assert( chngKey || pTrigger || hasFK || regOldRowid==regNewRowid );
if( chngRowid ){
sqlite3ExprCode(pParse, pRowidExpr, regNewRowid);
sqlite3VdbeAddOp1(v, OP_MustBeInt, regNewRowid); VdbeCoverage(v);
}
/* Compute the old pre-UPDATE content of the row being changed, if that
** information is needed */
if( chngPk || hasFK || pTrigger ){
u32 oldmask = (hasFK ? sqlite3FkOldmask(pParse, pTab) : 0);
oldmask |= sqlite3TriggerColmask(pParse,
pTrigger, pChanges, 0, TRIGGER_BEFORE|TRIGGER_AFTER, pTab, onError
);
for(i=0; i<pTab->nCol; i++){
if( oldmask==0xffffffff
|| (i<32 && (oldmask & MASKBIT32(i))!=0)
|| (pTab->aCol[i].colFlags & COLFLAG_PRIMKEY)!=0
){
testcase( oldmask!=0xffffffff && i==31 );
sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regOld+i);
}else{
sqlite3VdbeAddOp2(v, OP_Null, 0, regOld+i);
}
}
if( chngRowid==0 && pPk==0 ){
sqlite3VdbeAddOp2(v, OP_Copy, regOldRowid, regNewRowid);
}
}
/* Populate the array of registers beginning at regNew with the new
** row data. This array is used to check constants, create the new
** table and index records, and as the values for any new.* references
** made by triggers.
**
** If there are one or more BEFORE triggers, then do not populate the
** registers associated with columns that are (a) not modified by
** this UPDATE statement and (b) not accessed by new.* references. The
** values for registers not modified by the UPDATE must be reloaded from
** the database after the BEFORE triggers are fired anyway (as the trigger
** may have modified them). So not loading those that are not going to
** be used eliminates some redundant opcodes.
*/
newmask = sqlite3TriggerColmask(
pParse, pTrigger, pChanges, 1, TRIGGER_BEFORE, pTab, onError
);
for(i=0; i<pTab->nCol; i++){
if( i==pTab->iPKey ){
sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i);
}else{
j = aXRef[i];
if( j>=0 ){
sqlite3ExprCode(pParse, pChanges->a[j].pExpr, regNew+i);
}else if( 0==(tmask&TRIGGER_BEFORE) || i>31 || (newmask & MASKBIT32(i)) ){
/* This branch loads the value of a column that will not be changed
** into a register. This is done if there are no BEFORE triggers, or
** if there are one or more BEFORE triggers that use this value via
** a new.* reference in a trigger program.
*/
testcase( i==31 );
testcase( i==32 );
sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regNew+i);
}else{
sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i);
}
}
}
/* Fire any BEFORE UPDATE triggers. This happens before constraints are
** verified. One could argue that this is wrong.
*/
if( tmask&TRIGGER_BEFORE ){
sqlite3TableAffinity(v, pTab, regNew);
sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges,
TRIGGER_BEFORE, pTab, regOldRowid, onError, labelContinue);
/* The row-trigger may have deleted the row being updated. In this
** case, jump to the next row. No updates or AFTER triggers are
** required. This behavior - what happens when the row being updated
** is deleted or renamed by a BEFORE trigger - is left undefined in the
** documentation.
*/
if( pPk ){
sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue,regKey,nKey);
VdbeCoverage(v);
}else{
sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid);
VdbeCoverage(v);
}
/* After-BEFORE-trigger-reload-loop:
** If it did not delete it, the BEFORE trigger may still have modified
** some of the columns of the row being updated. Load the values for
** all columns not modified by the update statement into their registers
** in case this has happened. Only unmodified columns are reloaded.
** The values computed for modified columns use the values before the
** BEFORE trigger runs. See test case trigger1-18.0 (added 2018-04-26)
** for an example.
*/
for(i=0; i<pTab->nCol; i++){
if( aXRef[i]<0 && i!=pTab->iPKey ){
sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regNew+i);
}
}
}
if( !isView ){
int addr1 = 0; /* Address of jump instruction */
/* Do constraint checks. */
assert( regOldRowid>0 );
sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,
regNewRowid, regOldRowid, chngKey, onError, labelContinue, &bReplace,
aXRef, 0);
/* Do FK constraint checks. */
if( hasFK ){
sqlite3FkCheck(pParse, pTab, regOldRowid, 0, aXRef, chngKey);
}
/* Delete the index entries associated with the current record. */
if( bReplace || chngKey ){
if( pPk ){
addr1 = sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, 0, regKey, nKey);
}else{
addr1 = sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, 0, regOldRowid);
}
VdbeCoverageNeverTaken(v);
}
sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, aRegIdx, -1);
/* If changing the rowid value, or if there are foreign key constraints
** to process, delete the old record. Otherwise, add a noop OP_Delete
** to invoke the pre-update hook.
**
** That (regNew==regnewRowid+1) is true is also important for the
** pre-update hook. If the caller invokes preupdate_new(), the returned
** value is copied from memory cell (regNewRowid+1+iCol), where iCol
** is the column index supplied by the user.
*/
assert( regNew==regNewRowid+1 );
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
sqlite3VdbeAddOp3(v, OP_Delete, iDataCur,
OPFLAG_ISUPDATE | ((hasFK>1 || chngKey) ? 0 : OPFLAG_ISNOOP),
regNewRowid
);
if( eOnePass==ONEPASS_MULTI ){
assert( hasFK==0 && chngKey==0 );
sqlite3VdbeChangeP5(v, OPFLAG_SAVEPOSITION);
}
if( !pParse->nested ){
sqlite3VdbeAppendP4(v, pTab, P4_TABLE);
}
#else
if( hasFK>1 || chngKey ){
sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, 0);
}
#endif
if( bReplace || chngKey ){
sqlite3VdbeJumpHere(v, addr1);
}
if( hasFK ){
sqlite3FkCheck(pParse, pTab, 0, regNewRowid, aXRef, chngKey);
}
/* Insert the new index entries and the new record. */
sqlite3CompleteInsertion(
pParse, pTab, iDataCur, iIdxCur, regNewRowid, aRegIdx,
OPFLAG_ISUPDATE | (eOnePass==ONEPASS_MULTI ? OPFLAG_SAVEPOSITION : 0),
0, 0
);
/* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to
** handle rows (possibly in other tables) that refer via a foreign key
** to the row just updated. */
if( hasFK ){
sqlite3FkActions(pParse, pTab, pChanges, regOldRowid, aXRef, chngKey);
}
}
/* Increment the row counter
*/
if( regRowCount ){
sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);
}
sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges,
TRIGGER_AFTER, pTab, regOldRowid, onError, labelContinue);
/* Repeat the above with the next record to be updated, until
** all record selected by the WHERE clause have been updated.
*/
if( eOnePass==ONEPASS_SINGLE ){
/* Nothing to do at end-of-loop for a single-pass */
}else if( eOnePass==ONEPASS_MULTI ){
sqlite3VdbeResolveLabel(v, labelContinue);
sqlite3WhereEnd(pWInfo);
}else if( pPk ){
sqlite3VdbeResolveLabel(v, labelContinue);
sqlite3VdbeAddOp2(v, OP_Next, iEph, addrTop); VdbeCoverage(v);
}else{
sqlite3VdbeGoto(v, labelContinue);
}
sqlite3VdbeResolveLabel(v, labelBreak);
/* Update the sqlite_sequence table by storing the content of the
** maximum rowid counter values recorded while inserting into
** autoincrement tables.
*/
if( pParse->nested==0 && pParse->pTriggerTab==0 && pUpsert==0 ){
sqlite3AutoincrementEnd(pParse);
}
/*
** Return the number of rows that were changed, if we are tracking
** that information.
*/
if( regRowCount ){
sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1);
sqlite3VdbeSetNumCols(v, 1);
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows updated", SQLITE_STATIC);
}
update_cleanup:
sqlite3AuthContextPop(&sContext);
sqlite3DbFree(db, aXRef); /* Also frees aRegIdx[] and aToOpen[] */
sqlite3SrcListDelete(db, pTabList);
sqlite3ExprListDelete(db, pChanges);
sqlite3ExprDelete(db, pWhere);
#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT)
sqlite3ExprListDelete(db, pOrderBy);
sqlite3ExprDelete(db, pLimit);
#endif
return;
}
/*
** Process an UPDATE statement.
**
** UPDATE OR IGNORE table_wxyz SET a=b, c=d WHERE e<5 AND f NOT NULL;
** \_______/ \________/ \______/ \________________/
* onError pTabList pChanges pWhere
*/
void sqlite3Update(
Parse *pParse, /* The parser context */
SrcList *pTabList, /* The table in which we should change things */
ExprList *pChanges, /* Things to be changed */
Expr *pWhere, /* The WHERE clause. May be null */
int onError /* How to handle constraint errors */
){
int i, j; /* Loop counters */
Table *pTab; /* The table to be updated */
int addr = 0; /* VDBE instruction address of the start of the loop */
WhereInfo *pWInfo; /* Information about the WHERE clause */
Vdbe *v; /* The virtual database engine */
Index *pIdx; /* For looping over indices */
int nIdx; /* Number of indices that need updating */
int nIdxTotal; /* Total number of indices */
int iCur; /* VDBE Cursor number of pTab */
sqlite3 *db; /* The database structure */
Index **apIdx = 0; /* An array of indices that need updating too */
char *aIdxUsed = 0; /* aIdxUsed[i]==1 if the i-th index is used */
int *aXRef = 0; /* aXRef[i] is the index in pChanges->a[] of the
** an expression for the i-th column of the table.
** aXRef[i]==-1 if the i-th column is not changed. */
int chngRowid; /* True if the record number is being changed */
Expr *pRowidExpr = 0; /* Expression defining the new record number */
int openAll = 0; /* True if all indices need to be opened */
AuthContext sContext; /* The authorization context */
NameContext sNC; /* The name-context to resolve expressions in */
int iDb; /* Database containing the table being updated */
#ifndef SQLITE_OMIT_TRIGGER
int isView; /* Trying to update a view */
int triggers_exist = 0; /* True if any row triggers exist */
#endif
int newIdx = -1; /* index of trigger "new" temp table */
int oldIdx = -1; /* index of trigger "old" temp table */
sContext.pParse = 0;
if( pParse->nErr || sqlite3MallocFailed() ){
goto update_cleanup;
}
db = pParse->db;
assert( pTabList->nSrc==1 );
/* Locate the table which we want to update.
*/
pTab = sqlite3SrcListLookup(pParse, pTabList);
if( pTab==0 ) goto update_cleanup;
iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
/* Figure out if we have any triggers and if the table being
** updated is a view
*/
#ifndef SQLITE_OMIT_TRIGGER
triggers_exist = sqlite3TriggersExist(pParse, pTab, TK_UPDATE, pChanges);
isView = pTab->pSelect!=0;
#else
# define triggers_exist 0
# define isView 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif
if( sqlite3IsReadOnly(pParse, pTab, triggers_exist) ){
goto update_cleanup;
}
if( isView ){
if( sqlite3ViewGetColumnNames(pParse, pTab) ){
goto update_cleanup;
}
}
aXRef = sqliteMallocRaw( sizeof(int) * pTab->nCol );
if( aXRef==0 ) goto update_cleanup;
for(i=0; i<pTab->nCol; i++) aXRef[i] = -1;
/* If there are FOR EACH ROW triggers, allocate cursors for the
** special OLD and NEW tables
*/
if( triggers_exist ){
newIdx = pParse->nTab++;
oldIdx = pParse->nTab++;
}
/* Allocate a cursors for the main database table and for all indices.
** The index cursors might not be used, but if they are used they
** need to occur right after the database cursor. So go ahead and
** allocate enough space, just in case.
*/
pTabList->a[0].iCursor = iCur = pParse->nTab++;
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
pParse->nTab++;
}
/* Initialize the name-context */
memset(&sNC, 0, sizeof(sNC));
sNC.pParse = pParse;
sNC.pSrcList = pTabList;
/* Resolve the column names in all the expressions of the
** of the UPDATE statement. Also find the column index
** for each column to be updated in the pChanges array. For each
** column to be updated, make sure we have authorization to change
** that column.
*/
chngRowid = 0;
for(i=0; i<pChanges->nExpr; i++){
if( sqlite3ExprResolveNames(&sNC, pChanges->a[i].pExpr) ){
goto update_cleanup;
}
for(j=0; j<pTab->nCol; j++){
if( sqlite3StrICmp(pTab->aCol[j].zName, pChanges->a[i].zName)==0 ){
if( j==pTab->iPKey ){
chngRowid = 1;
pRowidExpr = pChanges->a[i].pExpr;
}
aXRef[j] = i;
break;
}
}
if( j>=pTab->nCol ){
if( sqlite3IsRowid(pChanges->a[i].zName) ){
chngRowid = 1;
pRowidExpr = pChanges->a[i].pExpr;
}else{
sqlite3ErrorMsg(pParse, "no such column: %s", pChanges->a[i].zName);
goto update_cleanup;
}
}
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int rc;
rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName,
pTab->aCol[j].zName, db->aDb[iDb].zName);
if( rc==SQLITE_DENY ){
goto update_cleanup;
}else if( rc==SQLITE_IGNORE ){
aXRef[j] = -1;
}
}
#endif
}
/* Allocate memory for the array apIdx[] and fill it with pointers to every
** index that needs to be updated. Indices only need updating if their
** key includes one of the columns named in pChanges or if the record
** number of the original table entry is changing.
*/
for(nIdx=nIdxTotal=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdxTotal++){
if( chngRowid ){
i = 0;
}else {
for(i=0; i<pIdx->nColumn; i++){
if( aXRef[pIdx->aiColumn[i]]>=0 ) break;
}
}
if( i<pIdx->nColumn ) nIdx++;
}
if( nIdxTotal>0 ){
apIdx = sqliteMallocRaw( sizeof(Index*) * nIdx + nIdxTotal );
if( apIdx==0 ) goto update_cleanup;
aIdxUsed = (char*)&apIdx[nIdx];
}
for(nIdx=j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
if( chngRowid ){
i = 0;
}else{
for(i=0; i<pIdx->nColumn; i++){
if( aXRef[pIdx->aiColumn[i]]>=0 ) break;
}
}
if( i<pIdx->nColumn ){
apIdx[nIdx++] = pIdx;
aIdxUsed[j] = 1;
}else{
aIdxUsed[j] = 0;
}
}
/* Resolve the column names in all the expressions in the
** WHERE clause.
*/
if( sqlite3ExprResolveNames(&sNC, pWhere) ){
goto update_cleanup;
}
/* Start the view context
*/
if( isView ){
sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
}
/* Begin generating code.
*/
v = sqlite3GetVdbe(pParse);
if( v==0 ) goto update_cleanup;
if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
sqlite3BeginWriteOperation(pParse, 1, iDb);
/* If we are trying to update a view, realize that view into
** a ephemeral table.
*/
if( isView ){
Select *pView;
pView = sqlite3SelectDup(pTab->pSelect);
sqlite3Select(pParse, pView, SRT_VirtualTab, iCur, 0, 0, 0, 0);
sqlite3SelectDelete(pView);
}
/* Begin the database scan
*/
pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0);
if( pWInfo==0 ) goto update_cleanup;
/* Remember the index of every item to be updated.
*/
sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0);
sqlite3VdbeAddOp(v, OP_FifoWrite, 0, 0);
/* End the database scan loop.
*/
sqlite3WhereEnd(pWInfo);
/* Initialize the count of updated rows
*/
if( db->flags & SQLITE_CountRows && !pParse->trigStack ){
sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
}
if( triggers_exist ){
/* Create pseudo-tables for NEW and OLD
*/
sqlite3VdbeAddOp(v, OP_OpenPseudo, oldIdx, 0);
sqlite3VdbeAddOp(v, OP_SetNumColumns, oldIdx, pTab->nCol);
sqlite3VdbeAddOp(v, OP_OpenPseudo, newIdx, 0);
sqlite3VdbeAddOp(v, OP_SetNumColumns, newIdx, pTab->nCol);
/* The top of the update loop for when there are triggers.
*/
addr = sqlite3VdbeAddOp(v, OP_FifoRead, 0, 0);
if( !isView ){
sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
/* Open a cursor and make it point to the record that is
** being updated.
*/
sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenRead);
}
sqlite3VdbeAddOp(v, OP_MoveGe, iCur, 0);
/* Generate the OLD table
*/
sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0);
sqlite3VdbeAddOp(v, OP_RowData, iCur, 0);
sqlite3VdbeAddOp(v, OP_Insert, oldIdx, 0);
/* Generate the NEW table
*/
if( chngRowid ){
sqlite3ExprCodeAndCache(pParse, pRowidExpr);
}else{
sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0);
}
for(i=0; i<pTab->nCol; i++){
if( i==pTab->iPKey ){
sqlite3VdbeAddOp(v, OP_Null, 0, 0);
continue;
}
j = aXRef[i];
if( j<0 ){
sqlite3VdbeAddOp(v, OP_Column, iCur, i);
sqlite3ColumnDefault(v, pTab, i);
}else{
sqlite3ExprCodeAndCache(pParse, pChanges->a[j].pExpr);
}
}
sqlite3VdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
if( !isView ){
sqlite3TableAffinityStr(v, pTab);
}
if( pParse->nErr ) goto update_cleanup;
sqlite3VdbeAddOp(v, OP_Insert, newIdx, 0);
if( !isView ){
sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
}
/* Fire the BEFORE and INSTEAD OF triggers
*/
if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_BEFORE, pTab,
newIdx, oldIdx, onError, addr) ){
goto update_cleanup;
}
}
if( !isView ){
/*
** Open every index that needs updating. Note that if any
** index could potentially invoke a REPLACE conflict resolution
** action, then we need to open all indices because we might need
** to be deleting some records.
*/
sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenWrite);
if( onError==OE_Replace ){
openAll = 1;
}else{
openAll = 0;
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
if( pIdx->onError==OE_Replace ){
openAll = 1;
break;
}
}
}
for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
if( openAll || aIdxUsed[i] ){
KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
sqlite3VdbeOp3(v, OP_OpenWrite, iCur+i+1, pIdx->tnum,
(char*)pKey, P3_KEYINFO_HANDOFF);
assert( pParse->nTab>iCur+i+1 );
}
}
/* Loop over every record that needs updating. We have to load
** the old data for each record to be updated because some columns
** might not change and we will need to copy the old value.
** Also, the old data is needed to delete the old index entires.
** So make the cursor point at the old record.
*/
if( !triggers_exist ){
addr = sqlite3VdbeAddOp(v, OP_FifoRead, 0, 0);
sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
}
sqlite3VdbeAddOp(v, OP_NotExists, iCur, addr);
/* If the record number will change, push the record number as it
** will be after the update. (The old record number is currently
** on top of the stack.)
*/
if( chngRowid ){
sqlite3ExprCode(pParse, pRowidExpr);
sqlite3VdbeAddOp(v, OP_MustBeInt, 0, 0);
}
/* Compute new data for this record.
*/
for(i=0; i<pTab->nCol; i++){
if( i==pTab->iPKey ){
sqlite3VdbeAddOp(v, OP_Null, 0, 0);
continue;
}
j = aXRef[i];
if( j<0 ){
sqlite3VdbeAddOp(v, OP_Column, iCur, i);
sqlite3ColumnDefault(v, pTab, i);
}else{
sqlite3ExprCode(pParse, pChanges->a[j].pExpr);
}
}
/* Do constraint checks
*/
sqlite3GenerateConstraintChecks(pParse, pTab, iCur, aIdxUsed, chngRowid, 1,
onError, addr);
/* Delete the old indices for the current record.
*/
sqlite3GenerateRowIndexDelete(db, v, pTab, iCur, aIdxUsed);
/* If changing the record number, delete the old record.
*/
if( chngRowid ){
sqlite3VdbeAddOp(v, OP_Delete, iCur, 0);
}
/* Create the new index entries and the new record.
*/
sqlite3CompleteInsertion(pParse, pTab, iCur, aIdxUsed, chngRowid, 1, -1);
}
/* Increment the row counter
*/
if( db->flags & SQLITE_CountRows && !pParse->trigStack){
sqlite3VdbeAddOp(v, OP_AddImm, 1, 0);
}
/* If there are triggers, close all the cursors after each iteration
** through the loop. The fire the after triggers.
*/
if( triggers_exist ){
if( !isView ){
for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
if( openAll || aIdxUsed[i] )
sqlite3VdbeAddOp(v, OP_Close, iCur+i+1, 0);
}
sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
}
if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_AFTER, pTab,
newIdx, oldIdx, onError, addr) ){
goto update_cleanup;
}
}
/* Repeat the above with the next record to be updated, until
** all record selected by the WHERE clause have been updated.
*/
sqlite3VdbeAddOp(v, OP_Goto, 0, addr);
sqlite3VdbeJumpHere(v, addr);
/* Close all tables if there were no FOR EACH ROW triggers */
if( !triggers_exist ){
for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
if( openAll || aIdxUsed[i] ){
sqlite3VdbeAddOp(v, OP_Close, iCur+i+1, 0);
}
}
sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
}else{
sqlite3VdbeAddOp(v, OP_Close, newIdx, 0);
sqlite3VdbeAddOp(v, OP_Close, oldIdx, 0);
}
/*
** Return the number of rows that were changed. If this routine is
** generating code because of a call to sqlite3NestedParse(), do not
** invoke the callback function.
*/
if( db->flags & SQLITE_CountRows && !pParse->trigStack && pParse->nested==0 ){
sqlite3VdbeAddOp(v, OP_Callback, 1, 0);
sqlite3VdbeSetNumCols(v, 1);
sqlite3VdbeSetColName(v, 0, "rows updated", P3_STATIC);
}
update_cleanup:
sqlite3AuthContextPop(&sContext);
sqliteFree(apIdx);
sqliteFree(aXRef);
sqlite3SrcListDelete(pTabList);
sqlite3ExprListDelete(pChanges);
sqlite3ExprDelete(pWhere);
return;
}
/*
** Generate code to implement the "ALTER TABLE xxx RENAME TO yyy"
** command.
*/
void sqlite3AlterRenameTable(
Parse *pParse, /* Parser context. */
SrcList *pSrc, /* The table to rename. */
Token *pName /* The new table name. */
){
int iDb; /* Database that contains the table */
char *zDb; /* Name of database iDb */
Table *pTab; /* Table being renamed */
char *zName = 0; /* NULL-terminated version of pName */
sqlite3 *db = pParse->db; /* Database connection */
int nTabName; /* Number of UTF-8 characters in zTabName */
const char *zTabName; /* Original name of the table */
Vdbe *v;
#ifndef SQLITE_OMIT_TRIGGER
char *zWhere = 0; /* Where clause to locate temp triggers */
#endif
VTable *pVTab = 0; /* Non-zero if this is a v-tab with an xRename() */
int savedDbFlags; /* Saved value of db->flags */
savedDbFlags = db->flags;
if( NEVER(db->mallocFailed) ) goto exit_rename_table;
assert( pSrc->nSrc==1 );
assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );
pTab = sqlite3LocateTableItem(pParse, 0, &pSrc->a[0]);
if( !pTab ) goto exit_rename_table;
iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
zDb = db->aDb[iDb].zName;
db->flags |= SQLITE_PreferBuiltin;
/* Get a NULL terminated version of the new table name. */
zName = sqlite3NameFromToken(db, pName);
if( !zName ) goto exit_rename_table;
/* Check that a table or index named 'zName' does not already exist
** in database iDb. If so, this is an error.
*/
if( sqlite3FindTable(db, zName, zDb) || sqlite3FindIndex(db, zName, zDb) ){
sqlite3ErrorMsg(pParse,
"there is already another table or index with this name: %s", zName);
goto exit_rename_table;
}
/* Make sure it is not a system table being altered, or a reserved name
** that the table is being renamed to.
*/
if( SQLITE_OK!=isSystemTable(pParse, pTab->zName) ){
goto exit_rename_table;
}
if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){ goto
exit_rename_table;
}
#ifndef SQLITE_OMIT_VIEW
if( pTab->pSelect ){
sqlite3ErrorMsg(pParse, "view %s may not be altered", pTab->zName);
goto exit_rename_table;
}
#endif
#ifndef SQLITE_OMIT_AUTHORIZATION
/* Invoke the authorization callback. */
if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){
goto exit_rename_table;
}
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( sqlite3ViewGetColumnNames(pParse, pTab) ){
goto exit_rename_table;
}
if( IsVirtual(pTab) ){
pVTab = sqlite3GetVTable(db, pTab);
if( pVTab->pVtab->pModule->xRename==0 ){
pVTab = 0;
}
}
#endif
/* Begin a transaction for database iDb.
