/*
** This function is called to drop a trigger from the database schema.
**
** This may be called directly from the parser and therefore identifies
** the trigger by name. The sqlite3DropTriggerPtr() routine does the
** same job as this routine except it takes a pointer to the trigger
** instead of the trigger name.
**/
void sqlite3DropTrigger(Parse *pParse, SrcList *pName) {
Trigger *pTrigger = 0;
int i;
const char *zDb;
const char *zName;
int nName;
sqlite3 *db = pParse->db;
if( sqlite3ThreadDataReadOnly()->mallocFailed ) goto drop_trigger_cleanup;
if( SQLITE_OK!=sqlite3ReadSchema(pParse) ) {
goto drop_trigger_cleanup;
}
assert( pName->nSrc==1 );
zDb = pName->a[0].zDatabase;
zName = pName->a[0].zName;
nName = strlen(zName);
for(i=OMIT_TEMPDB; i<db->nDb; i++) {
int j = (i<2) ? i^1 : i; /* Search TEMP before MAIN */
if( zDb && sqlite3StrICmp(db->aDb[j].zName, zDb) ) continue;
pTrigger = sqlite3HashFind(&(db->aDb[j].pSchema->trigHash), zName, nName+1);
if( pTrigger ) break;
}
if( !pTrigger ) {
sqlite3ErrorMsg(pParse, "no such trigger: %S", pName, 0);
goto drop_trigger_cleanup;
}
sqlite3DropTriggerPtr(pParse, pTrigger, 0);
drop_trigger_cleanup:
sqlite3SrcListDelete(pName);
}
/*
** Locate and return an entry from the db.aCollSeq hash table. If the entry
** specified by zName and nName is not found and parameter 'create' is
** true, then create a new entry. Otherwise return NULL.
**
** Each pointer stored in the sqlite3.aCollSeq hash table contains an
** array of three CollSeq structures. The first is the collation sequence
** prefferred for UTF-8, the second UTF-16le, and the third UTF-16be.
**
** Stored immediately after the three collation sequences is a copy of
** the collation sequence name. A pointer to this string is stored in
** each collation sequence structure.
*/
static CollSeq *findCollSeqEntry(
sqlite3 *db,
const char *zName,
int nName,
int create
){
CollSeq *pColl;
if( nName<0 ) nName = strlen(zName);
pColl = sqlite3HashFind(&db->aCollSeq, zName, nName);
if( 0==pColl && create ){
pColl = sqliteMalloc( 3*sizeof(*pColl) + nName + 1 );
if( pColl ){
CollSeq *pDel = 0;
pColl[0].zName = (char*)&pColl[3];
pColl[0].enc = SQLITE_UTF8;
pColl[1].zName = (char*)&pColl[3];
pColl[1].enc = SQLITE_UTF16LE;
pColl[2].zName = (char*)&pColl[3];
pColl[2].enc = SQLITE_UTF16BE;
memcpy(pColl[0].zName, zName, nName);
pColl[0].zName[nName] = 0;
pDel = sqlite3HashInsert(&db->aCollSeq, pColl[0].zName, nName, pColl);
/* If a malloc() failure occured in sqlite3HashInsert(), it will
** return the pColl pointer to be deleted (because it wasn't added
** to the hash table).
*/
assert( !pDel ||
(sqlite3ThreadDataReadOnly()->mallocFailed && pDel==pColl) );
sqliteFree(pDel);
}
}
return pColl;
}
/*
** This is the test layer's wrapper around sqlite3OsRealloc().
*/
static void * OSREALLOC(void *pRealloc, int n){
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
sqlite3_nMaxAlloc =
MAX(sqlite3_nMaxAlloc, sqlite3ThreadDataReadOnly()->nAlloc);
#endif
assert( !sqlite3_mallocDisallowed );
if( !sqlite3TestMallocFail() ){
u32 *p = (u32 *)getOsPointer(pRealloc);
checkGuards(p);
p = sqlite3OsRealloc(p, n + TESTALLOC_OVERHEAD);
applyGuards(p);
relinkAlloc(p);
return (void *)(&p[TESTALLOC_NGUARD + 2*sizeof(void *)/sizeof(u32)]);
}
return 0;
}
/*
** This is the test layer's wrapper around sqlite3OsMalloc().
*/
static void * OSMALLOC(int n){
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
sqlite3_nMaxAlloc =
MAX(sqlite3_nMaxAlloc, sqlite3ThreadDataReadOnly()->nAlloc);
#endif
assert( !sqlite3_mallocDisallowed );
if( !sqlite3TestMallocFail() ){
u32 *p;
p = (u32 *)sqlite3OsMalloc(n + TESTALLOC_OVERHEAD);
assert(p);
sqlite3_nMalloc++;
applyGuards(p);
linkAlloc(p);
return (void *)(&p[TESTALLOC_NGUARD + 2*sizeof(void *)/sizeof(u32)]);
}
return 0;