** Then modify the schema cookie (since the ALTER TABLE modifies the
** schema). Open a statement transaction if the table is a virtual
** table.
*/
v = sqlite3GetVdbe(pParse);
if( v==0 ){
goto exit_rename_table;
}
sqlite3BeginWriteOperation(pParse, pVTab!=0, iDb);
sqlite3ChangeCookie(pParse, iDb);
/* If this is a virtual table, invoke the xRename() function if
** one is defined. The xRename() callback will modify the names
** of any resources used by the v-table implementation (including other
** SQLite tables) that are identified by the name of the virtual table.
*/
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( pVTab ){
int i = ++pParse->nMem;
sqlite3VdbeLoadString(v, i, zName);
sqlite3VdbeAddOp4(v, OP_VRename, i, 0, 0,(const char*)pVTab, P4_VTAB);
sqlite3MayAbort(pParse);
}
#endif
/* figure out how many UTF-8 characters are in zName */
zTabName = pTab->zName;
nTabName = sqlite3Utf8CharLen(zTabName, -1);
#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
if( db->flags&SQLITE_ForeignKeys ){
/* If foreign-key support is enabled, rewrite the CREATE TABLE
** statements corresponding to all child tables of foreign key constraints
** for which the renamed table is the parent table. */
if( (zWhere=whereForeignKeys(pParse, pTab))!=0 ){
sqlite3NestedParse(pParse,
"UPDATE \"%w\".%s SET "
"sql = sqlite_rename_parent(sql, %Q, %Q) "
"WHERE %s;", zDb, SCHEMA_TABLE(iDb), zTabName, zName, zWhere);
sqlite3DbFree(db, zWhere);
}
}
#endif
/* Modify the sqlite_master table to use the new table name. */
sqlite3NestedParse(pParse,
"UPDATE %Q.%s SET "
#ifdef SQLITE_OMIT_TRIGGER
"sql = sqlite_rename_table(sql, %Q), "
#else
"sql = CASE "
"WHEN type = 'trigger' THEN sqlite_rename_trigger(sql, %Q)"
"ELSE sqlite_rename_table(sql, %Q) END, "
#endif
"tbl_name = %Q, "
"name = CASE "
"WHEN type='table' THEN %Q "
"WHEN name LIKE 'sqlite_autoindex%%' AND type='index' THEN "
"'sqlite_autoindex_' || %Q || substr(name,%d+18) "
"ELSE name END "
"WHERE tbl_name=%Q COLLATE nocase AND "
"(type='table' OR type='index' OR type='trigger');",
zDb, SCHEMA_TABLE(iDb), zName, zName, zName,
#ifndef SQLITE_OMIT_TRIGGER
zName,
#endif
zName, nTabName, zTabName
);
#ifndef SQLITE_OMIT_AUTOINCREMENT
/* If the sqlite_sequence table exists in this database, then update
** it with the new table name.
*/
if( sqlite3FindTable(db, "sqlite_sequence", zDb) ){
sqlite3NestedParse(pParse,
"UPDATE \"%w\".sqlite_sequence set name = %Q WHERE name = %Q",
zDb, zName, pTab->zName);
}
#endif
#ifndef SQLITE_OMIT_TRIGGER
/* If there are TEMP triggers on this table, modify the sqlite_temp_master
** table. Don't do this if the table being ALTERed is itself located in
** the temp database.
*/
if( (zWhere=whereTempTriggers(pParse, pTab))!=0 ){
sqlite3NestedParse(pParse,
"UPDATE sqlite_temp_master SET "
"sql = sqlite_rename_trigger(sql, %Q), "
"tbl_name = %Q "
"WHERE %s;", zName, zName, zWhere);
sqlite3DbFree(db, zWhere);
}
#endif
#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
if( db->flags&SQLITE_ForeignKeys ){
FKey *p;
for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){
Table *pFrom = p->pFrom;
if( pFrom!=pTab ){
reloadTableSchema(pParse, p->pFrom, pFrom->zName);
}
}
}
#endif
/* Drop and reload the internal table schema. */
reloadTableSchema(pParse, pTab, zName);
exit_rename_table:
sqlite3SrcListDelete(db, pSrc);
sqlite3DbFree(db, zName);
db->flags = savedDbFlags;
}
/*
** This function is called after an "ALTER TABLE ... ADD" statement
** has been parsed. Argument pColDef contains the text of the new
** column definition.
**
** The Table structure pParse->pNewTable was extended to include
** the new column during parsing.
*/
void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
Table *pNew; /* Copy of pParse->pNewTable */
Table *pTab; /* Table being altered */
int iDb; /* Database number */
const char *zDb; /* Database name */
const char *zTab; /* Table name */
char *zCol; /* Null-terminated column definition */
Column *pCol; /* The new column */
Expr *pDflt; /* Default value for the new column */
sqlite3 *db; /* The database connection; */
db = pParse->db;
if( pParse->nErr || db->mallocFailed ) return;
pNew = pParse->pNewTable;
assert( pNew );
assert( sqlite3BtreeHoldsAllMutexes(db) );
iDb = sqlite3SchemaToIndex(db, pNew->pSchema);
zDb = db->aDb[iDb].zName;
zTab = &pNew->zName[16]; /* Skip the "sqlite_altertab_" prefix on the name */
pCol = &pNew->aCol[pNew->nCol-1];
pDflt = pCol->pDflt;
pTab = sqlite3FindTable(db, zTab, zDb);
assert( pTab );
#ifndef SQLITE_OMIT_AUTHORIZATION
/* Invoke the authorization callback. */
if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){
return;
}
#endif
/* If the default value for the new column was specified with a
** literal NULL, then set pDflt to 0. This simplifies checking
** for an SQL NULL default below.
*/
if( pDflt && pDflt->op==TK_NULL ){
pDflt = 0;
}
/* Check that the new column is not specified as PRIMARY KEY or UNIQUE.
** If there is a NOT NULL constraint, then the default value for the
** column must not be NULL.
*/
if( pCol->colFlags & COLFLAG_PRIMKEY ){
sqlite3ErrorMsg(pParse, "Cannot add a PRIMARY KEY column");
return;
}
if( pNew->pIndex ){
sqlite3ErrorMsg(pParse, "Cannot add a UNIQUE column");
return;
}
if( (db->flags&SQLITE_ForeignKeys) && pNew->pFKey && pDflt ){
sqlite3ErrorMsg(pParse,
"Cannot add a REFERENCES column with non-NULL default value");
return;
}
if( pCol->notNull && !pDflt ){
sqlite3ErrorMsg(pParse,
"Cannot add a NOT NULL column with default value NULL");
return;
}
/* Ensure the default expression is something that sqlite3ValueFromExpr()
** can handle (i.e. not CURRENT_TIME etc.)
*/
if( pDflt ){
sqlite3_value *pVal = 0;
int rc;
rc = sqlite3ValueFromExpr(db, pDflt, SQLITE_UTF8, SQLITE_AFF_BLOB, &pVal);
assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
if( rc!=SQLITE_OK ){
db->mallocFailed = 1;
return;
}
if( !pVal ){
sqlite3ErrorMsg(pParse, "Cannot add a column with non-constant default");
return;
}
sqlite3ValueFree(pVal);
}
/* Modify the CREATE TABLE statement. */
zCol = sqlite3DbStrNDup(db, (char*)pColDef->z, pColDef->n);
if( zCol ){
char *zEnd = &zCol[pColDef->n-1];
int savedDbFlags = db->flags;
while( zEnd>zCol && (*zEnd==';' || sqlite3Isspace(*zEnd)) ){
*zEnd-- = '\0';
}
db->flags |= SQLITE_PreferBuiltin;
sqlite3NestedParse(pParse,
"UPDATE \"%w\".%s SET "
"sql = substr(sql,1,%d) || ', ' || %Q || substr(sql,%d) "
"WHERE type = 'table' AND name = %Q",
zDb, SCHEMA_TABLE(iDb), pNew->addColOffset, zCol, pNew->addColOffset+1,
zTab
);
sqlite3DbFree(db, zCol);
db->flags = savedDbFlags;
}
/* If the default value of the new column is NULL, then set the file
** format to 2. If the default value of the new column is not NULL,
** the file format becomes 3.
*/
sqlite3MinimumFileFormat(pParse, iDb, pDflt ? 3 : 2);
/* Reload the schema of the modified table. */
reloadTableSchema(pParse, pTab, pTab->zName);
}
/*
** Open a blob handle.
*/
int sqlite3_blob_open(
sqlite3* db, /* The database connection */
const char *zDb, /* The attached database containing the blob */
const char *zTable, /* The table containing the blob */
const char *zColumn, /* The column containing the blob */
sqlite_int64 iRow, /* The row containing the glob */
int flags, /* True -> read/write access, false -> read-only */
sqlite3_blob **ppBlob /* Handle for accessing the blob returned here */
){
int nAttempt = 0;
int iCol; /* Index of zColumn in row-record */
/* This VDBE program seeks a btree cursor to the identified
** db/table/row entry. The reason for using a vdbe program instead
** of writing code to use the b-tree layer directly is that the
** vdbe program will take advantage of the various transaction,
** locking and error handling infrastructure built into the vdbe.
**
** After seeking the cursor, the vdbe executes an OP_ResultRow.
** Code external to the Vdbe then "borrows" the b-tree cursor and
** uses it to implement the blob_read(), blob_write() and
** blob_bytes() functions.
**
** The sqlite3_blob_close() function finalizes the vdbe program,
** which closes the b-tree cursor and (possibly) commits the
** transaction.
*/
static const int iLn = VDBE_OFFSET_LINENO(4);
static const VdbeOpList openBlob[] = {
/* {OP_Transaction, 0, 0, 0}, // 0: Inserted separately */
{OP_TableLock, 0, 0, 0}, /* 1: Acquire a read or write lock */
/* One of the following two instructions is replaced by an OP_Noop. */
{OP_OpenRead, 0, 0, 0}, /* 2: Open cursor 0 for reading */
{OP_OpenWrite, 0, 0, 0}, /* 3: Open cursor 0 for read/write */
{OP_Variable, 1, 1, 1}, /* 4: Push the rowid to the stack */
{OP_NotExists, 0, 10, 1}, /* 5: Seek the cursor */
{OP_Column, 0, 0, 1}, /* 6 */
{OP_ResultRow, 1, 0, 0}, /* 7 */
{OP_Goto, 0, 4, 0}, /* 8 */
{OP_Close, 0, 0, 0}, /* 9 */
{OP_Halt, 0, 0, 0}, /* 10 */
};
int rc = SQLITE_OK;
char *zErr = 0;
Table *pTab;
Parse *pParse = 0;
Incrblob *pBlob = 0;
#ifdef SQLITE_ENABLE_API_ARMOR
if( !sqlite3SafetyCheckOk(db) || ppBlob==0 || zTable==0 ){
return SQLITE_MISUSE_BKPT;
}
#endif
flags = !!flags; /* flags = (flags ? 1 : 0); */
*ppBlob = 0;
sqlite3_mutex_enter(db->mutex);
pBlob = (Incrblob *)sqlite3DbMallocZero(db, sizeof(Incrblob));
if( !pBlob ) goto blob_open_out;
pParse = sqlite3StackAllocRaw(db, sizeof(*pParse));
if( !pParse ) goto blob_open_out;
do {
memset(pParse, 0, sizeof(Parse));
pParse->db = db;
sqlite3DbFree(db, zErr);
zErr = 0;
sqlite3BtreeEnterAll(db);
pTab = sqlite3LocateTable(pParse, 0, zTable, zDb);
if( pTab && IsVirtual(pTab) ){
pTab = 0;
sqlite3ErrorMsg(pParse, "cannot open virtual table: %s", zTable);
}
if( pTab && !HasRowid(pTab) ){
pTab = 0;
sqlite3ErrorMsg(pParse, "cannot open table without rowid: %s", zTable);
}
#ifndef SQLITE_OMIT_VIEW
if( pTab && pTab->pSelect ){
pTab = 0;
sqlite3ErrorMsg(pParse, "cannot open view: %s", zTable);
}
#endif
if( !pTab ){
if( pParse->zErrMsg ){
sqlite3DbFree(db, zErr);
zErr = pParse->zErrMsg;
pParse->zErrMsg = 0;
}
rc = SQLITE_ERROR;
sqlite3BtreeLeaveAll(db);
goto blob_open_out;
}
/* Now search pTab for the exact column. */
for(iCol=0; iCol<pTab->nCol; iCol++) {
if( sqlite3StrICmp(pTab->aCol[iCol].zName, zColumn)==0 ){
break;
}
}
if( iCol==pTab->nCol ){
sqlite3DbFree(db, zErr);
zErr = sqlite3MPrintf(db, "no such column: \"%s\"", zColumn);
rc = SQLITE_ERROR;
sqlite3BtreeLeaveAll(db);
goto blob_open_out;
}
/* If the value is being opened for writing, check that the
** column is not indexed, and that it is not part of a foreign key.
** It is against the rules to open a column to which either of these
** descriptions applies for writing. */
if( flags ){
const char *zFault = 0;
Index *pIdx;
#ifndef SQLITE_OMIT_FOREIGN_KEY
if( db->flags&SQLITE_ForeignKeys ){
/* Check that the column is not part of an FK child key definition. It
** is not necessary to check if it is part of a parent key, as parent
** key columns must be indexed. The check below will pick up this
** case. */
FKey *pFKey;
for(pFKey=pTab->pFKey; pFKey; pFKey=pFKey->pNextFrom){
int j;
for(j=0; j<pFKey->nCol; j++){
if( pFKey->aCol[j].iFrom==iCol ){
zFault = "foreign key";
}
}
}
}
#endif
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
int j;
for(j=0; j<pIdx->nKeyCol; j++){
if( pIdx->aiColumn[j]==iCol ){
zFault = "indexed";
}
}
}
if( zFault ){
sqlite3DbFree(db, zErr);
zErr = sqlite3MPrintf(db, "cannot open %s column for writing", zFault);
rc = SQLITE_ERROR;
sqlite3BtreeLeaveAll(db);
goto blob_open_out;
}
}
pBlob->pStmt = (sqlite3_stmt *)sqlite3VdbeCreate(pParse);
assert( pBlob->pStmt || db->mallocFailed );
if( pBlob->pStmt ){
Vdbe *v = (Vdbe *)pBlob->pStmt;
int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
sqlite3VdbeAddOp4Int(v, OP_Transaction, iDb, flags,
pTab->pSchema->schema_cookie,
pTab->pSchema->iGeneration);
sqlite3VdbeChangeP5(v, 1);
sqlite3VdbeAddOpList(v, ArraySize(openBlob), openBlob, iLn);
/* Make sure a mutex is held on the table to be accessed */
sqlite3VdbeUsesBtree(v, iDb);
/* Configure the OP_TableLock instruction */
#ifdef SQLITE_OMIT_SHARED_CACHE
sqlite3VdbeChangeToNoop(v, 1);
#else
sqlite3VdbeChangeP1(v, 1, iDb);
sqlite3VdbeChangeP2(v, 1, pTab->tnum);
sqlite3VdbeChangeP3(v, 1, flags);
sqlite3VdbeChangeP4(v, 1, pTab->zName, P4_TRANSIENT);
#endif
/* Remove either the OP_OpenWrite or OpenRead. Set the P2
** parameter of the other to pTab->tnum. */
sqlite3VdbeChangeToNoop(v, 3 - flags);
sqlite3VdbeChangeP2(v, 2 + flags, pTab->tnum);
sqlite3VdbeChangeP3(v, 2 + flags, iDb);
/* Configure the number of columns. Configure the cursor to
** think that the table has one more column than it really
** does. An OP_Column to retrieve this imaginary column will
** always return an SQL NULL. This is useful because it means
** we can invoke OP_Column to fill in the vdbe cursors type
** and offset cache without causing any IO.
*/
sqlite3VdbeChangeP4(v, 2+flags, SQLITE_INT_TO_PTR(pTab->nCol+1),P4_INT32);
sqlite3VdbeChangeP2(v, 6, pTab->nCol);
if( !db->mallocFailed ){
pParse->nVar = 1;
pParse->nMem = 1;
pParse->nTab = 1;
sqlite3VdbeMakeReady(v, pParse);
}
}
pBlob->flags = flags;
pBlob->iCol = iCol;
pBlob->db = db;
sqlite3BtreeLeaveAll(db);
if( db->mallocFailed ){
goto blob_open_out;
}
sqlite3_bind_int64(pBlob->pStmt, 1, iRow);
rc = blobSeekToRow(pBlob, iRow, &zErr);
} while( (++nAttempt)<SQLITE_MAX_SCHEMA_RETRY && rc==SQLITE_SCHEMA );
blob_open_out:
if( rc==SQLITE_OK && db->mallocFailed==0 ){
*ppBlob = (sqlite3_blob *)pBlob;
}else{
if( pBlob && pBlob->pStmt ) sqlite3VdbeFinalize((Vdbe *)pBlob->pStmt);
sqlite3DbFree(db, pBlob);
}
sqlite3ErrorWithMsg(db, rc, (zErr ? "%s" : 0), zErr);
sqlite3DbFree(db, zErr);
sqlite3ParserReset(pParse);
sqlite3StackFree(db, pParse);
rc = sqlite3ApiExit(db, rc);
sqlite3_mutex_leave(db->mutex);
return rc;
}
/*
** Process a pragma statement.
**
** Pragmas are of this form:
**
** PRAGMA [database.]id [= value]
**
** The identifier might also be a string. The value is a string, and
** identifier, or a number. If minusFlag is true, then the value is
** a number that was preceded by a minus sign.
**
** If the left side is "database.id" then pId1 is the database name
** and pId2 is the id. If the left side is just "id" then pId1 is the
** id and pId2 is any empty string.
*/
void sqlite3Pragma(
Parse *pParse,
Token *pId1, /* First part of [database.]id field */
Token *pId2, /* Second part of [database.]id field, or NULL */
Token *pValue, /* Token for <value>, or NULL */
int minusFlag /* True if a '-' sign preceded <value> */
){
char *zLeft = 0; /* Nul-terminated UTF-8 string <id> */
char *zRight = 0; /* Nul-terminated UTF-8 string <value>, or NULL */
const char *zDb = 0; /* The database name */
Token *pId; /* Pointer to <id> token */
int iDb; /* Database index for <database> */
sqlite3 *db = pParse->db;
Db *pDb;
Vdbe *v = pParse->pVdbe = sqlite3VdbeCreate(db);
if( v==0 ) return;
pParse->nMem = 2;
/* Interpret the [database.] part of the pragma statement. iDb is the
** index of the database this pragma is being applied to in db.aDb[]. */
iDb = sqlite3TwoPartName(pParse, pId1, pId2, &pId);
if( iDb<0 ) return;
pDb = &db->aDb[iDb];
/* If the temp database has been explicitly named as part of the
** pragma, make sure it is open.
*/
if( iDb==1 && sqlite3OpenTempDatabase(pParse) ){
return;
}
zLeft = sqlite3NameFromToken(db, pId);
if( !zLeft ) return;
if( minusFlag ){
zRight = sqlite3MPrintf(db, "-%T", pValue);
}else{
zRight = sqlite3NameFromToken(db, pValue);
}
zDb = ((pId2 && pId2->n>0)?pDb->zName:0);
if( sqlite3AuthCheck(pParse, SQLITE_PRAGMA, zLeft, zRight, zDb) ){
goto pragma_out;
}
#ifndef SQLITE_OMIT_PAGER_PRAGMAS
/*
** PRAGMA [database.]default_cache_size
** PRAGMA [database.]default_cache_size=N
**
** The first form reports the current persistent setting for the
** page cache size. The value returned is the maximum number of
** pages in the page cache. The second form sets both the current
** page cache size value and the persistent page cache size value
** stored in the database file.
**
** The default cache size is stored in meta-value 2 of page 1 of the
** database file. The cache size is actually the absolute value of
** this memory location. The sign of meta-value 2 determines the
** synchronous setting. A negative value means synchronous is off
** and a positive value means synchronous is on.
*/
if( sqlite3StrICmp(zLeft,"default_cache_size")==0 ){
static const VdbeOpList getCacheSize[] = {
{ OP_ReadCookie, 0, 1, 2}, /* 0 */
{ OP_IfPos, 1, 6, 0},
{ OP_Integer, 0, 2, 0},
{ OP_Subtract, 1, 2, 1},
{ OP_IfPos, 1, 6, 0},
{ OP_Integer, 0, 1, 0}, /* 5 */
{ OP_ResultRow, 1, 1, 0},
};
int addr;
if( sqlite3ReadSchema(pParse) ) goto pragma_out;
sqlite3VdbeUsesBtree(v, iDb);
if( !zRight ){
sqlite3VdbeSetNumCols(v, 1);
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cache_size", P4_STATIC);
pParse->nMem += 2;
addr = sqlite3VdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize);
sqlite3VdbeChangeP1(v, addr, iDb);
sqlite3VdbeChangeP1(v, addr+5, SQLITE_DEFAULT_CACHE_SIZE);
}else{
int size = atoi(zRight);
if( size<0 ) size = -size;
sqlite3BeginWriteOperation(pParse, 0, iDb);
sqlite3VdbeAddOp2(v, OP_Integer, size, 1);
sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, 2, 2);
addr = sqlite3VdbeAddOp2(v, OP_IfPos, 2, 0);
sqlite3VdbeAddOp2(v, OP_Integer, -size, 1);
sqlite3VdbeJumpHere(v, addr);
sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, 2, 1);
pDb->pSchema->cache_size = size;
sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
}
}else
/*
** PRAGMA [database.]page_size
** PRAGMA [database.]page_size=N
**
** The first form reports the current setting for the
** database page size in bytes. The second form sets the
** database page size value. The value can only be set if
** the database has not yet been created.
*/
if( sqlite3StrICmp(zLeft,"page_size")==0 ){
Btree *pBt = pDb->pBt;
if( !zRight ){
int size = pBt ? sqlite3BtreeGetPageSize(pBt) : 0;
returnSingleInt(pParse, "page_size", size);
}else{
/* Malloc may fail when setting the page-size, as there is an internal
** buffer that the pager module resizes using sqlite3_realloc().
*/
db->nextPagesize = atoi(zRight);
if( SQLITE_NOMEM==sqlite3BtreeSetPageSize(pBt, db->nextPagesize, -1) ){
db->mallocFailed = 1;
}
}
}else
/*
** PRAGMA [database.]max_page_count
** PRAGMA [database.]max_page_count=N
**
** The first form reports the current setting for the
** maximum number of pages in the database file. The
** second form attempts to change this setting. Both
** forms return the current setting.
*/
if( sqlite3StrICmp(zLeft,"max_page_count")==0 ){
Btree *pBt = pDb->pBt;
int newMax = 0;
if( zRight ){
newMax = atoi(zRight);
}
if( pBt ){
newMax = sqlite3BtreeMaxPageCount(pBt, newMax);
}
returnSingleInt(pParse, "max_page_count", newMax);
}else
/*
** PRAGMA [database.]page_count
**
** Return the number of pages in the specified database.
*/
if( sqlite3StrICmp(zLeft,"page_count")==0 ){
Vdbe *v;
int iReg;
v = sqlite3GetVdbe(pParse);
if( !v || sqlite3ReadSchema(pParse) ) goto pragma_out;
sqlite3CodeVerifySchema(pParse, iDb);
iReg = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Pagecount, iDb, iReg);
sqlite3VdbeAddOp2(v, OP_ResultRow, iReg, 1);
sqlite3VdbeSetNumCols(v, 1);
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "page_count", P4_STATIC);
}else
/*
** PRAGMA [database.]locking_mode
** PRAGMA [database.]locking_mode = (normal|exclusive)
*/
if( sqlite3StrICmp(zLeft,"locking_mode")==0 ){
const char *zRet = "normal";
int eMode = getLockingMode(zRight);
if( pId2->n==0 && eMode==PAGER_LOCKINGMODE_QUERY ){
/* Simple "PRAGMA locking_mode;" statement. This is a query for
** the current default locking mode (which may be different to
** the locking-mode of the main database).
*/
eMode = db->dfltLockMode;
}else{
Pager *pPager;
if( pId2->n==0 ){
/* This indicates that no database name was specified as part
** of the PRAGMA command. In this case the locking-mode must be
** set on all attached databases, as well as the main db file.
**
** Also, the sqlite3.dfltLockMode variable is set so that
** any subsequently attached databases also use the specified
** locking mode.
*/
int ii;
assert(pDb==&db->aDb[0]);
for(ii=2; ii<db->nDb; ii++){
pPager = sqlite3BtreePager(db->aDb[ii].pBt);
sqlite3PagerLockingMode(pPager, eMode);
}
db->dfltLockMode = eMode;
}
pPager = sqlite3BtreePager(pDb->pBt);
eMode = sqlite3PagerLockingMode(pPager, eMode);
}
assert(eMode==PAGER_LOCKINGMODE_NORMAL||eMode==PAGER_LOCKINGMODE_EXCLUSIVE);
if( eMode==PAGER_LOCKINGMODE_EXCLUSIVE ){
zRet = "exclusive";
}
sqlite3VdbeSetNumCols(v, 1);
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "locking_mode", P4_STATIC);
sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, zRet, 0);
sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
}else
/*
** PRAGMA [database.]journal_mode
** PRAGMA [database.]journal_mode = (delete|persist|off)
*/
if( sqlite3StrICmp(zLeft,"journal_mode")==0 ){
int eMode;
static char * const azModeName[] = {"delete", "persist", "off", "truncate"};
if( zRight==0 ){
eMode = PAGER_JOURNALMODE_QUERY;
}else{
int n = strlen(zRight);
eMode = sizeof(azModeName)/sizeof(azModeName[0]) - 1;
while( eMode>=0 && sqlite3StrNICmp(zRight, azModeName[eMode], n)!=0 ){
eMode--;
}
}
if( pId2->n==0 && eMode==PAGER_JOURNALMODE_QUERY ){
/* Simple "PRAGMA journal_mode;" statement. This is a query for
** the current default journal mode (which may be different to
** the journal-mode of the main database).
*/
eMode = db->dfltJournalMode;
}else{
Pager *pPager;
if( pId2->n==0 ){
/* This indicates that no database name was specified as part
** of the PRAGMA command. In this case the journal-mode must be
** set on all attached databases, as well as the main db file.
**
** Also, the sqlite3.dfltJournalMode variable is set so that
** any subsequently attached databases also use the specified
** journal mode.
*/
int ii;
assert(pDb==&db->aDb[0]);
for(ii=1; ii<db->nDb; ii++){
if( db->aDb[ii].pBt ){
pPager = sqlite3BtreePager(db->aDb[ii].pBt);
sqlite3PagerJournalMode(pPager, eMode);
}
}
db->dfltJournalMode = eMode;
}
pPager = sqlite3BtreePager(pDb->pBt);
eMode = sqlite3PagerJournalMode(pPager, eMode);
}
assert( eMode==PAGER_JOURNALMODE_DELETE
|| eMode==PAGER_JOURNALMODE_TRUNCATE
|| eMode==PAGER_JOURNALMODE_PERSIST
|| eMode==PAGER_JOURNALMODE_OFF );
sqlite3VdbeSetNumCols(v, 1);
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "journal_mode", P4_STATIC);
sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0,
azModeName[eMode], P4_STATIC);
sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
}else
/*
** PRAGMA [database.]journal_size_limit
** PRAGMA [database.]journal_size_limit=N
**
** Get or set the (boolean) value of the database 'auto-vacuum' parameter.
*/
if( sqlite3StrICmp(zLeft,"journal_size_limit")==0 ){
Pager *pPager = sqlite3BtreePager(pDb->pBt);
i64 iLimit = -2;
if( zRight ){
int iLimit32 = atoi(zRight);
if( iLimit32<-1 ){
iLimit32 = -1;
}
iLimit = iLimit32;
}
iLimit = sqlite3PagerJournalSizeLimit(pPager, iLimit);
returnSingleInt(pParse, "journal_size_limit", (int)iLimit);
}else
#endif /* SQLITE_OMIT_PAGER_PRAGMAS */
/*
** PRAGMA [database.]auto_vacuum
** PRAGMA [database.]auto_vacuum=N
**
** Get or set the (boolean) value of the database 'auto-vacuum' parameter.
*/
#ifndef SQLITE_OMIT_AUTOVACUUM
if( sqlite3StrICmp(zLeft,"auto_vacuum")==0 ){
Btree *pBt = pDb->pBt;
if( sqlite3ReadSchema(pParse) ){
goto pragma_out;
}
if( !zRight ){
int auto_vacuum =
pBt ? sqlite3BtreeGetAutoVacuum(pBt) : SQLITE_DEFAULT_AUTOVACUUM;
returnSingleInt(pParse, "auto_vacuum", auto_vacuum);
}else{
int eAuto = getAutoVacuum(zRight);
db->nextAutovac = eAuto;
if( eAuto>=0 ){
/* Call SetAutoVacuum() to set initialize the internal auto and
** incr-vacuum flags. This is required in case this connection
** creates the database file. It is important that it is created
** as an auto-vacuum capable db.
*/
int rc = sqlite3BtreeSetAutoVacuum(pBt, eAuto);
if( rc==SQLITE_OK && (eAuto==1 || eAuto==2) ){
/* When setting the auto_vacuum mode to either "full" or
** "incremental", write the value of meta[6] in the database
** file. Before writing to meta[6], check that meta[3] indicates
** that this really is an auto-vacuum capable database.
*/
static const VdbeOpList setMeta6[] = {
{ OP_Transaction, 0, 1, 0}, /* 0 */
{ OP_ReadCookie, 0, 1, 3}, /* 1 */
{ OP_If, 1, 0, 0}, /* 2 */
{ OP_Halt, SQLITE_OK, OE_Abort, 0}, /* 3 */
{ OP_Integer, 0, 1, 0}, /* 4 */
{ OP_SetCookie, 0, 6, 1}, /* 5 */
};
int iAddr;
iAddr = sqlite3VdbeAddOpList(v, ArraySize(setMeta6), setMeta6);
sqlite3VdbeChangeP1(v, iAddr, iDb);
sqlite3VdbeChangeP1(v, iAddr+1, iDb);
sqlite3VdbeChangeP2(v, iAddr+2, iAddr+4);
sqlite3VdbeChangeP1(v, iAddr+4, eAuto-1);
sqlite3VdbeChangeP1(v, iAddr+5, iDb);
sqlite3VdbeUsesBtree(v, iDb);
}
}
}
}else
#endif
/*
** PRAGMA [database.]incremental_vacuum(N)
**
** Do N steps of incremental vacuuming on a database.
*/
#ifndef SQLITE_OMIT_AUTOVACUUM
if( sqlite3StrICmp(zLeft,"incremental_vacuum")==0 ){
int iLimit, addr;
if( sqlite3ReadSchema(pParse) ){
goto pragma_out;
}
if( zRight==0 || !sqlite3GetInt32(zRight, &iLimit) || iLimit<=0 ){
iLimit = 0x7fffffff;
}
sqlite3BeginWriteOperation(pParse, 0, iDb);
sqlite3VdbeAddOp2(v, OP_Integer, iLimit, 1);
addr = sqlite3VdbeAddOp1(v, OP_IncrVacuum, iDb);
sqlite3VdbeAddOp1(v, OP_ResultRow, 1);
sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1);
sqlite3VdbeAddOp2(v, OP_IfPos, 1, addr);
sqlite3VdbeJumpHere(v, addr);
}else
#endif
#ifndef SQLITE_OMIT_PAGER_PRAGMAS
/*
** PRAGMA [database.]cache_size
** PRAGMA [database.]cache_size=N
**
** The first form reports the current local setting for the
** page cache size. The local setting can be different from
** the persistent cache size value that is stored in the database
** file itself. The value returned is the maximum number of
** pages in the page cache. The second form sets the local
** page cache size value. It does not change the persistent
** cache size stored on the disk so the cache size will revert
** to its default value when the database is closed and reopened.
** N should be a positive integer.
*/
if( sqlite3StrICmp(zLeft,"cache_size")==0 ){
if( sqlite3ReadSchema(pParse) ) goto pragma_out;
if( !zRight ){
returnSingleInt(pParse, "cache_size", pDb->pSchema->cache_size);
}else{
int size = atoi(zRight);
if( size<0 ) size = -size;
pDb->pSchema->cache_size = size;
sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
}
}else
/*
** PRAGMA temp_store
** PRAGMA temp_store = "default"|"memory"|"file"
**
** Return or set the local value of the temp_store flag. Changing
** the local value does not make changes to the disk file and the default
** value will be restored the next time the database is opened.
**
** Note that it is possible for the library compile-time options to
** override this setting
*/
if( sqlite3StrICmp(zLeft, "temp_store")==0 ){
if( !zRight ){
returnSingleInt(pParse, "temp_store", db->temp_store);
}else{
changeTempStorage(pParse, zRight);
}
}else
/*
** PRAGMA temp_store_directory
** PRAGMA temp_store_directory = ""|"directory_name"
**
** Return or set the local value of the temp_store_directory flag. Changing
** the value sets a specific directory to be used for temporary files.
** Setting to a null string reverts to the default temporary directory search.
** If temporary directory is changed, then invalidateTempStorage.
**
*/
if( sqlite3StrICmp(zLeft, "temp_store_directory")==0 ){
if( !zRight ){
if( sqlite3_temp_directory ){
sqlite3VdbeSetNumCols(v, 1);
sqlite3VdbeSetColName(v, 0, COLNAME_NAME,
"temp_store_directory", P4_STATIC);
sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, sqlite3_temp_directory, 0);
sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
}
}else{
#ifndef SQLITE_OMIT_WSD
if( zRight[0] ){
int rc;
int res;
rc = sqlite3OsAccess(db->pVfs, zRight, SQLITE_ACCESS_READWRITE, &res);
if( rc!=SQLITE_OK || res==0 ){
sqlite3ErrorMsg(pParse, "not a writable directory");
goto pragma_out;
}
}
if( SQLITE_TEMP_STORE==0
|| (SQLITE_TEMP_STORE==1 && db->temp_store<=1)
|| (SQLITE_TEMP_STORE==2 && db->temp_store==1)
){
invalidateTempStorage(pParse);
}
sqlite3_free(sqlite3_temp_directory);
if( zRight[0] ){
sqlite3_temp_directory = sqlite3DbStrDup(0, zRight);
}else{
sqlite3_temp_directory = 0;
}
#endif /* SQLITE_OMIT_WSD */
}
}else
/*
** PRAGMA [database.]synchronous
** PRAGMA [database.]synchronous=OFF|ON|NORMAL|FULL
**
** Return or set the local value of the synchronous flag. Changing
** the local value does not make changes to the disk file and the
** default value will be restored the next time the database is
** opened.
*/
if( sqlite3StrICmp(zLeft,"synchronous")==0 ){
if( sqlite3ReadSchema(pParse) ) goto pragma_out;
if( !zRight ){
returnSingleInt(pParse, "synchronous", pDb->safety_level-1);
}else{
if( !db->autoCommit ){
sqlite3ErrorMsg(pParse,
"Safety level may not be changed inside a transaction");
}else{
pDb->safety_level = getSafetyLevel(zRight)+1;
}
}
}else
#endif /* SQLITE_OMIT_PAGER_PRAGMAS */
#ifndef SQLITE_OMIT_FLAG_PRAGMAS
if( flagPragma(pParse, zLeft, zRight) ){
/* The flagPragma() subroutine also generates any necessary code
** there is nothing more to do here */
}else
#endif /* SQLITE_OMIT_FLAG_PRAGMAS */
#ifndef SQLITE_OMIT_SCHEMA_PRAGMAS
/*
** PRAGMA table_info(<table>)
**
** Return a single row for each column of the named table. The columns of
** the returned data set are:
**
** cid: Column id (numbered from left to right, starting at 0)
** name: Column name
** type: Column declaration type.
** notnull: True if 'NOT NULL' is part of column declaration
** dflt_value: The default value for the column, if any.
*/
if( sqlite3StrICmp(zLeft, "table_info")==0 && zRight ){
Table *pTab;
if( sqlite3ReadSchema(pParse) ) goto pragma_out;
pTab = sqlite3FindTable(db, zRight, zDb);
if( pTab ){
int i;
int nHidden = 0;
Column *pCol;
sqlite3VdbeSetNumCols(v, 6);
pParse->nMem = 6;
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cid", P4_STATIC);
sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P4_STATIC);
sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "type", P4_STATIC);
sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "notnull", P4_STATIC);
sqlite3VdbeSetColName(v, 4, COLNAME_NAME, "dflt_value", P4_STATIC);
sqlite3VdbeSetColName(v, 5, COLNAME_NAME, "pk", P4_STATIC);
sqlite3ViewGetColumnNames(pParse, pTab);
for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){
const Token *pDflt;
if( IsHiddenColumn(pCol) ){
nHidden++;
continue;
}
sqlite3VdbeAddOp2(v, OP_Integer, i-nHidden, 1);
sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pCol->zName, 0);
sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
pCol->zType ? pCol->zType : "", 0);
sqlite3VdbeAddOp2(v, OP_Integer, pCol->notNull, 4);
if( pCol->pDflt && (pDflt = &pCol->pDflt->span)->z ){
sqlite3VdbeAddOp4(v, OP_String8, 0, 5, 0, (char*)pDflt->z, pDflt->n);
}else{
sqlite3VdbeAddOp2(v, OP_Null, 0, 5);
}
sqlite3VdbeAddOp2(v, OP_Integer, pCol->isPrimKey, 6);
sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 6);
}
}
}else
if( sqlite3StrICmp(zLeft, "index_info")==0 && zRight ){
Index *pIdx;
Table *pTab;
if( sqlite3ReadSchema(pParse) ) goto pragma_out;
pIdx = sqlite3FindIndex(db, zRight, zDb);
if( pIdx ){
int i;
pTab = pIdx->pTable;
sqlite3VdbeSetNumCols(v, 3);
pParse->nMem = 3;
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seqno", P4_STATIC);
sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "cid", P4_STATIC);
sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "name", P4_STATIC);
for(i=0; i<pIdx->nColumn; i++){
int cnum = pIdx->aiColumn[i];
sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
sqlite3VdbeAddOp2(v, OP_Integer, cnum, 2);
assert( pTab->nCol>cnum );
sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, pTab->aCol[cnum].zName, 0);
sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
}
}
}else
if( sqlite3StrICmp(zLeft, "index_list")==0 && zRight ){
Index *pIdx;
Table *pTab;
if( sqlite3ReadSchema(pParse) ) goto pragma_out;
pTab = sqlite3FindTable(db, zRight, zDb);
if( pTab ){
v = sqlite3GetVdbe(pParse);
pIdx = pTab->pIndex;
if( pIdx ){
int i = 0;
sqlite3VdbeSetNumCols(v, 3);
pParse->nMem = 3;
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P4_STATIC);
sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P4_STATIC);
sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "unique", P4_STATIC);
while(pIdx){
sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pIdx->zName, 0);
sqlite3VdbeAddOp2(v, OP_Integer, pIdx->onError!=OE_None, 3);
sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
++i;
pIdx = pIdx->pNext;
}
}
}
}else
if( sqlite3StrICmp(zLeft, "database_list")==0 ){
int i;
if( sqlite3ReadSchema(pParse) ) goto pragma_out;
sqlite3VdbeSetNumCols(v, 3);
pParse->nMem = 3;
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P4_STATIC);
sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P4_STATIC);
sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "file", P4_STATIC);
for(i=0; i<db->nDb; i++){
if( db->aDb[i].pBt==0 ) continue;
assert( db->aDb[i].zName!=0 );
sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, db->aDb[i].zName, 0);
sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
sqlite3BtreeGetFilename(db->aDb[i].pBt), 0);
sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
}
}else
if( sqlite3StrICmp(zLeft, "collation_list")==0 ){
int i = 0;
HashElem *p;
sqlite3VdbeSetNumCols(v, 2);
pParse->nMem = 2;
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P4_STATIC);
sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P4_STATIC);
for(p=sqliteHashFirst(&db->aCollSeq); p; p=sqliteHashNext(p)){
CollSeq *pColl = (CollSeq *)sqliteHashData(p);
sqlite3VdbeAddOp2(v, OP_Integer, i++, 1);
sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pColl->zName, 0);
sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 2);
}
}else
#endif /* SQLITE_OMIT_SCHEMA_PRAGMAS */
#ifndef SQLITE_OMIT_FOREIGN_KEY
if( sqlite3StrICmp(zLeft, "foreign_key_list")==0 && zRight ){
FKey *pFK;
Table *pTab;
if( sqlite3ReadSchema(pParse) ) goto pragma_out;
pTab = sqlite3FindTable(db, zRight, zDb);
if( pTab ){
v = sqlite3GetVdbe(pParse);
pFK = pTab->pFKey;
if( pFK ){
int i = 0;
sqlite3VdbeSetNumCols(v, 5);
pParse->nMem = 5;
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "id", P4_STATIC);
sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "seq", P4_STATIC);
sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "table", P4_STATIC);
sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "from", P4_STATIC);
sqlite3VdbeSetColName(v, 4, COLNAME_NAME, "to", P4_STATIC);
while(pFK){
int j;
for(j=0; j<pFK->nCol; j++){
char *zCol = pFK->aCol[j].zCol;
sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
sqlite3VdbeAddOp2(v, OP_Integer, j, 2);
sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, pFK->zTo, 0);
sqlite3VdbeAddOp4(v, OP_String8, 0, 4, 0,
pTab->aCol[pFK->aCol[j].iFrom].zName, 0);
sqlite3VdbeAddOp4(v, zCol ? OP_String8 : OP_Null, 0, 5, 0, zCol, 0);
sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 5);
}
++i;
pFK = pFK->pNextFrom;
}
}
}
}else
#endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */
#ifndef NDEBUG
if( sqlite3StrICmp(zLeft, "parser_trace")==0 ){
if( zRight ){
if( getBoolean(zRight) ){
sqlite3ParserTrace(stderr, "parser: ");
}else{
sqlite3ParserTrace(0, 0);
}
}
}else
#endif
/* Reinstall the LIKE and GLOB functions. The variant of LIKE
** used will be case sensitive or not depending on the RHS.
*/
if( sqlite3StrICmp(zLeft, "case_sensitive_like")==0 ){
if( zRight ){
sqlite3RegisterLikeFunctions(db, getBoolean(zRight));
}
}else
#ifndef SQLITE_INTEGRITY_CHECK_ERROR_MAX
# define SQLITE_INTEGRITY_CHECK_ERROR_MAX 100
#endif
#ifndef SQLITE_OMIT_INTEGRITY_CHECK
/* Pragma "quick_check" is an experimental reduced version of
** integrity_check designed to detect most database corruption
** without most of the overhead of a full integrity-check.
*/
if( sqlite3StrICmp(zLeft, "integrity_check")==0
|| sqlite3StrICmp(zLeft, "quick_check")==0
){
int i, j, addr, mxErr;
/* Code that appears at the end of the integrity check. If no error
** messages have been generated, output OK. Otherwise output the
** error message
*/
static const VdbeOpList endCode[] = {
{ OP_AddImm, 1, 0, 0}, /* 0 */
{ OP_IfNeg, 1, 0, 0}, /* 1 */
{ OP_String8, 0, 3, 0}, /* 2 */
{ OP_ResultRow, 3, 1, 0},
};
int isQuick = (zLeft[0]=='q');
/* Initialize the VDBE program */
if( sqlite3ReadSchema(pParse) ) goto pragma_out;
pParse->nMem = 6;
sqlite3VdbeSetNumCols(v, 1);
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "integrity_check", P4_STATIC);
/* Set the maximum error count */
mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
if( zRight ){
mxErr = atoi(zRight);
if( mxErr<=0 ){
mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
}
}
sqlite3VdbeAddOp2(v, OP_Integer, mxErr, 1); /* reg[1] holds errors left */
/* Do an integrity check on each database file */
for(i=0; i<db->nDb; i++){
HashElem *x;
Hash *pTbls;
int cnt = 0;
if( OMIT_TEMPDB && i==1 ) continue;
sqlite3CodeVerifySchema(pParse, i);
addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1); /* Halt if out of errors */
sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
sqlite3VdbeJumpHere(v, addr);
/* Do an integrity check of the B-Tree
**
** Begin by filling registers 2, 3, ... with the root pages numbers
** for all tables and indices in the database.
*/
pTbls = &db->aDb[i].pSchema->tblHash;
for(x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
Table *pTab = sqliteHashData(x);
Index *pIdx;
sqlite3VdbeAddOp2(v, OP_Integer, pTab->tnum, 2+cnt);
cnt++;
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
sqlite3VdbeAddOp2(v, OP_Integer, pIdx->tnum, 2+cnt);
cnt++;
}
}
if( cnt==0 ) continue;
/* Make sure sufficient number of registers have been allocated */
if( pParse->nMem < cnt+4 ){
pParse->nMem = cnt+4;
}
/* Do the b-tree integrity checks */
sqlite3VdbeAddOp3(v, OP_IntegrityCk, 2, cnt, 1);
sqlite3VdbeChangeP5(v, i);
addr = sqlite3VdbeAddOp1(v, OP_IsNull, 2);
sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
sqlite3MPrintf(db, "*** in database %s ***\n", db->aDb[i].zName),
P4_DYNAMIC);
sqlite3VdbeAddOp3(v, OP_Move, 2, 4, 1);
sqlite3VdbeAddOp3(v, OP_Concat, 4, 3, 2);
sqlite3VdbeAddOp2(v, OP_ResultRow, 2, 1);
sqlite3VdbeJumpHere(v, addr);
/* Make sure all the indices are constructed correctly.
*/
for(x=sqliteHashFirst(pTbls); x && !isQuick; x=sqliteHashNext(x)){
Table *pTab = sqliteHashData(x);
Index *pIdx;
int loopTop;
if( pTab->pIndex==0 ) continue;
addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1); /* Stop if out of errors */
sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
sqlite3VdbeJumpHere(v, addr);
sqlite3OpenTableAndIndices(pParse, pTab, 1, OP_OpenRead);
sqlite3VdbeAddOp2(v, OP_Integer, 0, 2); /* reg(2) will count entries */
loopTop = sqlite3VdbeAddOp2(v, OP_Rewind, 1, 0);
sqlite3VdbeAddOp2(v, OP_AddImm, 2, 1); /* increment entry count */
for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
int jmp2;
static const VdbeOpList idxErr[] = {
{ OP_AddImm, 1, -1, 0},
{ OP_String8, 0, 3, 0}, /* 1 */
{ OP_Rowid, 1, 4, 0},
{ OP_String8, 0, 5, 0}, /* 3 */
{ OP_String8, 0, 6, 0}, /* 4 */
{ OP_Concat, 4, 3, 3},
{ OP_Concat, 5, 3, 3},
{ OP_Concat, 6, 3, 3},
{ OP_ResultRow, 3, 1, 0},
{ OP_IfPos, 1, 0, 0}, /* 9 */
{ OP_Halt, 0, 0, 0},
};
sqlite3GenerateIndexKey(pParse, pIdx, 1, 3, 1);
jmp2 = sqlite3VdbeAddOp3(v, OP_Found, j+2, 0, 3);
addr = sqlite3VdbeAddOpList(v, ArraySize(idxErr), idxErr);
sqlite3VdbeChangeP4(v, addr+1, "rowid ", P4_STATIC);
sqlite3VdbeChangeP4(v, addr+3, " missing from index ", P4_STATIC);
sqlite3VdbeChangeP4(v, addr+4, pIdx->zName, P4_STATIC);
sqlite3VdbeJumpHere(v, addr+9);
sqlite3VdbeJumpHere(v, jmp2);
}
sqlite3VdbeAddOp2(v, OP_Next, 1, loopTop+1);
sqlite3VdbeJumpHere(v, loopTop);
for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
static const VdbeOpList cntIdx[] = {
{ OP_Integer, 0, 3, 0},
{ OP_Rewind, 0, 0, 0}, /* 1 */
{ OP_AddImm, 3, 1, 0},
{ OP_Next, 0, 0, 0}, /* 3 */
{ OP_Eq, 2, 0, 3}, /* 4 */
{ OP_AddImm, 1, -1, 0},
{ OP_String8, 0, 2, 0}, /* 6 */
{ OP_String8, 0, 3, 0}, /* 7 */
{ OP_Concat, 3, 2, 2},
{ OP_ResultRow, 2, 1, 0},
};
if( pIdx->tnum==0 ) continue;
addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1);
sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
sqlite3VdbeJumpHere(v, addr);
addr = sqlite3VdbeAddOpList(v, ArraySize(cntIdx), cntIdx);
sqlite3VdbeChangeP1(v, addr+1, j+2);
sqlite3VdbeChangeP2(v, addr+1, addr+4);
sqlite3VdbeChangeP1(v, addr+3, j+2);
sqlite3VdbeChangeP2(v, addr+3, addr+2);
sqlite3VdbeJumpHere(v, addr+4);
sqlite3VdbeChangeP4(v, addr+6,
"wrong # of entries in index ", P4_STATIC);
sqlite3VdbeChangeP4(v, addr+7, pIdx->zName, P4_STATIC);
}
}
}
addr = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode);
sqlite3VdbeChangeP2(v, addr, -mxErr);
sqlite3VdbeJumpHere(v, addr+1);
sqlite3VdbeChangeP4(v, addr+2, "ok", P4_STATIC);
}else
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */
#ifndef SQLITE_OMIT_UTF16
/*
** PRAGMA encoding
** PRAGMA encoding = "utf-8"|"utf-16"|"utf-16le"|"utf-16be"
**
** In its first form, this pragma returns the encoding of the main
** database. If the database is not initialized, it is initialized now.
**
** The second form of this pragma is a no-op if the main database file
** has not already been initialized. In this case it sets the default
** encoding that will be used for the main database file if a new file
** is created. If an existing main database file is opened, then the
** default text encoding for the existing database is used.
**
** In all cases new databases created using the ATTACH command are
** created to use the same default text encoding as the main database. If
** the main database has not been initialized and/or created when ATTACH
** is executed, this is done before the ATTACH operation.
**
** In the second form this pragma sets the text encoding to be used in
** new database files created using this database handle. It is only
** useful if invoked immediately after the main database i
*/
if( sqlite3StrICmp(zLeft, "encoding")==0 ){
static const struct EncName {
char *zName;
u8 enc;
} encnames[] = {
{ "UTF-8", SQLITE_UTF8 },
{ "UTF8", SQLITE_UTF8 },
{ "UTF-16le", SQLITE_UTF16LE },
{ "UTF16le", SQLITE_UTF16LE },
{ "UTF-16be", SQLITE_UTF16BE },
{ "UTF16be", SQLITE_UTF16BE },
{ "UTF-16", 0 }, /* SQLITE_UTF16NATIVE */
{ "UTF16", 0 }, /* SQLITE_UTF16NATIVE */
{ 0, 0 }
};
const struct EncName *pEnc;
if( !zRight ){ /* "PRAGMA encoding" */
if( sqlite3ReadSchema(pParse) ) goto pragma_out;
sqlite3VdbeSetNumCols(v, 1);
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "encoding", P4_STATIC);
sqlite3VdbeAddOp2(v, OP_String8, 0, 1);
for(pEnc=&encnames[0]; pEnc->zName; pEnc++){
if( pEnc->enc==ENC(pParse->db) ){
sqlite3VdbeChangeP4(v, -1, pEnc->zName, P4_STATIC);
break;
}
}
sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
}else{ /* "PRAGMA encoding = XXX" */
/* Only change the value of sqlite.enc if the database handle is not
** initialized. If the main database exists, the new sqlite.enc value
** will be overwritten when the schema is next loaded. If it does not
** already exists, it will be created to use the new encoding value.
*/
if(
!(DbHasProperty(db, 0, DB_SchemaLoaded)) ||
DbHasProperty(db, 0, DB_Empty)
){
for(pEnc=&encnames[0]; pEnc->zName; pEnc++){
if( 0==sqlite3StrICmp(zRight, pEnc->zName) ){
ENC(pParse->db) = pEnc->enc ? pEnc->enc : SQLITE_UTF16NATIVE;
break;
}
}
if( !pEnc->zName ){
sqlite3ErrorMsg(pParse, "unsupported encoding: %s", zRight);
}
}
}
}else
#endif /* SQLITE_OMIT_UTF16 */
#ifndef SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS
/*
** PRAGMA [database.]schema_version
** PRAGMA [database.]schema_version = <integer>
**
** PRAGMA [database.]user_version
** PRAGMA [database.]user_version = <integer>
**
** The pragma's schema_version and user_version are used to set or get
** the value of the schema-version and user-version, respectively. Both
** the schema-version and the user-version are 32-bit signed integers
** stored in the database header.
**
** The schema-cookie is usually only manipulated internally by SQLite. It
** is incremented by SQLite whenever the database schema is modified (by
** creating or dropping a table or index). The schema version is used by
** SQLite each time a query is executed to ensure that the internal cache
** of the schema used when compiling the SQL query matches the schema of
** the database against which the compiled query is actually executed.
** Subverting this mechanism by using "PRAGMA schema_version" to modify
** the schema-version is potentially dangerous and may lead to program
** crashes or database corruption. Use with caution!
**
** The user-version is not used internally by SQLite. It may be used by
** applications for any purpose.
*/
if( sqlite3StrICmp(zLeft, "schema_version")==0
|| sqlite3StrICmp(zLeft, "user_version")==0
|| sqlite3StrICmp(zLeft, "freelist_count")==0
){
int iCookie; /* Cookie index. 0 for schema-cookie, 6 for user-cookie. */
sqlite3VdbeUsesBtree(v, iDb);
switch( zLeft[0] ){
case 's': case 'S':
iCookie = 0;
break;
case 'f': case 'F':
iCookie = 1;
iDb = (-1*(iDb+1));
assert(iDb<=0);
break;
default:
iCookie = 5;
break;
}
if( zRight && iDb>=0 ){
/* Write the specified cookie value */
static const VdbeOpList setCookie[] = {
{ OP_Transaction, 0, 1, 0}, /* 0 */
{ OP_Integer, 0, 1, 0}, /* 1 */
{ OP_SetCookie, 0, 0, 1}, /* 2 */
};
int addr = sqlite3VdbeAddOpList(v, ArraySize(setCookie), setCookie);
sqlite3VdbeChangeP1(v, addr, iDb);
sqlite3VdbeChangeP1(v, addr+1, atoi(zRight));
sqlite3VdbeChangeP1(v, addr+2, iDb);
sqlite3VdbeChangeP2(v, addr+2, iCookie);
}else{
/* Read the specified cookie value */
static const VdbeOpList readCookie[] = {
{ OP_ReadCookie, 0, 1, 0}, /* 0 */
{ OP_ResultRow, 1, 1, 0}
};
int addr = sqlite3VdbeAddOpList(v, ArraySize(readCookie), readCookie);
sqlite3VdbeChangeP1(v, addr, iDb);
sqlite3VdbeChangeP3(v, addr, iCookie);
sqlite3VdbeSetNumCols(v, 1);
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLeft, P4_TRANSIENT);
}
}else
#endif /* SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS */
#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
/*
** Report the current state of file logs for all databases
*/
if( sqlite3StrICmp(zLeft, "lock_status")==0 ){
static const char *const azLockName[] = {
"unlocked", "shared", "reserved", "pending", "exclusive"
};
int i;
Vdbe *v = sqlite3GetVdbe(pParse);
sqlite3VdbeSetNumCols(v, 2);
pParse->nMem = 2;
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "database", P4_STATIC);
sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "status", P4_STATIC);
for(i=0; i<db->nDb; i++){
Btree *pBt;
Pager *pPager;
const char *zState = "unknown";
int j;
if( db->aDb[i].zName==0 ) continue;
sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, db->aDb[i].zName, P4_STATIC);
pBt = db->aDb[i].pBt;
if( pBt==0 || (pPager = sqlite3BtreePager(pBt))==0 ){
zState = "closed";
}else if( sqlite3_file_control(db, i ? db->aDb[i].zName : 0,
SQLITE_FCNTL_LOCKSTATE, &j)==SQLITE_OK ){
zState = azLockName[j];
}
sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, zState, P4_STATIC);
sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 2);
}
}else
#endif
#ifdef SQLITE_SSE
/*
** Check to see if the sqlite_statements table exists. Create it
** if it does not.
*/
if( sqlite3StrICmp(zLeft, "create_sqlite_statement_table")==0 ){
extern int sqlite3CreateStatementsTable(Parse*);
sqlite3CreateStatementsTable(pParse);
}else
#endif
#if SQLITE_HAS_CODEC
if( sqlite3StrICmp(zLeft, "key")==0 ){
sqlite3_key(db, zRight, strlen(zRight));
}else
#endif
#if SQLITE_HAS_CODEC || defined(SQLITE_ENABLE_CEROD)
if( sqlite3StrICmp(zLeft, "activate_extensions")==0 ){
#if SQLITE_HAS_CODEC
if( sqlite3StrNICmp(zRight, "see-", 4)==0 ){
extern void sqlite3_activate_see(const char*);
sqlite3_activate_see(&zRight[4]);
}
#endif
#ifdef SQLITE_ENABLE_CEROD
if( sqlite3StrNICmp(zRight, "cerod-", 6)==0 ){
extern void sqlite3_activate_cerod(const char*);
sqlite3_activate_cerod(&zRight[6]);
}
#endif
}
#endif
{}
if( v ){
/* Code an OP_Expire at the end of each PRAGMA program to cause
** the VDBE implementing the pragma to expire. Most (all?) pragmas
** are only valid for a single execution.
*/
sqlite3VdbeAddOp2(v, OP_Expire, 1, 0);
/*
** Reset the safety level, in case the fullfsync flag or synchronous
** setting changed.
*/
#ifndef SQLITE_OMIT_PAGER_PRAGMAS
if( db->autoCommit ){
sqlite3BtreeSetSafetyLevel(pDb->pBt, pDb->safety_level,
(db->flags&SQLITE_FullFSync)!=0);
}
#endif
}
pragma_out:
sqlite3DbFree(db, zLeft);
sqlite3DbFree(db, zRight);
}
/*
** This function is called by the parser after the table-name in
** an "ALTER TABLE <table-name> ADD" statement is parsed. Argument
** pSrc is the full-name of the table being altered.
**
** This routine makes a (partial) copy of the Table structure
** for the table being altered and sets Parse.pNewTable to point
** to it. Routines called by the parser as the column definition
** is parsed (i.e. sqlite3AddColumn()) add the new Column data to
** the copy. The copy of the Table structure is deleted by tokenize.c
** after parsing is finished.
**
** Routine sqlite3AlterFinishAddColumn() will be called to complete
** coding the "ALTER TABLE ... ADD" statement.
*/
void sqlite3AlterBeginAddColumn(Parse *pParse, SrcList *pSrc){
Table *pNew;
Table *pTab;
Vdbe *v;
int iDb;
int i;
int nAlloc;
/* Look up the table being altered. */
assert( pParse->pNewTable==0 );
if( sqlite3MallocFailed() ) goto exit_begin_add_column;
pTab = sqlite3LocateTable(pParse, pSrc->a[0].zName, pSrc->a[0].zDatabase);
if( !pTab ) goto exit_begin_add_column;
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( IsVirtual(pTab) ){
sqlite3ErrorMsg(pParse, "virtual tables may not be altered");
goto exit_begin_add_column;
}
#endif
/* Make sure this is not an attempt to ALTER a view. */
if( pTab->pSelect ){
sqlite3ErrorMsg(pParse, "Cannot add a column to a view");
goto exit_begin_add_column;
}
assert( pTab->addColOffset>0 );
iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
/* Put a copy of the Table struct in Parse.pNewTable for the
** sqlite3AddColumn() function and friends to modify.
*/
pNew = (Table *)sqliteMalloc(sizeof(Table));
if( !pNew ) goto exit_begin_add_column;
pParse->pNewTable = pNew;
pNew->nRef = 1;
pNew->nCol = pTab->nCol;
assert( pNew->nCol>0 );
nAlloc = (((pNew->nCol-1)/8)*8)+8;
assert( nAlloc>=pNew->nCol && nAlloc%8==0 && nAlloc-pNew->nCol<8 );
pNew->aCol = (Column *)sqliteMalloc(sizeof(Column)*nAlloc);
pNew->zName = sqliteStrDup(pTab->zName);
if( !pNew->aCol || !pNew->zName ){
goto exit_begin_add_column;
}
memcpy(pNew->aCol, pTab->aCol, sizeof(Column)*pNew->nCol);
for(i=0; i<pNew->nCol; i++){
Column *pCol = &pNew->aCol[i];
pCol->zName = sqliteStrDup(pCol->zName);
pCol->zColl = 0;
pCol->zType = 0;
pCol->pDflt = 0;
}
pNew->pSchema = pParse->db->aDb[iDb].pSchema;
pNew->addColOffset = pTab->addColOffset;
pNew->nRef = 1;
/* Begin a transaction and increment the schema cookie. */
sqlite3BeginWriteOperation(pParse, 0, iDb);
v = sqlite3GetVdbe(pParse);
if( !v ) goto exit_begin_add_column;
sqlite3ChangeCookie(pParse->db, v, iDb);
exit_begin_add_column:
sqlite3SrcListDelete(pSrc);
return;
}
/*
** This function is called after an "ALTER TABLE ... ADD" statement
** has been parsed. Argument pColDef contains the text of the new
** column definition.
**
** The Table structure pParse->pNewTable was extended to include
** the new column during parsing.
*/
void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
Table *pNew; /* Copy of pParse->pNewTable */
Table *pTab; /* Table being altered */
int iDb; /* Database number */
const char *zDb; /* Database name */
const char *zTab; /* Table name */
char *zCol; /* Null-terminated column definition */
Column *pCol; /* The new column */
Expr *pDflt; /* Default value for the new column */
if( pParse->nErr ) return;
pNew = pParse->pNewTable;
assert( pNew );
iDb = sqlite3SchemaToIndex(pParse->db, pNew->pSchema);
zDb = pParse->db->aDb[iDb].zName;
zTab = pNew->zName;
pCol = &pNew->aCol[pNew->nCol-1];
pDflt = pCol->pDflt;
pTab = sqlite3FindTable(pParse->db, zTab, zDb);
assert( pTab );
#ifndef SQLITE_OMIT_AUTHORIZATION
/* Invoke the authorization callback. */
if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){
return;
}
#endif
/* If the default value for the new column was specified with a
** literal NULL, then set pDflt to 0. This simplifies checking
** for an SQL NULL default below.
*/
if( pDflt && pDflt->op==TK_NULL ){
pDflt = 0;
}
/* Check that the new column is not specified as PRIMARY KEY or UNIQUE.
** If there is a NOT NULL constraint, then the default value for the
** column must not be NULL.
*/
if( pCol->isPrimKey ){
sqlite3ErrorMsg(pParse, "Cannot add a PRIMARY KEY column");
return;
}
if( pNew->pIndex ){
sqlite3ErrorMsg(pParse, "Cannot add a UNIQUE column");
return;
}
if( pCol->notNull && !pDflt ){
sqlite3ErrorMsg(pParse,
"Cannot add a NOT NULL column with default value NULL");
return;
}
/* Ensure the default expression is something that sqlite3ValueFromExpr()
** can handle (i.e. not CURRENT_TIME etc.)
*/
if( pDflt ){
sqlite3_value *pVal;
if( sqlite3ValueFromExpr(pDflt, SQLITE_UTF8, SQLITE_AFF_NONE, &pVal) ){
/* malloc() has failed */
return;
}
if( !pVal ){
sqlite3ErrorMsg(pParse, "Cannot add a column with non-constant default");
return;
}
sqlite3ValueFree(pVal);
}
/* Modify the CREATE TABLE statement. */
zCol = sqliteStrNDup((char*)pColDef->z, pColDef->n);
if( zCol ){
char *zEnd = &zCol[pColDef->n-1];
while( (zEnd>zCol && *zEnd==';') || isspace(*(unsigned char *)zEnd) ){
*zEnd-- = '\0';
}
sqlite3NestedParse(pParse,
"UPDATE %Q.%s SET "
"sql = substr(sql,1,%d) || ', ' || %Q || substr(sql,%d,length(sql)) "
"WHERE type = 'table' AND name = %Q",
zDb, SCHEMA_TABLE(iDb), pNew->addColOffset, zCol, pNew->addColOffset+1,
zTab
);
sqliteFree(zCol);
}
/* If the default value of the new column is NULL, then set the file
** format to 2. If the default value of the new column is not NULL,
** the file format becomes 3.
*/
sqlite3MinimumFileFormat(pParse, iDb, pDflt ? 3 : 2);
/* Reload the schema of the modified table. */
reloadTableSchema(pParse, pTab, pTab->zName);
}
/*
** Generate code to implement the "ALTER TABLE xxx RENAME TO yyy"
** command.
*/
void sqlite3AlterRenameTable(
Parse *pParse, /* Parser context. */
SrcList *pSrc, /* The table to rename. */
Token *pName /* The new table name. */
){
int iDb; /* Database that contains the table */
char *zDb; /* Name of database iDb */
Table *pTab; /* Table being renamed */
char *zName = 0; /* NULL-terminated version of pName */
sqlite3 *db = pParse->db; /* Database connection */
Vdbe *v;
#ifndef SQLITE_OMIT_TRIGGER
char *zWhere = 0; /* Where clause to locate temp triggers */
#endif
if( sqlite3MallocFailed() ) goto exit_rename_table;
assert( pSrc->nSrc==1 );
pTab = sqlite3LocateTable(pParse, pSrc->a[0].zName, pSrc->a[0].zDatabase);
if( !pTab ) goto exit_rename_table;
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( IsVirtual(pTab) ){
sqlite3ErrorMsg(pParse, "virtual tables may not be altered");
goto exit_rename_table;
}
#endif
iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
zDb = db->aDb[iDb].zName;
/* Get a NULL terminated version of the new table name. */
zName = sqlite3NameFromToken(pName);
if( !zName ) goto exit_rename_table;
/* Check that a table or index named 'zName' does not already exist
** in database iDb. If so, this is an error.
*/
if( sqlite3FindTable(db, zName, zDb) || sqlite3FindIndex(db, zName, zDb) ){
sqlite3ErrorMsg(pParse,
"there is already another table or index with this name: %s", zName);
goto exit_rename_table;
}
/* Make sure it is not a system table being altered, or a reserved name
** that the table is being renamed to.
*/
if( strlen(pTab->zName)>6 && 0==sqlite3StrNICmp(pTab->zName, "sqlite_", 7) ){
sqlite3ErrorMsg(pParse, "table %s may not be altered", pTab->zName);
goto exit_rename_table;
}
if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
goto exit_rename_table;
}
#ifndef SQLITE_OMIT_AUTHORIZATION
/* Invoke the authorization callback. */
if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){
goto exit_rename_table;
}
#endif
/* Begin a transaction and code the VerifyCookie for database iDb.
** Then modify the schema cookie (since the ALTER TABLE modifies the
** schema).
*/
v = sqlite3GetVdbe(pParse);
if( v==0 ){
goto exit_rename_table;
}
sqlite3BeginWriteOperation(pParse, 0, iDb);
sqlite3ChangeCookie(db, v, iDb);
/* Modify the sqlite_master table to use the new table name. */
sqlite3NestedParse(pParse,
"UPDATE %Q.%s SET "
#ifdef SQLITE_OMIT_TRIGGER
"sql = sqlite_rename_table(sql, %Q), "
#else
"sql = CASE "
"WHEN type = 'trigger' THEN sqlite_rename_trigger(sql, %Q)"
"ELSE sqlite_rename_table(sql, %Q) END, "
#endif
"tbl_name = %Q, "
"name = CASE "
"WHEN type='table' THEN %Q "
"WHEN name LIKE 'sqlite_autoindex%%' AND type='index' THEN "
"'sqlite_autoindex_' || %Q || substr(name, %d+18,10) "
"ELSE name END "
"WHERE tbl_name=%Q AND "
"(type='table' OR type='index' OR type='trigger');",
zDb, SCHEMA_TABLE(iDb), zName, zName, zName,
#ifndef SQLITE_OMIT_TRIGGER
zName,
#endif
zName, strlen(pTab->zName), pTab->zName
);
#ifndef SQLITE_OMIT_AUTOINCREMENT
/* If the sqlite_sequence table exists in this database, then update
** it with the new table name.
*/
if( sqlite3FindTable(db, "sqlite_sequence", zDb) ){
sqlite3NestedParse(pParse,
"UPDATE %Q.sqlite_sequence set name = %Q WHERE name = %Q",
zDb, zName, pTab->zName);
}
#endif
#ifndef SQLITE_OMIT_TRIGGER
/* If there are TEMP triggers on this table, modify the sqlite_temp_master
** table. Don't do this if the table being ALTERed is itself located in
** the temp database.
*/
if( (zWhere=whereTempTriggers(pParse, pTab))!=0 ){
sqlite3NestedParse(pParse,
"UPDATE sqlite_temp_master SET "
"sql = sqlite_rename_trigger(sql, %Q), "
"tbl_name = %Q "
"WHERE %s;", zName, zName, zWhere);
sqliteFree(zWhere);
}
#endif
/* Drop and reload the internal table schema. */
reloadTableSchema(pParse, pTab, zName);
exit_rename_table:
sqlite3SrcListDelete(pSrc);
sqliteFree(zName);
}
/*
** Analyze the ORDER BY clause in a compound SELECT statement. Modify
** each term of the ORDER BY clause is a constant integer between 1
** and N where N is the number of columns in the compound SELECT.
**
** ORDER BY terms that are already an integer between 1 and N are
** unmodified. ORDER BY terms that are integers outside the range of
** 1 through N generate an error. ORDER BY terms that are expressions
** are matched against result set expressions of compound SELECT
** beginning with the left-most SELECT and working toward the right.
** At the first match, the ORDER BY expression is transformed into
** the integer column number.
**
** Return the number of errors seen.
*/
static int resolveCompoundOrderBy(
Parse *pParse, /* Parsing context. Leave error messages here */
Select *pSelect /* The SELECT statement containing the ORDER BY */
){
int i;
ExprList *pOrderBy;
ExprList *pEList;
sqlite3 *db;
int moreToDo = 1;
pOrderBy = pSelect->pOrderBy;
if( pOrderBy==0 ) return 0;
db = pParse->db;
#if SQLITE_MAX_COLUMN
if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
sqlite3ErrorMsg(pParse, "too many terms in ORDER BY clause");
return 1;
}
#endif
for(i=0; i<pOrderBy->nExpr; i++){
pOrderBy->a[i].done = 0;
}
pSelect->pNext = 0;
while( pSelect->pPrior ){
pSelect->pPrior->pNext = pSelect;
pSelect = pSelect->pPrior;
}
while( pSelect && moreToDo ){
struct ExprList_item *pItem;
moreToDo = 0;
pEList = pSelect->pEList;
assert( pEList!=0 );
for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){
int iCol = -1;
Expr *pE, *pDup;
if( pItem->done ) continue;
pE = sqlite3ExprSkipCollate(pItem->pExpr);
if( sqlite3ExprIsInteger(pE, &iCol) ){
if( iCol<=0 || iCol>pEList->nExpr ){
resolveOutOfRangeError(pParse, "ORDER", i+1, pEList->nExpr);
return 1;
}
}else{
iCol = resolveAsName(pParse, pEList, pE);
if( iCol==0 ){
pDup = sqlite3ExprDup(db, pE, 0);
if( !db->mallocFailed ){
assert(pDup);
iCol = resolveOrderByTermToExprList(pParse, pSelect, pDup);
}
sqlite3ExprDelete(db, pDup);
}
}
if( iCol>0 ){
/* Convert the ORDER BY term into an integer column number iCol,
** taking care to preserve the COLLATE clause if it exists */
Expr *pNew = sqlite3Expr(db, TK_INTEGER, 0);
if( pNew==0 ) return 1;
pNew->flags |= EP_IntValue;
pNew->u.iValue = iCol;
if( pItem->pExpr==pE ){
pItem->pExpr = pNew;
}else{
assert( pItem->pExpr->op==TK_COLLATE );
assert( pItem->pExpr->pLeft==pE );
pItem->pExpr->pLeft = pNew;
}
sqlite3ExprDelete(db, pE);
pItem->iOrderByCol = (u16)iCol;
pItem->done = 1;
}else{
moreToDo = 1;
}
}
pSelect = pSelect->pNext;
}
for(i=0; i<pOrderBy->nExpr; i++){
if( pOrderBy->a[i].done==0 ){
sqlite3ErrorMsg(pParse, "%r ORDER BY term does not match any "
"column in the result set", i+1);
return 1;
}
}
return 0;
}
/*
** Write an error message into pParse->zErrMsg that explains that the
** user-supplied authorization function returned an illegal value.
*/
static void sqliteAuthBadReturnCode(Parse *pParse, int rc){
sqlite3ErrorMsg(pParse, "illegal return value (%d) from the "
"authorization function - should be SQLITE_OK, SQLITE_IGNORE, "
"or SQLITE_DENY", rc);
pParse->rc = SQLITE_ERROR;
}
/*
** Resolve names in the SELECT statement p and all of its descendents.
*/
static int resolveSelectStep(Walker *pWalker, Select *p){
NameContext *pOuterNC; /* Context that contains this SELECT */
NameContext sNC; /* Name context of this SELECT */
int isCompound; /* True if p is a compound select */
int nCompound; /* Number of compound terms processed so far */
Parse *pParse; /* Parsing context */
ExprList *pEList; /* Result set expression list */
int i; /* Loop counter */
ExprList *pGroupBy; /* The GROUP BY clause */
Select *pLeftmost; /* Left-most of SELECT of a compound */
sqlite3 *db; /* Database connection */
assert( p!=0 );
if( p->selFlags & SF_Resolved ){
return WRC_Prune;
}
pOuterNC = pWalker->u.pNC;
pParse = pWalker->pParse;
db = pParse->db;
/* Normally sqlite3SelectExpand() will be called first and will have
** already expanded this SELECT. However, if this is a subquery within
** an expression, sqlite3ResolveExprNames() will be called without a
** prior call to sqlite3SelectExpand(). When that happens, let
** sqlite3SelectPrep() do all of the processing for this SELECT.
** sqlite3SelectPrep() will invoke both sqlite3SelectExpand() and
** this routine in the correct order.
*/
if( (p->selFlags & SF_Expanded)==0 ){
sqlite3SelectPrep(pParse, p, pOuterNC);
return (pParse->nErr || db->mallocFailed) ? WRC_Abort : WRC_Prune;
}
isCompound = p->pPrior!=0;
nCompound = 0;
pLeftmost = p;
while( p ){
assert( (p->selFlags & SF_Expanded)!=0 );
assert( (p->selFlags & SF_Resolved)==0 );
p->selFlags |= SF_Resolved;
/* Resolve the expressions in the LIMIT and OFFSET clauses. These
** are not allowed to refer to any names, so pass an empty NameContext.
*/
memset(&sNC, 0, sizeof(sNC));
sNC.pParse = pParse;
if( sqlite3ResolveExprNames(&sNC, p->pLimit) ||
sqlite3ResolveExprNames(&sNC, p->pOffset) ){
return WRC_Abort;
}
/* Set up the local name-context to pass to sqlite3ResolveExprNames() to
** resolve the result-set expression list.
*/
sNC.ncFlags = NC_AllowAgg;
sNC.pSrcList = p->pSrc;
sNC.pNext = pOuterNC;
/* Resolve names in the result set. */
pEList = p->pEList;
assert( pEList!=0 );
for(i=0; i<pEList->nExpr; i++){
Expr *pX = pEList->a[i].pExpr;
if( sqlite3ResolveExprNames(&sNC, pX) ){
return WRC_Abort;
}
}
/* Recursively resolve names in all subqueries
*/
for(i=0; i<p->pSrc->nSrc; i++){
struct SrcList_item *pItem = &p->pSrc->a[i];
if( pItem->pSelect ){
NameContext *pNC; /* Used to iterate name contexts */
int nRef = 0; /* Refcount for pOuterNC and outer contexts */
const char *zSavedContext = pParse->zAuthContext;
/* Count the total number of references to pOuterNC and all of its
** parent contexts. After resolving references to expressions in
** pItem->pSelect, check if this value has changed. If so, then
** SELECT statement pItem->pSelect must be correlated. Set the
** pItem->isCorrelated flag if this is the case. */
for(pNC=pOuterNC; pNC; pNC=pNC->pNext) nRef += pNC->nRef;
if( pItem->zName ) pParse->zAuthContext = pItem->zName;
sqlite3ResolveSelectNames(pParse, pItem->pSelect, pOuterNC);
pParse->zAuthContext = zSavedContext;
if( pParse->nErr || db->mallocFailed ) return WRC_Abort;
for(pNC=pOuterNC; pNC; pNC=pNC->pNext) nRef -= pNC->nRef;
assert( pItem->isCorrelated==0 && nRef<=0 );
pItem->isCorrelated = (nRef!=0);
}
}
/* If there are no aggregate functions in the result-set, and no GROUP BY
** expression, do not allow aggregates in any of the other expressions.
*/
assert( (p->selFlags & SF_Aggregate)==0 );
pGroupBy = p->pGroupBy;
if( pGroupBy || (sNC.ncFlags & NC_HasAgg)!=0 ){
p->selFlags |= SF_Aggregate;
}else{
sNC.ncFlags &= ~NC_AllowAgg;
}
/* If a HAVING clause is present, then there must be a GROUP BY clause.
*/
if( p->pHaving && !pGroupBy ){
sqlite3ErrorMsg(pParse, "a GROUP BY clause is required before HAVING");
return WRC_Abort;
}
/* Add the expression list to the name-context before parsing the
** other expressions in the SELECT statement. This is so that
** expressions in the WHERE clause (etc.) can refer to expressions by
** aliases in the result set.
**
** Minor point: If this is the case, then the expression will be
** re-evaluated for each reference to it.
*/
sNC.pEList = p->pEList;
if( sqlite3ResolveExprNames(&sNC, p->pWhere) ||
sqlite3ResolveExprNames(&sNC, p->pHaving)
){
return WRC_Abort;
}
/* The ORDER BY and GROUP BY clauses may not refer to terms in
** outer queries
*/
sNC.pNext = 0;
sNC.ncFlags |= NC_AllowAgg;
/* Process the ORDER BY clause for singleton SELECT statements.
** The ORDER BY clause for compounds SELECT statements is handled
** below, after all of the result-sets for all of the elements of
** the compound have been resolved.
*/
if( !isCompound && resolveOrderGroupBy(&sNC, p, p->pOrderBy, "ORDER") ){
return WRC_Abort;
}
if( db->mallocFailed ){
return WRC_Abort;
}
/* Resolve the GROUP BY clause. At the same time, make sure
** the GROUP BY clause does not contain aggregate functions.
*/
if( pGroupBy ){
struct ExprList_item *pItem;
if( resolveOrderGroupBy(&sNC, p, pGroupBy, "GROUP") || db->mallocFailed ){
return WRC_Abort;
}
for(i=0, pItem=pGroupBy->a; i<pGroupBy->nExpr; i++, pItem++){
if( ExprHasProperty(pItem->pExpr, EP_Agg) ){
sqlite3ErrorMsg(pParse, "aggregate functions are not allowed in "
"the GROUP BY clause");
return WRC_Abort;
}
}
}
/* Advance to the next term of the compound
*/
p = p->pPrior;
nCompound++;
}
/* Resolve the ORDER BY on a compound SELECT after all terms of
** the compound have been resolved.
*/
if( isCompound && resolveCompoundOrderBy(pParse, pLeftmost) ){
return WRC_Abort;
}
return WRC_Prune;
}
/*
** Generate code to implement the "ALTER TABLE xxx RENAME TO yyy"
** command. 生成代码来实现“ALTER TABLE xxx重命名yyy”命令。
*/
void sqlite3AlterRenameTable(
Parse *pParse, /* Parser context. 语法分析器上下文*/
SrcList *pSrc, /* The table to rename. 重命名的表*/
Token *pName /* The new table name. 新表名*/
){
int iDb; /* Database that contains the table 包含表的数据库*/
char *zDb; /* Name of database iDb 数据库iDb 的名称*/
Table *pTab; /* Table being renamed 正在重命名的表*/
char *zName = 0; /* NULL-terminated version of pName pName的空值终止版本*/
sqlite3 *db = pParse->db; /* Database connection 数据库的连接*/
int nTabName; /* Number of UTF-8 characters in zTabName 在 zTabName里的UTF-8类型的数目*/
const char *zTabName; /* Original name of the table 最初的数据库名称*/
Vdbe *v;
#ifndef SQLITE_OMIT_TRIGGER
char *zWhere = 0; /* Where clause to locate temp triggers Where 子句位于temp触发器*/
#endif
VTable *pVTab = 0; /* Non-zero if this is a v-tab with an xRename() 如果是 一个v-tab 和一个xRename() ，则为零*/
int savedDbFlags; /* Saved value of db->flags db->flags的保留值*/
savedDbFlags = db->flags;
if( NEVER(db->mallocFailed) ) goto exit_rename_table;
assert( pSrc->nSrc==1 );
assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );
pTab = sqlite3LocateTable(pParse, 0, pSrc->a[0].zName, pSrc->a[0].zDatabase);
if( !pTab ) goto exit_rename_table;
iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
zDb = db->aDb[iDb].zName;
db->flags |= SQLITE_PreferBuiltin;
/* Get a NULL terminated version of the new table name. 得到一个空终止版本的新表的名称。*/
zName = sqlite3NameFromToken(db, pName);
if( !zName ) goto exit_rename_table;
/* Check that a table or index named 'zName' does not already exist
** in database iDb. If so, this is an error.检查一个表或索引名叫“zName”不存在数据库iDb。
如果是这样,这是一个错误。
*/
if( sqlite3FindTable(db, zName, zDb) || sqlite3FindIndex(db, zName, zDb) ){
sqlite3ErrorMsg(pParse,
"there is already another table or index with this name: %s", zName);
goto exit_rename_table;
}
/* Make sure it is not a system table being altered, or a reserved name
** that the table is being renamed to.
确保它不是一个正在被修改的系统表或者一个正在被重命名的保留的名称表
*/
if( SQLITE_OK!=isSystemTable(pParse, pTab->zName) ){
goto exit_rename_table;
}
if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){ goto
exit_rename_table;
}
#ifndef SQLITE_OMIT_VIEW
if( pTab->pSelect ){
sqlite3ErrorMsg(pParse, "view %s may not be altered", pTab->zName);
goto exit_rename_table;
}
#endif
#ifndef SQLITE_OMIT_AUTHORIZATION
/* Invoke the authorization callback. 调用授权回调。*/
if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){
goto exit_rename_table;
}
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( sqlite3ViewGetColumnNames(pParse, pTab) ){
goto exit_rename_table;
}
if( IsVirtual(pTab) ){
pVTab = sqlite3GetVTable(db, pTab);
if( pVTab->pVtab->pModule->xRename==0 ){
pVTab = 0;
}
}
#endif
/* Begin a transaction and code the VerifyCookie for database iDb.
** Then modify the schema cookie (since the ALTER TABLE modifies the
** schema). Open a statement transaction if the table is a virtual
** table.
对于iDb数据库开始一个事务和代码的VerifyCookie。
然后修改模式cookie(因为ALTER TABLE修改模式)。
如果表是一个虚拟表打开一个声明事务。
*/
v = sqlite3GetVdbe(pParse);
if( v==0 ){
goto exit_rename_table;
}
sqlite3BeginWriteOperation(pParse, pVTab!=0, iDb);
sqlite3ChangeCookie(pParse, iDb);
/* If this is a virtual table, invoke the xRename() function if
** one is defined. The xRename() callback will modify the names
** of any resources used by the v-table implementation (including other
** SQLite tables) that are identified by the name of the virtual table.、
如果这是一个虚拟表,调用xRename()函数如果一个定义。
xRename()回调将修改使用v-table实现的任何资源的名字(包括其他SQLite表)，
这个v-table实现是确定的虚拟表的名称。
*/
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( pVTab ){
int i = ++pParse->nMem;
sqlite3VdbeAddOp4(v, OP_String8, 0, i, 0, zName, 0);
sqlite3VdbeAddOp4(v, OP_VRename, i, 0, 0,(const char*)pVTab, P4_VTAB);
sqlite3MayAbort(pParse);
}
#endif
/* figure out how many UTF-8 characters are in zName 算出在zName里有多少utf - 8字符*/
zTabName = pTab->zName;
nTabName = sqlite3Utf8CharLen(zTabName, -1);
#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
if( db->flags&SQLITE_ForeignKeys ){
/* If foreign-key support is enabled, rewrite the CREATE TABLE
** statements corresponding to all child tables of foreign key constraints
** for which the renamed table is the parent table.
如果启用了外键的支持,重写CREATE TABLE语句对应的所有子表的外键约束重命名表的父表。*/
if( (zWhere=whereForeignKeys(pParse, pTab))!=0 ){
sqlite3NestedParse(pParse,
"UPDATE \"%w\".%s SET "
"sql = sqlite_rename_parent(sql, %Q, %Q) "
"WHERE %s;", zDb, SCHEMA_TABLE(iDb), zTabName, zName, zWhere);
sqlite3DbFree(db, zWhere);
}
}
#endif
/* Modify the sqlite_master table to use the new table name. 修改sqlite_master表来使用新的表名。*/
sqlite3NestedParse(pParse,
"UPDATE %Q.%s SET "
#ifdef SQLITE_OMIT_TRIGGER
"sql = sqlite_rename_table(sql, %Q), "
#else
"sql = CASE "
"WHEN type = 'trigger' THEN sqlite_rename_trigger(sql, %Q)"
"ELSE sqlite_rename_table(sql, %Q) END, "
#endif
"tbl_name = %Q, "
"name = CASE "
"WHEN type='table' THEN %Q "
"WHEN name LIKE 'sqlite_autoindex%%' AND type='index' THEN "
"'sqlite_autoindex_' || %Q || substr(name,%d+18) "
"ELSE name END "
"WHERE tbl_name=%Q COLLATE nocase AND "
"(type='table' OR type='index' OR type='trigger');",
zDb, SCHEMA_TABLE(iDb), zName, zName, zName,
#ifndef SQLITE_OMIT_TRIGGER
zName,
#endif
zName, nTabName, zTabName
);
#ifndef SQLITE_OMIT_AUTOINCREMENT
/* If the sqlite_sequence table exists in this database, then update
** it with the new table name.
如果sqlite_sequence表存在于这个数据库中,那么用新表的名称更新它
*/
if( sqlite3FindTable(db, "sqlite_sequence", zDb) ){
sqlite3NestedParse(pParse,
"UPDATE \"%w\".sqlite_sequence set name = %Q WHERE name = %Q",
zDb, zName, pTab->zName);
}
#endif
#ifndef SQLITE_OMIT_TRIGGER
/* If there are TEMP triggers on this table, modify the sqlite_temp_master
** table. Don't do this if the table being ALTERed is itself located in
** the temp database.
如果在这个表上有临时触发器，修改sqlite_temp_master表，
如果表被修改本身就是位于临时数据库，不要做这些。
*/
if( (zWhere=whereTempTriggers(pParse, pTab))!=0 ){
sqlite3NestedParse(pParse,
"UPDATE sqlite_temp_master SET "
"sql = sqlite_rename_trigger(sql, %Q), "
"tbl_name = %Q "
"WHERE %s;", zName, zName, zWhere);
sqlite3DbFree(db, zWhere);
}
#endif
#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
if( db->flags&SQLITE_ForeignKeys ){
FKey *p;
for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){
Table *pFrom = p->pFrom;
if( pFrom!=pTab ){
reloadTableSchema(pParse, p->pFrom, pFrom->zName);
}
}
}
#endif
/* Drop and reload the internal table schema. 删除和重新加载内部表模式。*/
reloadTableSchema(pParse, pTab, zName);
exit_rename_table:
sqlite3SrcListDelete(db, pSrc);
sqlite3DbFree(db, zName);
db->flags = savedDbFlags;
}
/*
** This is called by the parser when it sees a CREATE TRIGGER statement
** up to the point of the BEGIN before the trigger actions. A Trigger
** structure is generated based on the information available and stored
** in pParse->pNewTrigger. After the trigger actions have been parsed, the
** sqlite3FinishTrigger() function is called to complete the trigger
** construction process.
*/
void sqlite3BeginTrigger(
Parse *pParse, /* The parse context of the CREATE TRIGGER statement */
Token *pName1, /* The name of the trigger */
Token *pName2, /* The name of the trigger */
int tr_tm, /* One of TK_BEFORE, TK_AFTER, TK_INSTEAD */
int op, /* One of TK_INSERT, TK_UPDATE, TK_DELETE */
IdList *pColumns, /* column list if this is an UPDATE OF trigger */
SrcList *pTableName,/* The name of the table/view the trigger applies to */
Expr *pWhen, /* WHEN clause */
int isTemp, /* True if the TEMPORARY keyword is present */
int noErr /* Suppress errors if the trigger already exists */
) {
Trigger *pTrigger = 0; /* The new trigger */
Table *pTab; /* Table that the trigger fires off of */
char *zName = 0; /* Name of the trigger */
sqlite3 *db = pParse->db; /* The database connection */
int iDb; /* The database to store the trigger in */
Token *pName; /* The unqualified db name */
DbFixer sFix; /* State vector for the DB fixer */
int iTabDb; /* Index of the database holding pTab */
assert( pName1!=0 ); /* pName1->z might be NULL, but not pName1 itself */
assert( pName2!=0 );
assert( op==TK_INSERT || op==TK_UPDATE || op==TK_DELETE );
assert( op>0 && op<0xff );
if( isTemp ) {
/* If TEMP was specified, then the trigger name may not be qualified. */
if( pName2->n>0 ) {
sqlite3ErrorMsg(pParse, "temporary trigger may not have qualified name");
goto trigger_cleanup;
}
iDb = 1;
pName = pName1;
} else {
/* Figure out the db that the the trigger will be created in */
iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
if( iDb<0 ) {
goto trigger_cleanup;
}
}
/* If the trigger name was unqualified, and the table is a temp table,
** then set iDb to 1 to create the trigger in the temporary database.
** If sqlite3SrcListLookup() returns 0, indicating the table does not
** exist, the error is caught by the block below.
*/
if( !pTableName || db->mallocFailed ) {
goto trigger_cleanup;
}
pTab = sqlite3SrcListLookup(pParse, pTableName);
if( db->init.busy==0 && pName2->n==0 && pTab
&& pTab->pSchema==db->aDb[1].pSchema ) {
iDb = 1;
}
/* Ensure the table name matches database name and that the table exists */
if( db->mallocFailed ) goto trigger_cleanup;
assert( pTableName->nSrc==1 );
if( sqlite3FixInit(&sFix, pParse, iDb, "trigger", pName) &&
sqlite3FixSrcList(&sFix, pTableName) ) {
goto trigger_cleanup;
}
pTab = sqlite3SrcListLookup(pParse, pTableName);
if( !pTab ) {
/* The table does not exist. */
if( db->init.iDb==1 ) {
/* Ticket #3810.
** Normally, whenever a table is dropped, all associated triggers are
** dropped too. But if a TEMP trigger is created on a non-TEMP table
** and the table is dropped by a different database connection, the
** trigger is not visible to the database connection that does the
** drop so the trigger cannot be dropped. This results in an
** "orphaned trigger" - a trigger whose associated table is missing.
*/
db->init.orphanTrigger = 1;
}
goto trigger_cleanup;
}
if( IsVirtual(pTab) ) {
sqlite3ErrorMsg(pParse, "cannot create triggers on virtual tables");
goto trigger_cleanup;
}
/* Check that the trigger name is not reserved and that no trigger of the
** specified name exists */
zName = sqlite3NameFromToken(db, pName);
if( !zName || SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ) {
goto trigger_cleanup;
}
if( sqlite3HashFind(&(db->aDb[iDb].pSchema->trigHash),
zName, sqlite3Strlen30(zName)) ) {
if( !noErr ) {
sqlite3ErrorMsg(pParse, "trigger %T already exists", pName);
}
goto trigger_cleanup;
}
/* Do not create a trigger on a system table */
if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 ) {
sqlite3ErrorMsg(pParse, "cannot create trigger on system table");
pParse->nErr++;
goto trigger_cleanup;
}
/* INSTEAD of triggers are only for views and views only support INSTEAD
** of triggers.
*/
if( pTab->pSelect && tr_tm!=TK_INSTEAD ) {
sqlite3ErrorMsg(pParse, "cannot create %s trigger on view: %S",
(tr_tm == TK_BEFORE)?"BEFORE":"AFTER", pTableName, 0);
goto trigger_cleanup;
}
if( !pTab->pSelect && tr_tm==TK_INSTEAD ) {
sqlite3ErrorMsg(pParse, "cannot create INSTEAD OF"
" trigger on table: %S", pTableName, 0);
goto trigger_cleanup;
}
iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int code = SQLITE_CREATE_TRIGGER;
const char *zDb = db->aDb[iTabDb].zName;
const char *zDbTrig = isTemp ? db->aDb[1].zName : zDb;
if( iTabDb==1 || isTemp ) code = SQLITE_CREATE_TEMP_TRIGGER;
if( sqlite3AuthCheck(pParse, code, zName, pTab->zName, zDbTrig) ) {
goto trigger_cleanup;
}
if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(iTabDb),0,zDb)) {
goto trigger_cleanup;
}
}
#endif
/* INSTEAD OF triggers can only appear on views and BEFORE triggers
** cannot appear on views. So we might as well translate every
** INSTEAD OF trigger into a BEFORE trigger. It simplifies code
** elsewhere.
*/
if (tr_tm == TK_INSTEAD) {
tr_tm = TK_BEFORE;
}
/* Build the Trigger object */
pTrigger = (Trigger*)sqlite3DbMallocZero(db, sizeof(Trigger));
if( pTrigger==0 ) goto trigger_cleanup;
pTrigger->zName = zName;
zName = 0;
pTrigger->table = sqlite3DbStrDup(db, pTableName->a[0].zName);
pTrigger->pSchema = db->aDb[iDb].pSchema;
pTrigger->pTabSchema = pTab->pSchema;
pTrigger->op = (u8)op;
pTrigger->tr_tm = tr_tm==TK_BEFORE ? TRIGGER_BEFORE : TRIGGER_AFTER;
pTrigger->pWhen = sqlite3ExprDup(db, pWhen, EXPRDUP_REDUCE);
pTrigger->pColumns = sqlite3IdListDup(db, pColumns);
assert( pParse->pNewTrigger==0 );
pParse->pNewTrigger = pTrigger;
trigger_cleanup:
sqlite3DbFree(db, zName);
sqlite3SrcListDelete(db, pTableName);
sqlite3IdListDelete(db, pColumns);
sqlite3ExprDelete(db, pWhen);
if( !pParse->pNewTrigger ) {
sqlite3DeleteTrigger(db, pTrigger);
} else {
assert( pParse->pNewTrigger==pTrigger );
}
}
/*
** This function is called after an "ALTER TABLE ... ADD" statement
** has been parsed. Argument pColDef contains the text of the new
** column definition.
**
** The Table structure pParse->pNewTable was extended to include
** the new column during parsing.
在“ALTER TABLE…添加“声明解析后这个函数被调用。
参数pColDef包含新列定义的文本。
表结构pParse - > pNewTable扩大到包括在解析新列。
*/
void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
Table *pNew; /* Copy of pParse->pNewTable pParse->pNew表的副本*/
Table *pTab; /* Table being altered 被修改的表*/
int iDb; /* Database number 数据库数*/
const char *zDb; /* Database name 数据库名*/
const char *zTab; /* Table name 表名*/
char *zCol; /* Null-terminated column definition 空值终止列定义*/
Column *pCol; /* The new column 新列*/
Expr *pDflt; /* Default value for the new column 为新列默认数值*/
sqlite3 *db; /* The database connection; 数据库的连接*/
db = pParse->db;
if( pParse->nErr || db->mallocFailed ) return;
pNew = pParse->pNewTable;
assert( pNew );
assert( sqlite3BtreeHoldsAllMutexes(db) );
iDb = sqlite3SchemaToIndex(db, pNew->pSchema);
zDb = db->aDb[iDb].zName;
zTab = &pNew->zName[16]; /* Skip the "sqlite_altertab_" prefix on the name 跳过“sqlite_altertab_”前缀的名称*/
pCol = &pNew->aCol[pNew->nCol-1];
pDflt = pCol->pDflt;
pTab = sqlite3FindTable(db, zTab, zDb);
assert( pTab );
#ifndef SQLITE_OMIT_AUTHORIZATION
/* Invoke the authorization callback. 调用授权回调*/
if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){
return;
}
#endif
/* If the default value for the new column was specified with a
** literal NULL, then set pDflt to 0. This simplifies checking
** for an SQL NULL default below.
如果新列的默认值是用文字指定NULL,那么pDflt设置为0。
这简化了检查SQL空下面的默认。
*/
if( pDflt && pDflt->op==TK_NULL ){
pDflt = 0;
}
/* Check that the new column is not specified as PRIMARY KEY or UNIQUE.
** If there is a NOT NULL constraint, then the default value for the
** column must not be NULL.
检查新列没有指定主键或唯一的。
如果有一个非空约束,然后列的默认值不能为空。
*/
if( pCol->isPrimKey ){
sqlite3ErrorMsg(pParse, "Cannot add a PRIMARY KEY column");
return;
}
if( pNew->pIndex ){
sqlite3ErrorMsg(pParse, "Cannot add a UNIQUE column");
return;
}
if( (db->flags&SQLITE_ForeignKeys) && pNew->pFKey && pDflt ){
sqlite3ErrorMsg(pParse,
"Cannot add a REFERENCES column with non-NULL default value");
return;
}
if( pCol->notNull && !pDflt ){
sqlite3ErrorMsg(pParse,
"Cannot add a NOT NULL column with default value NULL");
return;
}
/* Ensure the default expression is something that sqlite3ValueFromExpr()
** can handle (i.e. not CURRENT_TIME etc.)
确保默认表达式是sqlite3ValueFromExpr()可以处理的事(即不是当前时间等。)
*/
if( pDflt ){
sqlite3_value *pVal;
if( sqlite3ValueFromExpr(db, pDflt, SQLITE_UTF8, SQLITE_AFF_NONE, &pVal) ){
db->mallocFailed = 1;
return;
}
if( !pVal ){
sqlite3ErrorMsg(pParse, "Cannot add a column with non-constant default");
return;
}
sqlite3ValueFree(pVal);
}
/* Modify the CREATE TABLE statement. 修改CREATE TABLE语句。*/
zCol = sqlite3DbStrNDup(db, (char*)pColDef->z, pColDef->n);
if( zCol ){
char *zEnd = &zCol[pColDef->n-1];
int savedDbFlags = db->flags;
while( zEnd>zCol && (*zEnd==';' || sqlite3Isspace(*zEnd)) ){
*zEnd-- = '\0';
}
db->flags |= SQLITE_PreferBuiltin;
sqlite3NestedParse(pParse,
"UPDATE \"%w\".%s SET "
"sql = substr(sql,1,%d) || ', ' || %Q || substr(sql,%d) "
"WHERE type = 'table' AND name = %Q",
zDb, SCHEMA_TABLE(iDb), pNew->addColOffset, zCol, pNew->addColOffset+1,
zTab
);
sqlite3DbFree(db, zCol);
db->flags = savedDbFlags;
}
/* If the default value of the new column is NULL, then set the file
** format to 2. If the default value of the new column is not NULL,
** the file format becomes 3.
如果新列的默认值为空,那么将文件格式设置为2。如果新列的默认值不为空,文件格式变成3。
*/
sqlite3MinimumFileFormat(pParse, iDb, pDflt ? 3 : 2);
/* Reload the schema of the modified table. 重新加载修改后的表的模式。*/
reloadTableSchema(pParse, pTab, pTab->zName);
}
/*
** This routine is call to handle SQL of the following forms:
**
** insert into TABLE (IDLIST) values(EXPRLIST)
** insert into TABLE (IDLIST) select
**
** The IDLIST following the table name is always optional. If omitted,
** then a list of all columns for the table is substituted. The IDLIST
** appears in the pColumn parameter. pColumn is NULL if IDLIST is omitted.
**
** The pList parameter holds EXPRLIST in the first form of the INSERT
** statement above, and pSelect is NULL. For the second form, pList is
** NULL and pSelect is a pointer to the select statement used to generate
** data for the insert.
**
** The code generated follows one of three templates. For a simple
** select with data coming from a VALUES clause, the code executes
** once straight down through. The template looks like this:
**
** open write cursor to <table> and its indices
** puts VALUES clause expressions onto the stack
** write the resulting record into <table>
** cleanup
**
** If the statement is of the form
**
** INSERT INTO <table> SELECT ...
**
** And the SELECT clause does not read from <table> at any time, then
** the generated code follows this template:
**
** goto B
** A: setup for the SELECT
** loop over the tables in the SELECT
** gosub C
** end loop
** cleanup after the SELECT
** goto D
** B: open write cursor to <table> and its indices
** goto A
** C: insert the select result into <table>
** return
** D: cleanup
**
** The third template is used if the insert statement takes its
** values from a SELECT but the data is being inserted into a table
** that is also read as part of the SELECT. In the third form,
** we have to use a intermediate table to store the results of
** the select. The template is like this:
**
** goto B
** A: setup for the SELECT
** loop over the tables in the SELECT
** gosub C
** end loop
** cleanup after the SELECT
** goto D
** C: insert the select result into the intermediate table
** return
** B: open a cursor to an intermediate table
** goto A
** D: open write cursor to <table> and its indices
** loop over the intermediate table
** transfer values form intermediate table into <table>
** end the loop
** cleanup
*/
void sqlite3Insert(
Parse *pParse, /* Parser context */
SrcList *pTabList, /* Name of table into which we are inserting */
ExprList *pList, /* List of values to be inserted */
Select *pSelect, /* A SELECT statement to use as the data source */
IdList *pColumn, /* Column names corresponding to IDLIST. */
int onError /* How to handle constraint errors */
){
Table *pTab; /* The table to insert into */
char *zTab; /* Name of the table into which we are inserting */
const char *zDb; /* Name of the database holding this table */
int i, j, idx; /* Loop counters */
Vdbe *v; /* Generate code into this virtual machine */
Index *pIdx; /* For looping over indices of the table */
int nColumn; /* Number of columns in the data */
int base = 0; /* VDBE Cursor number for pTab */
int iCont=0,iBreak=0; /* Beginning and end of the loop over srcTab */
sqlite3 *db; /* The main database structure */
int keyColumn = -1; /* Column that is the INTEGER PRIMARY KEY */
int endOfLoop; /* Label for the end of the insertion loop */
int useTempTable = 0; /* Store SELECT results in intermediate table */
int srcTab = 0; /* Data comes from this temporary cursor if >=0 */
int iSelectLoop = 0; /* Address of code that implements the SELECT */
int iCleanup = 0; /* Address of the cleanup code */
int iInsertBlock = 0; /* Address of the subroutine used to insert data */
int iCntMem = 0; /* Memory cell used for the row counter */
int newIdx = -1; /* Cursor for the NEW table */
Db *pDb; /* The database containing table being inserted into */
int counterMem = 0; /* Memory cell holding AUTOINCREMENT counter */
#ifndef SQLITE_OMIT_TRIGGER
int isView; /* True if attempting to insert into a view */
int triggers_exist = 0; /* True if there are FOR EACH ROW triggers */
#endif
#ifndef SQLITE_OMIT_AUTOINCREMENT
int counterRowid; /* Memory cell holding rowid of autoinc counter */
#endif
if( pParse->nErr || sqlite3_malloc_failed ) goto insert_cleanup;
db = pParse->db;
/* Locate the table into which we will be inserting new information.
*/
assert( pTabList->nSrc==1 );
zTab = pTabList->a[0].zName;
if( zTab==0 ) goto insert_cleanup;
pTab = sqlite3SrcListLookup(pParse, pTabList);
if( pTab==0 ){
goto insert_cleanup;
}
assert( pTab->iDb<db->nDb );
pDb = &db->aDb[pTab->iDb];
zDb = pDb->zName;
if( sqlite3AuthCheck(pParse, SQLITE_INSERT, pTab->zName, 0, zDb) ){
goto insert_cleanup;
}
/* Figure out if we have any triggers and if the table being
** inserted into is a view
*/
#ifndef SQLITE_OMIT_TRIGGER
triggers_exist = sqlite3TriggersExist(pParse, pTab, TK_INSERT, 0);
isView = pTab->pSelect!=0;
#else
# define triggers_exist 0
# define isView 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif
/* Ensure that:
* (a) the table is not read-only,
* (b) that if it is a view then ON INSERT triggers exist
*/
if( sqlite3IsReadOnly(pParse, pTab, triggers_exist) ){
goto insert_cleanup;
}
if( pTab==0 ) goto insert_cleanup;
/* If pTab is really a view, make sure it has been initialized.
*/
if( isView && sqlite3ViewGetColumnNames(pParse, pTab) ){
goto insert_cleanup;
}
/* Ensure all required collation sequences are available. */
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
if( sqlite3CheckIndexCollSeq(pParse, pIdx) ){
goto insert_cleanup;
}
}
/* Allocate a VDBE
*/
v = sqlite3GetVdbe(pParse);
if( v==0 ) goto insert_cleanup;
if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
sqlite3BeginWriteOperation(pParse, pSelect || triggers_exist, pTab->iDb);
/* if there are row triggers, allocate a temp table for new.* references. */
if( triggers_exist ){
newIdx = pParse->nTab++;
}
#ifndef SQLITE_OMIT_AUTOINCREMENT
/* If this is an AUTOINCREMENT table, look up the sequence number in the
** sqlite_sequence table and store it in memory cell counterMem. Also
** remember the rowid of the sqlite_sequence table entry in memory cell
** counterRowid.
*/
if( pTab->autoInc ){
int iCur = pParse->nTab;
int base = sqlite3VdbeCurrentAddr(v);
counterRowid = pParse->nMem++;
counterMem = pParse->nMem++;
sqlite3VdbeAddOp(v, OP_Integer, pTab->iDb, 0);
sqlite3VdbeAddOp(v, OP_OpenRead, iCur, pDb->pSeqTab->tnum);
sqlite3VdbeAddOp(v, OP_SetNumColumns, iCur, 2);
sqlite3VdbeAddOp(v, OP_Rewind, iCur, base+13);
sqlite3VdbeAddOp(v, OP_Column, iCur, 0);
sqlite3VdbeOp3(v, OP_String8, 0, 0, pTab->zName, 0);
sqlite3VdbeAddOp(v, OP_Ne, 28417, base+12);
sqlite3VdbeAddOp(v, OP_Recno, iCur, 0);
sqlite3VdbeAddOp(v, OP_MemStore, counterRowid, 1);
sqlite3VdbeAddOp(v, OP_Column, iCur, 1);
sqlite3VdbeAddOp(v, OP_MemStore, counterMem, 1);
sqlite3VdbeAddOp(v, OP_Goto, 0, base+13);
sqlite3VdbeAddOp(v, OP_Next, iCur, base+4);
sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
}
#endif /* SQLITE_OMIT_AUTOINCREMENT */
/* Figure out how many columns of data are supplied. If the data
** is coming from a SELECT statement, then this step also generates
** all the code to implement the SELECT statement and invoke a subroutine
** to process each row of the result. (Template 2.) If the SELECT
** statement uses the the table that is being inserted into, then the
** subroutine is also coded here. That subroutine stores the SELECT
** results in a temporary table. (Template 3.)
*/
if( pSelect ){
/* Data is coming from a SELECT. Generate code to implement that SELECT
*/
int rc, iInitCode;
iInitCode = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
iSelectLoop = sqlite3VdbeCurrentAddr(v);
iInsertBlock = sqlite3VdbeMakeLabel(v);
/* Resolve the expressions in the SELECT statement and execute it. */
rc = sqlite3Select(pParse, pSelect, SRT_Subroutine, iInsertBlock,0,0,0,0);
if( rc || pParse->nErr || sqlite3_malloc_failed ) goto insert_cleanup;
iCleanup = sqlite3VdbeMakeLabel(v);
sqlite3VdbeAddOp(v, OP_Goto, 0, iCleanup);
assert( pSelect->pEList );
nColumn = pSelect->pEList->nExpr;
/* Set useTempTable to TRUE if the result of the SELECT statement
** should be written into a temporary table. Set to FALSE if each
** row of the SELECT can be written directly into the result table.
**
** A temp table must be used if the table being updated is also one
** of the tables being read by the SELECT statement. Also use a
** temp table in the case of row triggers.
*/
if( triggers_exist || selectReadsTable(pSelect, pTab->iDb, pTab->tnum) ){
useTempTable = 1;
}
if( useTempTable ){
/* Generate the subroutine that SELECT calls to process each row of
** the result. Store the result in a temporary table
*/
srcTab = pParse->nTab++;
sqlite3VdbeResolveLabel(v, iInsertBlock);
sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, 0);
sqlite3TableAffinityStr(v, pTab);
sqlite3VdbeAddOp(v, OP_NewRecno, srcTab, 0);
sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
sqlite3VdbeAddOp(v, OP_PutIntKey, srcTab, 0);
sqlite3VdbeAddOp(v, OP_Return, 0, 0);
/* The following code runs first because the GOTO at the very top
** of the program jumps to it. Create the temporary table, then jump
** back up and execute the SELECT code above.
*/
sqlite3VdbeChangeP2(v, iInitCode, sqlite3VdbeCurrentAddr(v));
sqlite3VdbeAddOp(v, OP_OpenTemp, srcTab, 0);
sqlite3VdbeAddOp(v, OP_SetNumColumns, srcTab, nColumn);
sqlite3VdbeAddOp(v, OP_Goto, 0, iSelectLoop);
sqlite3VdbeResolveLabel(v, iCleanup);
}else{
sqlite3VdbeChangeP2(v, iInitCode, sqlite3VdbeCurrentAddr(v));
}
}else{
/* This is the case if the data for the INSERT is coming from a VALUES
** clause
*/
NameContext sNC;
memset(&sNC, 0, sizeof(sNC));
sNC.pParse = pParse;
assert( pList!=0 );
srcTab = -1;
useTempTable = 0;
assert( pList );
nColumn = pList->nExpr;
for(i=0; i<nColumn; i++){
if( sqlite3ExprResolveNames(&sNC, pList->a[i].pExpr) ){
goto insert_cleanup;
}
}
}
/* Make sure the number of columns in the source data matches the number
** of columns to be inserted into the table.
*/
if( pColumn==0 && nColumn!=pTab->nCol ){
sqlite3ErrorMsg(pParse,
"table %S has %d columns but %d values were supplied",
pTabList, 0, pTab->nCol, nColumn);
goto insert_cleanup;
}
if( pColumn!=0 && nColumn!=pColumn->nId ){
sqlite3ErrorMsg(pParse, "%d values for %d columns", nColumn, pColumn->nId);
goto insert_cleanup;
}
/* If the INSERT statement included an IDLIST term, then make sure
** all elements of the IDLIST really are columns of the table and
** remember the column indices.
**
** If the table has an INTEGER PRIMARY KEY column and that column
** is named in the IDLIST, then record in the keyColumn variable
** the index into IDLIST of the primary key column. keyColumn is
** the index of the primary key as it appears in IDLIST, not as
** is appears in the original table. (The index of the primary
** key in the original table is pTab->iPKey.)
*/
if( pColumn ){
for(i=0; i<pColumn->nId; i++){
pColumn->a[i].idx = -1;
}
for(i=0; i<pColumn->nId; i++){
for(j=0; j<pTab->nCol; j++){
if( sqlite3StrICmp(pColumn->a[i].zName, pTab->aCol[j].zName)==0 ){
pColumn->a[i].idx = j;
if( j==pTab->iPKey ){
keyColumn = i;
}
break;
}
}
if( j>=pTab->nCol ){
if( sqlite3IsRowid(pColumn->a[i].zName) ){
keyColumn = i;
}else{
sqlite3ErrorMsg(pParse, "table %S has no column named %s",
pTabList, 0, pColumn->a[i].zName);
pParse->nErr++;
goto insert_cleanup;
}
}
}
}
/* If there is no IDLIST term but the table has an integer primary
** key, the set the keyColumn variable to the primary key column index
** in the original table definition.
*/
if( pColumn==0 ){
keyColumn = pTab->iPKey;
}
/* Open the temp table for FOR EACH ROW triggers
*/
if( triggers_exist ){
sqlite3VdbeAddOp(v, OP_OpenPseudo, newIdx, 0);
sqlite3VdbeAddOp(v, OP_SetNumColumns, newIdx, pTab->nCol);
}
/* Initialize the count of rows to be inserted
*/
if( db->flags & SQLITE_CountRows ){
iCntMem = pParse->nMem++;
sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
sqlite3VdbeAddOp(v, OP_MemStore, iCntMem, 1);
}
/* Open tables and indices if there are no row triggers */
if( !triggers_exist ){
base = pParse->nTab;
sqlite3OpenTableAndIndices(pParse, pTab, base, OP_OpenWrite);
}
/* If the data source is a temporary table, then we have to create
** a loop because there might be multiple rows of data. If the data
** source is a subroutine call from the SELECT statement, then we need
** to launch the SELECT statement processing.
*/
if( useTempTable ){
iBreak = sqlite3VdbeMakeLabel(v);
sqlite3VdbeAddOp(v, OP_Rewind, srcTab, iBreak);
iCont = sqlite3VdbeCurrentAddr(v);
}else if( pSelect ){
sqlite3VdbeAddOp(v, OP_Goto, 0, iSelectLoop);
sqlite3VdbeResolveLabel(v, iInsertBlock);
}
/* Run the BEFORE and INSTEAD OF triggers, if there are any
*/
endOfLoop = sqlite3VdbeMakeLabel(v);
if( triggers_exist & TRIGGER_BEFORE ){
/* build the NEW.* reference row. Note that if there is an INTEGER
** PRIMARY KEY into which a NULL is being inserted, that NULL will be
** translated into a unique ID for the row. But on a BEFORE trigger,
** we do not know what the unique ID will be (because the insert has
** not happened yet) so we substitute a rowid of -1
*/
if( keyColumn<0 ){
sqlite3VdbeAddOp(v, OP_Integer, -1, 0);
}else if( useTempTable ){
sqlite3VdbeAddOp(v, OP_Column, srcTab, keyColumn);
}else{
assert( pSelect==0 ); /* Otherwise useTempTable is true */
sqlite3ExprCode(pParse, pList->a[keyColumn].pExpr);
sqlite3VdbeAddOp(v, OP_NotNull, -1, sqlite3VdbeCurrentAddr(v)+3);
sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
sqlite3VdbeAddOp(v, OP_Integer, -1, 0);
sqlite3VdbeAddOp(v, OP_MustBeInt, 0, 0);
}
/* Create the new column data
*/
for(i=0; i<pTab->nCol; i++){
if( pColumn==0 ){
j = i;
}else{
for(j=0; j<pColumn->nId; j++){
if( pColumn->a[j].idx==i ) break;
}
}
if( pColumn && j>=pColumn->nId ){
sqlite3ExprCode(pParse, pTab->aCol[i].pDflt);
}else if( useTempTable ){
sqlite3VdbeAddOp(v, OP_Column, srcTab, j);
}else{
assert( pSelect==0 ); /* Otherwise useTempTable is true */
sqlite3ExprCodeAndCache(pParse, pList->a[j].pExpr);
}
}
sqlite3VdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
/* If this is an INSERT on a view with an INSTEAD OF INSERT trigger,
** do not attempt any conversions before assembling the record.
** If this is a real table, attempt conversions as required by the
** table column affinities.
*/
if( !isView ){
sqlite3TableAffinityStr(v, pTab);
}
sqlite3VdbeAddOp(v, OP_PutIntKey, newIdx, 0);
/* Fire BEFORE or INSTEAD OF triggers */
if( sqlite3CodeRowTrigger(pParse, TK_INSERT, 0, TRIGGER_BEFORE, pTab,
newIdx, -1, onError, endOfLoop) ){
goto insert_cleanup;
}
}
/* If any triggers exists, the opening of tables and indices is deferred
** until now.
*/
if( triggers_exist && !isView ){
base = pParse->nTab;
sqlite3OpenTableAndIndices(pParse, pTab, base, OP_OpenWrite);
}
/* Push the record number for the new entry onto the stack. The
** record number is a randomly generate integer created by NewRecno
** except when the table has an INTEGER PRIMARY KEY column, in which
** case the record number is the same as that column.
*/
if( !isView ){
if( keyColumn>=0 ){
if( useTempTable ){
sqlite3VdbeAddOp(v, OP_Column, srcTab, keyColumn);
}else if( pSelect ){
sqlite3VdbeAddOp(v, OP_Dup, nColumn - keyColumn - 1, 1);
}else{
sqlite3ExprCode(pParse, pList->a[keyColumn].pExpr);
}
/* If the PRIMARY KEY expression is NULL, then use OP_NewRecno
** to generate a unique primary key value.
*/
sqlite3VdbeAddOp(v, OP_NotNull, -1, sqlite3VdbeCurrentAddr(v)+3);
sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
sqlite3VdbeAddOp(v, OP_NewRecno, base, counterMem);
sqlite3VdbeAddOp(v, OP_MustBeInt, 0, 0);
}else{
sqlite3VdbeAddOp(v, OP_NewRecno, base, counterMem);
}
#ifndef SQLITE_OMIT_AUTOINCREMENT
if( pTab->autoInc ){
sqlite3VdbeAddOp(v, OP_MemMax, counterMem, 0);
}
#endif /* SQLITE_OMIT_AUTOINCREMENT */
/* Push onto the stack, data for all columns of the new entry, beginning
** with the first column.
*/
for(i=0; i<pTab->nCol; i++){
if( i==pTab->iPKey ){
/* The value of the INTEGER PRIMARY KEY column is always a NULL.
** Whenever this column is read, the record number will be substituted
** in its place. So will fill this column with a NULL to avoid
** taking up data space with information that will never be used. */
sqlite3VdbeAddOp(v, OP_String8, 0, 0);
continue;
}
if( pColumn==0 ){
j = i;
}else{
for(j=0; j<pColumn->nId; j++){
if( pColumn->a[j].idx==i ) break;
}
}
if( pColumn && j>=pColumn->nId ){
sqlite3ExprCode(pParse, pTab->aCol[i].pDflt);
}else if( useTempTable ){
sqlite3VdbeAddOp(v, OP_Column, srcTab, j);
}else if( pSelect ){
sqlite3VdbeAddOp(v, OP_Dup, i+nColumn-j, 1);
}else{
sqlite3ExprCode(pParse, pList->a[j].pExpr);
}
}
/* Generate code to check constraints and generate index keys and
** do the insertion.
*/
sqlite3GenerateConstraintChecks(pParse, pTab, base, 0, keyColumn>=0,
0, onError, endOfLoop);
sqlite3CompleteInsertion(pParse, pTab, base, 0,0,0,
(triggers_exist & TRIGGER_AFTER)!=0 ? newIdx : -1);
}
/* Update the count of rows that are inserted
*/
if( (db->flags & SQLITE_CountRows)!=0 ){
sqlite3VdbeAddOp(v, OP_MemIncr, iCntMem, 0);
}
if( triggers_exist ){
/* Close all tables opened */
if( !isView ){
sqlite3VdbeAddOp(v, OP_Close, base, 0);
for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
sqlite3VdbeAddOp(v, OP_Close, idx+base, 0);
}
}
/* Code AFTER triggers */
if( sqlite3CodeRowTrigger(pParse, TK_INSERT, 0, TRIGGER_AFTER, pTab,
newIdx, -1, onError, endOfLoop) ){
goto insert_cleanup;
}
}
/* The bottom of the loop, if the data source is a SELECT statement
*/
sqlite3VdbeResolveLabel(v, endOfLoop);
if( useTempTable ){
sqlite3VdbeAddOp(v, OP_Next, srcTab, iCont);
sqlite3VdbeResolveLabel(v, iBreak);
sqlite3VdbeAddOp(v, OP_Close, srcTab, 0);
}else if( pSelect ){
sqlite3VdbeAddOp(v, OP_Pop, nColumn, 0);
sqlite3VdbeAddOp(v, OP_Return, 0, 0);
sqlite3VdbeResolveLabel(v, iCleanup);
}
if( !triggers_exist ){
/* Close all tables opened */
sqlite3VdbeAddOp(v, OP_Close, base, 0);
for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
sqlite3VdbeAddOp(v, OP_Close, idx+base, 0);
}
}
#ifndef SQLITE_OMIT_AUTOINCREMENT
/* Update the sqlite_sequence table by storing the content of the
** counter value in memory counterMem back into the sqlite_sequence
** table.
*/
if( pTab->autoInc ){
int iCur = pParse->nTab;
int base = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeAddOp(v, OP_Integer, pTab->iDb, 0);
sqlite3VdbeAddOp(v, OP_OpenWrite, iCur, pDb->pSeqTab->tnum);
sqlite3VdbeAddOp(v, OP_SetNumColumns, iCur, 2);
sqlite3VdbeAddOp(v, OP_MemLoad, counterRowid, 0);
sqlite3VdbeAddOp(v, OP_NotNull, -1, base+7);
sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
sqlite3VdbeAddOp(v, OP_NewRecno, iCur, 0);
sqlite3VdbeOp3(v, OP_String8, 0, 0, pTab->zName, 0);
sqlite3VdbeAddOp(v, OP_MemLoad, counterMem, 0);
sqlite3VdbeAddOp(v, OP_MakeRecord, 2, 0);
sqlite3VdbeAddOp(v, OP_PutIntKey, iCur, 0);
sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
}
#endif
/*
** Return the number of rows inserted. If this routine is
** generating code because of a call to sqlite3NestedParse(), do not
** invoke the callback function.
*/
if( db->flags & SQLITE_CountRows && pParse->nested==0 && !pParse->trigStack ){
sqlite3VdbeAddOp(v, OP_MemLoad, iCntMem, 0);
sqlite3VdbeAddOp(v, OP_Callback, 1, 0);
sqlite3VdbeSetNumCols(v, 1);
sqlite3VdbeSetColName(v, 0, "rows inserted", P3_STATIC);
}
insert_cleanup:
sqlite3SrcListDelete(pTabList);
sqlite3ExprListDelete(pList);
sqlite3SelectDelete(pSelect);
sqlite3IdListDelete(pColumn);
}
/*
** This function is called by the parser after the table-name in
** an "ALTER TABLE <table-name> ADD" statement is parsed. Argument
** pSrc is the full-name of the table being altered.
**
** This routine makes a (partial) copy of the Table structure
** for the table being altered and sets Parse.pNewTable to point
** to it. Routines called by the parser as the column definition
** is parsed (i.e. sqlite3AddColumn()) add the new Column data to
** the copy. The copy of the Table structure is deleted by tokenize.c
** after parsing is finished.
**
** Routine sqlite3AlterFinishAddColumn() will be called to complete
** coding the "ALTER TABLE ... ADD" statement.
在“ALTER TABLE <table-name> ADD”语句里表名被解析后，这个函数调用解析器。
参数pSrc是被修改表的全名。
这个例程为表被修改制作了一个（部分）表结构的副本和设置了解析。pNewTable指向它。
例程调用解析器如同列定义被解析(即sqlite3AddColumn())添加新的列数据的副本。
解析完成后表结构的副本被 tokenize.c删除。
例程sqlite3AlterFinishAddColumn()将被实现"ALTER TABLE ... ADD" 语句代码调用
*/
void sqlite3AlterBeginAddColumn(Parse *pParse, SrcList *pSrc){
Table *pNew;
Table *pTab;
Vdbe *v;
int iDb;
int i;
int nAlloc;
sqlite3 *db = pParse->db;
/* Look up the table being altered. 查看被修改的表*/
assert( pParse->pNewTable==0 );
assert( sqlite3BtreeHoldsAllMutexes(db) );
if( db->mallocFailed ) goto exit_begin_add_column;
pTab = sqlite3LocateTable(pParse, 0, pSrc->a[0].zName, pSrc->a[0].zDatabase);
if( !pTab ) goto exit_begin_add_column;
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( IsVirtual(pTab) ){
sqlite3ErrorMsg(pParse, "virtual tables may not be altered");
goto exit_begin_add_column;
}
#endif
/* Make sure this is not an attempt to ALTER a view. 确保这不是一个ALTER查看的尝试*/
if( pTab->pSelect ){
sqlite3ErrorMsg(pParse, "Cannot add a column to a view");
goto exit_begin_add_column;
}
if( SQLITE_OK!=isSystemTable(pParse, pTab->zName) ){
goto exit_begin_add_column;
}
assert( pTab->addColOffset>0 );
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
/* Put a copy of the Table struct in Parse.pNewTable for the
** sqlite3AddColumn() function and friends to modify. But modify
** the name by adding an "sqlite_altertab_" prefix. By adding this
** prefix, we insure that the name will not collide with an existing
** table because user table are not allowed to have the "sqlite_"
** prefix on their name.
在解析器里放一个表结构的副本。pNewTable为sqlite3AddColumn() 函数和友元函数修改。
但是通过增加一个"sqlite_altertab_"前缀才能修改这个名称。
通过增加这些前缀，我们确保这个名称与存在的表不发生冲突。
因为用户表不允许在他们名称里有这 个"sqlite_"前缀。
*/
pNew = (Table*)sqlite3DbMallocZero(db, sizeof(Table));
if( !pNew ) goto exit_begin_add_column;
pParse->pNewTable = pNew;
pNew->nRef = 1;
pNew->nCol = pTab->nCol;
assert( pNew->nCol>0 );
nAlloc = (((pNew->nCol-1)/8)*8)+8;
assert( nAlloc>=pNew->nCol && nAlloc%8==0 && nAlloc-pNew->nCol<8 );
pNew->aCol = (Column*)sqlite3DbMallocZero(db, sizeof(Column)*nAlloc);
pNew->zName = sqlite3MPrintf(db, "sqlite_altertab_%s", pTab->zName);
if( !pNew->aCol || !pNew->zName ){
db->mallocFailed = 1;
goto exit_begin_add_column;
}
memcpy(pNew->aCol, pTab->aCol, sizeof(Column)*pNew->nCol);
for(i=0; i<pNew->nCol; i++){
Column *pCol = &pNew->aCol[i];
pCol->zName = sqlite3DbStrDup(db, pCol->zName);
pCol->zColl = 0;
pCol->zType = 0;
pCol->pDflt = 0;
pCol->zDflt = 0;
}
pNew->pSchema = db->aDb[iDb].pSchema;
pNew->addColOffset = pTab->addColOffset;
pNew->nRef = 1;
/* Begin a transaction and increment the schema cookie. 开始一个事务和增量cookie模式。*/
sqlite3BeginWriteOperation(pParse, 0, iDb);
v = sqlite3GetVdbe(pParse);
if( !v ) goto exit_begin_add_column;
sqlite3ChangeCookie(pParse, iDb);
exit_begin_add_column:
sqlite3SrcListDelete(db, pSrc);
return;
}
/*
** The pExpr should be a TK_COLUMN expression. The table referred to
** is in pTabList or else it is the NEW or OLD table of a trigger.
** Check to see if it is OK to read this particular column.
**
** If the auth function returns SQLITE_IGNORE, change the TK_COLUMN
** instruction into a TK_NULL. If the auth function returns SQLITE_DENY,
** then generate an error.
*/
void sqlite3AuthRead(
Parse *pParse, /* The parser context */
Expr *pExpr, /* The expression to check authorization on */
Schema *pSchema, /* The schema of the expression */
SrcList *pTabList /* All table that pExpr might refer to */
){
sqlite3 *db = pParse->db;
int rc;
Table *pTab = 0; /* The table being read */
const char *zCol; /* Name of the column of the table */
int iSrc; /* Index in pTabList->a[] of table being read */
const char *zDBase; /* Name of database being accessed */
int iDb; /* The index of the database the expression refers to */
int iCol; /* Index of column in table */
if( db->xAuth==0 ) return;
iDb = sqlite3SchemaToIndex(pParse->db, pSchema);
if( iDb<0 ){
/* An attempt to read a column out of a subquery or other
** temporary table. */
return;
}
assert( pExpr->op==TK_COLUMN || pExpr->op==TK_TRIGGER );
if( pExpr->op==TK_TRIGGER ){
pTab = pParse->pTriggerTab;
}else{
assert( pTabList );
for(iSrc=0; ALWAYS(iSrc<pTabList->nSrc); iSrc++){
if( pExpr->iTable==pTabList->a[iSrc].iCursor ){
pTab = pTabList->a[iSrc].pTab;
break;
}
}
}
iCol = pExpr->iColumn;
if( NEVER(pTab==0) ) return;
if( iCol>=0 ){
assert( iCol<pTab->nCol );
zCol = pTab->aCol[iCol].zName;
}else if( pTab->iPKey>=0 ){
assert( pTab->iPKey<pTab->nCol );
zCol = pTab->aCol[pTab->iPKey].zName;
}else{
zCol = "ROWID";
}
assert( iDb>=0 && iDb<db->nDb );
zDBase = db->aDb[iDb].zName;
rc = db->xAuth(db->pAuthArg, SQLITE_READ, pTab->zName, zCol, zDBase,
pParse->zAuthContext);
if( rc==SQLITE_IGNORE ){
pExpr->op = TK_NULL;
}else if( rc==SQLITE_DENY ){
if( db->nDb>2 || iDb!=0 ){
sqlite3ErrorMsg(pParse, "access to %s.%s.%s is prohibited",
zDBase, pTab->zName, zCol);
}else{
sqlite3ErrorMsg(pParse, "access to %s.%s is prohibited",pTab->zName,zCol);
}
pParse->rc = SQLITE_AUTH;
}else if( rc!=SQLITE_OK ){
sqliteAuthBadReturnCode(pParse);
}
}
/*
** Run the parser on the given SQL string. The parser structure is
** passed in. An SQLITE_ status code is returned. If an error occurs
** then an and attempt is made to write an error message into
** memory obtained from sqlite3_malloc() and to make *pzErrMsg point to that
** error message.
*/
int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzErrMsg){
int nErr = 0; /* Number of errors encountered */
int i; /* Loop counter */
void *pEngine; /* The LEMON-generated LALR(1) parser */
int tokenType; /* type of the next token */
int lastTokenParsed = -1; /* type of the previous token */
u8 enableLookaside; /* Saved value of db->lookaside.bEnabled */
sqlite3 *db = pParse->db; /* The database connection */
int mxSqlLen; /* Max length of an SQL string */
mxSqlLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
if( db->activeVdbeCnt==0 ){
db->u1.isInterrupted = 0;
}
pParse->rc = SQLITE_OK;
pParse->zTail = zSql;
i = 0;
assert( pzErrMsg!=0 );
pEngine = sqlite3ParserAlloc((void*(*)(size_t))sqlite3Malloc);
if( pEngine==0 ){
db->mallocFailed = 1;
return SQLITE_NOMEM;
}
assert( pParse->pNewTable==0 );
assert( pParse->pNewTrigger==0 );
assert( pParse->nVar==0 );
assert( pParse->nVarExpr==0 );
assert( pParse->nVarExprAlloc==0 );
assert( pParse->apVarExpr==0 );
enableLookaside = db->lookaside.bEnabled;
if( db->lookaside.pStart ) db->lookaside.bEnabled = 1;
while( !db->mallocFailed && zSql[i]!=0 ){
assert( i>=0 );
pParse->sLastToken.z = &zSql[i];
pParse->sLastToken.n = sqlite3GetToken((unsigned char*)&zSql[i],&tokenType);
i += pParse->sLastToken.n;
if( i>mxSqlLen ){
pParse->rc = SQLITE_TOOBIG;
break;
}
switch( tokenType ){
case TK_SPACE: {
if( db->u1.isInterrupted ){
sqlite3ErrorMsg(pParse, "interrupt");
pParse->rc = SQLITE_INTERRUPT;
goto abort_parse;
}
break;
}
case TK_ILLEGAL: {
sqlite3DbFree(db, *pzErrMsg);
*pzErrMsg = sqlite3MPrintf(db, "unrecognized token: \"%T\"",
&pParse->sLastToken);
nErr++;
goto abort_parse;
}
case TK_SEMI: {
pParse->zTail = &zSql[i];
/* Fall thru into the default case */
}
default: {
sqlite3Parser(pEngine, tokenType, pParse->sLastToken, pParse);
lastTokenParsed = tokenType;
if( pParse->rc!=SQLITE_OK ){
goto abort_parse;
}
break;
}
}
}
abort_parse:
if( zSql[i]==0 && nErr==0 && pParse->rc==SQLITE_OK ){
if( lastTokenParsed!=TK_SEMI ){
sqlite3Parser(pEngine, TK_SEMI, pParse->sLastToken, pParse);
pParse->zTail = &zSql[i];
}
sqlite3Parser(pEngine, 0, pParse->sLastToken, pParse);
}
#ifdef YYTRACKMAXSTACKDEPTH
sqlite3StatusSet(SQLITE_STATUS_PARSER_STACK,
sqlite3ParserStackPeak(pEngine)
);
#endif /* YYDEBUG */
sqlite3ParserFree(pEngine, sqlite3_free);
db->lookaside.bEnabled = enableLookaside;
if( db->mallocFailed ){
pParse->rc = SQLITE_NOMEM;
}
if( pParse->rc!=SQLITE_OK && pParse->rc!=SQLITE_DONE && pParse->zErrMsg==0 ){
sqlite3SetString(&pParse->zErrMsg, db, "%s", sqlite3ErrStr(pParse->rc));
}
assert( pzErrMsg!=0 );
if( pParse->zErrMsg ){
*pzErrMsg = pParse->zErrMsg;
pParse->zErrMsg = 0;
nErr++;
}
if( pParse->pVdbe && pParse->nErr>0 && pParse->nested==0 ){
sqlite3VdbeDelete(pParse->pVdbe);
pParse->pVdbe = 0;
}
#ifndef SQLITE_OMIT_SHARED_CACHE
if( pParse->nested==0 ){
sqlite3DbFree(db, pParse->aTableLock);
pParse->aTableLock = 0;
pParse->nTableLock = 0;
}
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
sqlite3DbFree(db, pParse->apVtabLock);
#endif
if( !IN_DECLARE_VTAB ){
/* If the pParse->declareVtab flag is set, do not delete any table
** structure built up in pParse->pNewTable. The calling code (see vtab.c)
** will take responsibility for freeing the Table structure.
*/
sqlite3DeleteTable(pParse->pNewTable);
}
sqlite3DeleteTrigger(db, pParse->pNewTrigger);
sqlite3DbFree(db, pParse->apVarExpr);
sqlite3DbFree(db, pParse->aAlias);
while( pParse->pAinc ){
AutoincInfo *p = pParse->pAinc;
pParse->pAinc = p->pNext;
sqlite3DbFree(db, p);
}
while( pParse->pZombieTab ){
Table *p = pParse->pZombieTab;
pParse->pZombieTab = p->pNextZombie;
sqlite3DeleteTable(p);
}
if( nErr>0 && pParse->rc==SQLITE_OK ){
pParse->rc = SQLITE_ERROR;
}
return nErr;
}
/*
** Process an UPDATE statement.
**
** UPDATE OR IGNORE table_wxyz SET a=b, c=d WHERE e<5 AND f NOT NULL;
** \_______/ \________/ \______/ \________________/
* onError pTabList pChanges pWhere
*/
void sqlite3Update(
Parse *pParse, /* The parser context */
SrcList *pTabList, /* The table in which we should change things */
ExprList *pChanges, /* Things to be changed */
Expr *pWhere, /* The WHERE clause. May be null */
int onError /* How to handle constraint errors */
){
int i, j; /* Loop counters */
Table *pTab; /* The table to be updated */
int addrTop = 0; /* VDBE instruction address of the start of the loop */
WhereInfo *pWInfo; /* Information about the WHERE clause */
Vdbe *v; /* The virtual database engine */
Index *pIdx; /* For looping over indices */
Index *pPk; /* The PRIMARY KEY index for WITHOUT ROWID tables */
int nIdx; /* Number of indices that need updating */
int iBaseCur; /* Base cursor number */
int iDataCur; /* Cursor for the canonical data btree */
int iIdxCur; /* Cursor for the first index */
sqlite3 *db; /* The database structure */
int *aRegIdx = 0; /* One register assigned to each index to be updated */
int *aXRef = 0; /* aXRef[i] is the index in pChanges->a[] of the
** an expression for the i-th column of the table.
** aXRef[i]==-1 if the i-th column is not changed. */
u8 *aToOpen; /* 1 for tables and indices to be opened */
u8 chngPk; /* PRIMARY KEY changed in a WITHOUT ROWID table */
u8 chngRowid; /* Rowid changed in a normal table */
u8 chngKey; /* Either chngPk or chngRowid */
Expr *pRowidExpr = 0; /* Expression defining the new record number */
AuthContext sContext; /* The authorization context */
NameContext sNC; /* The name-context to resolve expressions in */
int iDb; /* Database containing the table being updated */
int okOnePass; /* True for one-pass algorithm without the FIFO */
int hasFK; /* True if foreign key processing is required */
int labelBreak; /* Jump here to break out of UPDATE loop */
int labelContinue; /* Jump here to continue next step of UPDATE loop */
#ifndef SQLITE_OMIT_TRIGGER
int isView; /* True when updating a view (INSTEAD OF trigger) */
Trigger *pTrigger; /* List of triggers on pTab, if required */
int tmask; /* Mask of TRIGGER_BEFORE|TRIGGER_AFTER */
#endif
int newmask; /* Mask of NEW.* columns accessed by BEFORE triggers */
int iEph = 0; /* Ephemeral table holding all primary key values */
int nKey = 0; /* Number of elements in regKey for WITHOUT ROWID */
int aiCurOnePass[2]; /* The write cursors opened by WHERE_ONEPASS */
/* Register Allocations */
int regRowCount = 0; /* A count of rows changed */
int regOldRowid; /* The old rowid */
int regNewRowid; /* The new rowid */
int regNew; /* Content of the NEW.* table in triggers */
int regOld = 0; /* Content of OLD.* table in triggers */
int regRowSet = 0; /* Rowset of rows to be updated */
int regKey = 0; /* composite PRIMARY KEY value */
memset(&sContext, 0, sizeof(sContext));
db = pParse->db;
if( pParse->nErr || db->mallocFailed ){
goto update_cleanup;
}
assert( pTabList->nSrc==1 );
/* Locate the table which we want to update.
*/
pTab = sqlite3SrcListLookup(pParse, pTabList);
if( pTab==0 ) goto update_cleanup;
iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
/* Figure out if we have any triggers and if the table being
** updated is a view.
*/
#ifndef SQLITE_OMIT_TRIGGER
pTrigger = sqlite3TriggersExist(pParse, pTab, TK_UPDATE, pChanges, &tmask);
isView = pTab->pSelect!=0;
assert( pTrigger || tmask==0 );
#else
# define pTrigger 0
# define isView 0
# define tmask 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif
if( sqlite3ViewGetColumnNames(pParse, pTab) ){
goto update_cleanup;
}
if( sqlite3IsReadOnly(pParse, pTab, tmask) ){
goto update_cleanup;
}
/* Allocate a cursors for the main database table and for all indices.
** The index cursors might not be used, but if they are used they
** need to occur right after the database cursor. So go ahead and
** allocate enough space, just in case.
*/
pTabList->a[0].iCursor = iBaseCur = iDataCur = pParse->nTab++;
iIdxCur = iDataCur+1;
pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);
for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){
if( pIdx->autoIndex==2 && pPk!=0 ){
iDataCur = pParse->nTab;
pTabList->a[0].iCursor = iDataCur;
}
pParse->nTab++;
}
/* Allocate space for aXRef[], aRegIdx[], and aToOpen[].
** Initialize aXRef[] and aToOpen[] to their default values.
*/
aXRef = sqlite3DbMallocRaw(db, sizeof(int) * (pTab->nCol+nIdx) + nIdx+2 );
if( aXRef==0 ) goto update_cleanup;
aRegIdx = aXRef+pTab->nCol;
aToOpen = (u8*)(aRegIdx+nIdx);
memset(aToOpen, 1, nIdx+1);
aToOpen[nIdx+1] = 0;
for(i=0; i<pTab->nCol; i++) aXRef[i] = -1;
/* Initialize the name-context */
memset(&sNC, 0, sizeof(sNC));
sNC.pParse = pParse;
sNC.pSrcList = pTabList;
/* Resolve the column names in all the expressions of the
** of the UPDATE statement. Also find the column index
** for each column to be updated in the pChanges array. For each
** column to be updated, make sure we have authorization to change
** that column.
*/
chngRowid = chngPk = 0;
for(i=0; i<pChanges->nExpr; i++){
if( sqlite3ResolveExprNames(&sNC, pChanges->a[i].pExpr) ){
goto update_cleanup;
}
for(j=0; j<pTab->nCol; j++){
if( sqlite3StrICmp(pTab->aCol[j].zName, pChanges->a[i].zName)==0 ){
if( j==pTab->iPKey ){
chngRowid = 1;
pRowidExpr = pChanges->a[i].pExpr;
}else if( pPk && (pTab->aCol[j].colFlags & COLFLAG_PRIMKEY)!=0 ){
chngPk = 1;
}
aXRef[j] = i;
break;
}
}
if( j>=pTab->nCol ){
if( pPk==0 && sqlite3IsRowid(pChanges->a[i].zName) ){
j = -1;
chngRowid = 1;
pRowidExpr = pChanges->a[i].pExpr;
}else{
sqlite3ErrorMsg(pParse, "no such column: %s", pChanges->a[i].zName);
pParse->checkSchema = 1;
goto update_cleanup;
}
}
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int rc;
rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName,
j<0 ? "ROWID" : pTab->aCol[j].zName,
db->aDb[iDb].zName);
if( rc==SQLITE_DENY ){
goto update_cleanup;
}else if( rc==SQLITE_IGNORE ){
aXRef[j] = -1;
}
}
#endif
}
assert( (chngRowid & chngPk)==0 );
assert( chngRowid==0 || chngRowid==1 );
assert( chngPk==0 || chngPk==1 );
chngKey = chngRowid + chngPk;
/* The SET expressions are not actually used inside the WHERE loop.
** So reset the colUsed mask
*/
pTabList->a[0].colUsed = 0;
hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngKey);
/* There is one entry in the aRegIdx[] array for each index on the table
** being updated. Fill in aRegIdx[] with a register number that will hold
** the key for accessing each index.
*/
for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
int reg;
if( chngKey || hasFK || pIdx->pPartIdxWhere || pIdx==pPk ){
reg = ++pParse->nMem;
}else{
reg = 0;
for(i=0; i<pIdx->nKeyCol; i++){
if( aXRef[pIdx->aiColumn[i]]>=0 ){
reg = ++pParse->nMem;
break;
}
}
}
if( reg==0 ) aToOpen[j+1] = 0;
aRegIdx[j] = reg;
}
/* Begin generating code. */
v = sqlite3GetVdbe(pParse);
if( v==0 ) goto update_cleanup;
if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
sqlite3BeginWriteOperation(pParse, 1, iDb);
#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Virtual tables must be handled separately */
if( IsVirtual(pTab) ){
updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef,
pWhere, onError);
pWhere = 0;
pTabList = 0;
goto update_cleanup;
}
#endif
/* Allocate required registers. */
regRowSet = ++pParse->nMem;
regOldRowid = regNewRowid = ++pParse->nMem;
if( chngPk || pTrigger || hasFK ){
regOld = pParse->nMem + 1;
pParse->nMem += pTab->nCol;
}
if( chngKey || pTrigger || hasFK ){
regNewRowid = ++pParse->nMem;
}
regNew = pParse->nMem + 1;
pParse->nMem += pTab->nCol;
/* Start the view context. */
if( isView ){
sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
}
/* If we are trying to update a view, realize that view into
** a ephemeral table.
*/
#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
if( isView ){
sqlite3MaterializeView(pParse, pTab, pWhere, iDataCur);
}
#endif
/* Resolve the column names in all the expressions in the
** WHERE clause.
*/
if( sqlite3ResolveExprNames(&sNC, pWhere) ){
goto update_cleanup;
}
/* Begin the database scan
*/
if( HasRowid(pTab) ){
sqlite3VdbeAddOp3(v, OP_Null, 0, regRowSet, regOldRowid);
pWInfo = sqlite3WhereBegin(
pParse, pTabList, pWhere, 0, 0, WHERE_ONEPASS_DESIRED, iIdxCur
);
if( pWInfo==0 ) goto update_cleanup;
okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
/* Remember the rowid of every item to be updated.
*/
sqlite3VdbeAddOp2(v, OP_Rowid, iDataCur, regOldRowid);
if( !okOnePass ){
sqlite3VdbeAddOp2(v, OP_RowSetAdd, regRowSet, regOldRowid);
}
/* End the database scan loop.
*/
sqlite3WhereEnd(pWInfo);
}else{
int iPk; /* First of nPk memory cells holding PRIMARY KEY value */
i16 nPk; /* Number of components of the PRIMARY KEY */
int addrOpen; /* Address of the OpenEphemeral instruction */
assert( pPk!=0 );
nPk = pPk->nKeyCol;
iPk = pParse->nMem+1;
pParse->nMem += nPk;
regKey = ++pParse->nMem;
iEph = pParse->nTab++;
sqlite3VdbeAddOp2(v, OP_Null, 0, iPk);
addrOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEph, nPk);
sqlite3VdbeSetP4KeyInfo(pParse, pPk);
pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0,
WHERE_ONEPASS_DESIRED, iIdxCur);
if( pWInfo==0 ) goto update_cleanup;
okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
for(i=0; i<nPk; i++){
sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, pPk->aiColumn[i],
iPk+i);
}
if( okOnePass ){
sqlite3VdbeChangeToNoop(v, addrOpen);
nKey = nPk;
regKey = iPk;
}else{
sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, regKey,
sqlite3IndexAffinityStr(v, pPk), P4_TRANSIENT);
sqlite3VdbeAddOp2(v, OP_IdxInsert, iEph, regKey);
}
sqlite3WhereEnd(pWInfo);
}
/* Initialize the count of updated rows
*/
if( (db->flags & SQLITE_CountRows) && !pParse->pTriggerTab ){
regRowCount = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);
}
labelBreak = sqlite3VdbeMakeLabel(v);
if( !isView ){
/*
** Open every index that needs updating. Note that if any
** index could potentially invoke a REPLACE conflict resolution
** action, then we need to open all indices because we might need
** to be deleting some records.
*/
if( onError==OE_Replace ){
memset(aToOpen, 1, nIdx+1);
}else{
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
if( pIdx->onError==OE_Replace ){
memset(aToOpen, 1, nIdx+1);
break;
}
}
}
if( okOnePass ){
if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iBaseCur] = 0;
if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iBaseCur] = 0;
}
sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, iBaseCur, aToOpen,
0, 0);
}
/* Top of the update loop */
if( okOnePass ){
if( aToOpen[iDataCur-iBaseCur] ){
assert( pPk!=0 );
sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelBreak, regKey, nKey);
}
labelContinue = labelBreak;
sqlite3VdbeAddOp2(v, OP_IsNull, pPk ? regKey : regOldRowid, labelBreak);
}else if( pPk ){
labelContinue = sqlite3VdbeMakeLabel(v);
sqlite3VdbeAddOp2(v, OP_Rewind, iEph, labelBreak);
addrTop = sqlite3VdbeAddOp2(v, OP_RowKey, iEph, regKey);
sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue, regKey, 0);
}else{
labelContinue = sqlite3VdbeAddOp3(v, OP_RowSetRead, regRowSet, labelBreak,
regOldRowid);
sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid);
}
/* If the record number will change, set register regNewRowid to
** contain the new value. If the record number is not being modified,
** then regNewRowid is the same register as regOldRowid, which is
** already populated. */
assert( chngKey || pTrigger || hasFK || regOldRowid==regNewRowid );
if( chngRowid ){
sqlite3ExprCode(pParse, pRowidExpr, regNewRowid);
sqlite3VdbeAddOp1(v, OP_MustBeInt, regNewRowid);
}
/* Compute the old pre-UPDATE content of the row being changed, if that
** information is needed */
if( chngPk || hasFK || pTrigger ){
u32 oldmask = (hasFK ? sqlite3FkOldmask(pParse, pTab) : 0);
oldmask |= sqlite3TriggerColmask(pParse,
pTrigger, pChanges, 0, TRIGGER_BEFORE|TRIGGER_AFTER, pTab, onError
);
for(i=0; i<pTab->nCol; i++){
if( oldmask==0xffffffff
|| (i<32 && (oldmask & MASKBIT32(i))!=0)
|| (pTab->aCol[i].colFlags & COLFLAG_PRIMKEY)!=0
){
testcase( oldmask!=0xffffffff && i==31 );
sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regOld+i);
}else{
sqlite3VdbeAddOp2(v, OP_Null, 0, regOld+i);
}
}
if( chngRowid==0 && pPk==0 ){
sqlite3VdbeAddOp2(v, OP_Copy, regOldRowid, regNewRowid);
}
}
/* Populate the array of registers beginning at regNew with the new
** row data. This array is used to check constaints, create the new
** table and index records, and as the values for any new.* references
** made by triggers.
**
** If there are one or more BEFORE triggers, then do not populate the
** registers associated with columns that are (a) not modified by
** this UPDATE statement and (b) not accessed by new.* references. The
** values for registers not modified by the UPDATE must be reloaded from
** the database after the BEFORE triggers are fired anyway (as the trigger
** may have modified them). So not loading those that are not going to
** be used eliminates some redundant opcodes.
*/
newmask = sqlite3TriggerColmask(
pParse, pTrigger, pChanges, 1, TRIGGER_BEFORE, pTab, onError
);
/*sqlite3VdbeAddOp3(v, OP_Null, 0, regNew, regNew+pTab->nCol-1);*/
for(i=0; i<pTab->nCol; i++){
if( i==pTab->iPKey ){
sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i);
}else{
j = aXRef[i];
if( j>=0 ){
sqlite3ExprCode(pParse, pChanges->a[j].pExpr, regNew+i);
}else if( 0==(tmask&TRIGGER_BEFORE) || i>31 || (newmask & MASKBIT32(i)) ){
/* This branch loads the value of a column that will not be changed
** into a register. This is done if there are no BEFORE triggers, or
** if there are one or more BEFORE triggers that use this value via
** a new.* reference in a trigger program.
*/
testcase( i==31 );
testcase( i==32 );
sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regNew+i);
}else{
sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i);
}
}
}
/* Fire any BEFORE UPDATE triggers. This happens before constraints are
** verified. One could argue that this is wrong.
*/
if( tmask&TRIGGER_BEFORE ){
sqlite3VdbeAddOp2(v, OP_Affinity, regNew, pTab->nCol);
sqlite3TableAffinityStr(v, pTab);
sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges,
TRIGGER_BEFORE, pTab, regOldRowid, onError, labelContinue);
/* The row-trigger may have deleted the row being updated. In this
** case, jump to the next row. No updates or AFTER triggers are
** required. This behavior - what happens when the row being updated
** is deleted or renamed by a BEFORE trigger - is left undefined in the
** documentation.
*/
if( pPk ){
sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue,regKey,nKey);
}else{
sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid);
}
/* If it did not delete it, the row-trigger may still have modified
** some of the columns of the row being updated. Load the values for
** all columns not modified by the update statement into their
** registers in case this has happened.
*/
for(i=0; i<pTab->nCol; i++){
if( aXRef[i]<0 && i!=pTab->iPKey ){
sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regNew+i);
}
}
}
if( !isView ){
int j1 = 0; /* Address of jump instruction */
int bReplace = 0; /* True if REPLACE conflict resolution might happen */
/* Do constraint checks. */
assert( regOldRowid>0 );
sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,
regNewRowid, regOldRowid, chngKey, onError, labelContinue, &bReplace);
/* Do FK constraint checks. */
if( hasFK ){
sqlite3FkCheck(pParse, pTab, regOldRowid, 0, aXRef, chngKey);
}
/* Delete the index entries associated with the current record. */
if( bReplace || chngKey ){
if( pPk ){
j1 = sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, 0, regKey, nKey);
}else{
j1 = sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, 0, regOldRowid);
}
}
sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, aRegIdx);
/* If changing the record number, delete the old record. */
if( hasFK || chngKey || pPk!=0 ){
sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, 0);
}
if( bReplace || chngKey ){
sqlite3VdbeJumpHere(v, j1);
}
if( hasFK ){
sqlite3FkCheck(pParse, pTab, 0, regNewRowid, aXRef, chngKey);
}
/* Insert the new index entries and the new record. */
sqlite3CompleteInsertion(pParse, pTab, iDataCur, iIdxCur,
regNewRowid, aRegIdx, 1, 0, 0);
/* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to
** handle rows (possibly in other tables) that refer via a foreign key
** to the row just updated. */
if( hasFK ){
sqlite3FkActions(pParse, pTab, pChanges, regOldRowid, aXRef, chngKey);
}
}
/* Increment the row counter
*/
if( (db->flags & SQLITE_CountRows) && !pParse->pTriggerTab){
sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);
}
sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges,
TRIGGER_AFTER, pTab, regOldRowid, onError, labelContinue);
/* Repeat the above with the next record to be updated, until
** all record selected by the WHERE clause have been updated.
*/
if( okOnePass ){
/* Nothing to do at end-of-loop for a single-pass */
}else if( pPk ){
sqlite3VdbeResolveLabel(v, labelContinue);
sqlite3VdbeAddOp2(v, OP_Next, iEph, addrTop);
}else{
sqlite3VdbeAddOp2(v, OP_Goto, 0, labelContinue);
}
sqlite3VdbeResolveLabel(v, labelBreak);
/* Close all tables */
for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
assert( aRegIdx );
if( aToOpen[i+1] ){
sqlite3VdbeAddOp2(v, OP_Close, iIdxCur+i, 0);
}
}
if( iDataCur<iIdxCur ) sqlite3VdbeAddOp2(v, OP_Close, iDataCur, 0);
/* Update the sqlite_sequence table by storing the content of the
** maximum rowid counter values recorded while inserting into
** autoincrement tables.
*/
if( pParse->nested==0 && pParse->pTriggerTab==0 ){
sqlite3AutoincrementEnd(pParse);
}
/*
** Return the number of rows that were changed. If this routine is
** generating code because of a call to sqlite3NestedParse(), do not
** invoke the callback function.
*/
if( (db->flags&SQLITE_CountRows) && !pParse->pTriggerTab && !pParse->nested ){
sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1);
sqlite3VdbeSetNumCols(v, 1);
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows updated", SQLITE_STATIC);
}
update_cleanup:
sqlite3AuthContextPop(&sContext);
sqlite3DbFree(db, aXRef); /* Also frees aRegIdx[] and aToOpen[] */
sqlite3SrcListDelete(db, pTabList);
sqlite3ExprListDelete(db, pChanges);
sqlite3ExprDelete(db, pWhere);
return;
}
/*
** Generate an expression tree to implement the WHERE, ORDER BY,
** and LIMIT/OFFSET portion of DELETE and UPDATE statements.
**
** DELETE FROM table_wxyz WHERE a<5 ORDER BY a LIMIT 1;
** \__________________________/
** pLimitWhere (pInClause)
*/
Expr *sqlite3LimitWhere(
Parse *pParse, /* The parser context */
SrcList *pSrc, /* the FROM clause -- which tables to scan */
Expr *pWhere, /* The WHERE clause. May be null */
ExprList *pOrderBy, /* The ORDER BY clause. May be null */
Expr *pLimit, /* The LIMIT clause. May be null */
Expr *pOffset, /* The OFFSET clause. May be null */
char *zStmtType /* Either DELETE or UPDATE. For error messages. */
){
Expr *pWhereRowid = NULL; /* WHERE rowid .. */
Expr *pInClause = NULL; /* WHERE rowid IN ( select ) */
Expr *pSelectRowid = NULL; /* SELECT rowid ... */
ExprList *pEList = NULL; /* Expression list contaning only pSelectRowid */
SrcList *pSelectSrc = NULL; /* SELECT rowid FROM x ... (dup of pSrc) */
Select *pSelect = NULL; /* Complete SELECT tree */
/* Check that there isn't an ORDER BY without a LIMIT clause.
*/
if( pOrderBy && (pLimit == 0) ) {
sqlite3ErrorMsg(pParse, "ORDER BY without LIMIT on %s", zStmtType);
goto limit_where_cleanup_2;
}
/* We only need to generate a select expression if there
** is a limit/offset term to enforce.
*/
if( pLimit == 0 ) {
/* if pLimit is null, pOffset will always be null as well. */
assert( pOffset == 0 );
return pWhere;
}
/* Generate a select expression tree to enforce the limit/offset
** term for the DELETE or UPDATE statement. For example:
** DELETE FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
** becomes:
** DELETE FROM table_a WHERE rowid IN (
** SELECT rowid FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
** );
*/
pSelectRowid = sqlite3PExpr(pParse, TK_ROW, 0, 0, 0);
if( pSelectRowid == 0 ) goto limit_where_cleanup_2;
pEList = sqlite3ExprListAppend(pParse, 0, pSelectRowid);
if( pEList == 0 ) goto limit_where_cleanup_2;
/* duplicate the FROM clause as it is needed by both the DELETE/UPDATE tree
** and the SELECT subtree. */
pSelectSrc = sqlite3SrcListDup(pParse->db, pSrc, 0);
if( pSelectSrc == 0 ) {
sqlite3ExprListDelete(pParse->db, pEList);
goto limit_where_cleanup_2;
}
/* generate the SELECT expression tree. */
pSelect = sqlite3SelectNew(pParse,pEList,pSelectSrc,pWhere,0,0,
pOrderBy,0,pLimit,pOffset);
if( pSelect == 0 ) return 0;
/* now generate the new WHERE rowid IN clause for the DELETE/UDPATE */
pWhereRowid = sqlite3PExpr(pParse, TK_ROW, 0, 0, 0);
if( pWhereRowid == 0 ) goto limit_where_cleanup_1;
pInClause = sqlite3PExpr(pParse, TK_IN, pWhereRowid, 0, 0);
if( pInClause == 0 ) goto limit_where_cleanup_1;
pInClause->x.pSelect = pSelect;
pInClause->flags |= EP_xIsSelect;
sqlite3ExprSetHeight(pParse, pInClause);
return pInClause;
/* something went wrong. clean up anything allocated. */
limit_where_cleanup_1:
sqlite3SelectDelete(pParse->db, pSelect);
return 0;
limit_where_cleanup_2:
sqlite3ExprDelete(pParse->db, pWhere);
sqlite3ExprListDelete(pParse->db, pOrderBy);
sqlite3ExprDelete(pParse->db, pLimit);
sqlite3ExprDelete(pParse->db, pOffset);
return 0;
}