}
/*
** The parser calls this routine when it first sees a CREATE VIRTUAL TABLE
** statement. The module name has been parsed, but the optional list
** of parameters that follow the module name are still pending.
*/
void sqlite3VtabBeginParse(
Parse *pParse, /* Parsing context */
Token *pName1, /* Name of new table, or database name */
Token *pName2, /* Name of new table or NULL */
Token *pModuleName /* Name of the module for the virtual table */
){
int iDb; /* The database the table is being created in */
Table *pTable; /* The new virtual table */
#ifndef SQLITE_OMIT_SHARED_CACHE
if( sqlite3ThreadDataReadOnly()->useSharedData ){
sqlite3ErrorMsg(pParse, "Cannot use virtual tables in shared-cache mode");
return;
}
#endif
sqlite3StartTable(pParse, pName1, pName2, 0, 0, 1, 0);
pTable = pParse->pNewTable;
if( pTable==0 || pParse->nErr ) return;
assert( 0==pTable->pIndex );
iDb = sqlite3SchemaToIndex(pParse->db, pTable->pSchema);
assert( iDb>=0 );
pTable->isVirtual = 1;
pTable->nModuleArg = 0;
addModuleArgument(pTable, sqlite3NameFromToken(pModuleName));
addModuleArgument(pTable, sqlite3StrDup(pParse->db->aDb[iDb].zName));
addModuleArgument(pTable, sqlite3StrDup(pTable->zName));
pParse->sNameToken.n = pModuleName->z + pModuleName->n - pName1->z;
#ifndef SQLITE_OMIT_AUTHORIZATION
/* Creating a virtual table invokes the authorization callback twice.
** The first invocation, to obtain permission to INSERT a row into the
** sqlite_master table, has already been made by sqlite3StartTable().
** The second call, to obtain permission to create the table, is made now.
*/
if( pTable->azModuleArg ){
sqlite3AuthCheck(pParse, SQLITE_CREATE_VTABLE, pTable->zName,
pTable->azModuleArg[0], pParse->db->aDb[iDb].zName);
}
#endif
}
/*
** Execute SQL code. Return one of the SQLITE_ success/failure
** codes. Also write an error message into memory obtained from
** malloc() and make *pzErrMsg point to that message.
**
** If the SQL is a query, then for each row in the query result
** the xCallback() function is called. pArg becomes the first
** argument to xCallback(). If xCallback=NULL then no callback
** is invoked, even for queries.
*/
int sqlite3_exec(
sqlite3 *db, /* The database on which the SQL executes */
const char *zSql, /* The SQL to be executed */
sqlite3_callback xCallback, /* Invoke this callback routine */
void *pArg, /* First argument to xCallback() */
char **pzErrMsg /* Write error messages here */
){
int rc = SQLITE_OK;
const char *zLeftover;
sqlite3_stmt *pStmt = 0;
char **azCols = 0;
int nRetry = 0;
int nChange = 0;
int nCallback;
if( zSql==0 ) return SQLITE_OK;
while( (rc==SQLITE_OK || (rc==SQLITE_SCHEMA && (++nRetry)<2)) && zSql[0] ){
int nCol;
char **azVals = 0;
pStmt = 0;
rc = sqlite3_prepare(db, zSql, -1, &pStmt, &zLeftover);
if( rc!=SQLITE_OK ){
if( pStmt ) sqlite3_finalize(pStmt);
continue;
}
if( !pStmt ){
/* this happens for a comment or white-space */
zSql = zLeftover;
continue;
}
db->nChange += nChange;
nCallback = 0;
nCol = sqlite3_column_count(pStmt);
azCols = sqliteMalloc(2*nCol*sizeof(const char *));
if( nCol && !azCols ){
goto exec_out;
}
while( 1 ){
int i;
rc = sqlite3_step(pStmt);
/* Invoke the callback function if required */
if( xCallback && (SQLITE_ROW==rc ||
(SQLITE_DONE==rc && !nCallback && db->flags&SQLITE_NullCallback)) ){
if( 0==nCallback ){
for(i=0; i<nCol; i++){
azCols[i] = (char *)sqlite3_column_name(pStmt, i);
}
nCallback++;
}
if( rc==SQLITE_ROW ){
azVals = &azCols[nCol];
for(i=0; i<nCol; i++){
azVals[i] = (char *)sqlite3_column_text(pStmt, i);
}
}
if( xCallback(pArg, nCol, azVals, azCols) ){
rc = SQLITE_ABORT;
goto exec_out;
}
}
if( rc!=SQLITE_ROW ){
rc = sqlite3_finalize(pStmt);
pStmt = 0;
if( db->pVdbe==0 ){
nChange = db->nChange;
}
if( rc!=SQLITE_SCHEMA ){
nRetry = 0;
zSql = zLeftover;
while( isspace((unsigned char)zSql[0]) ) zSql++;
}
break;
}
}
sqliteFree(azCols);
azCols = 0;
}
exec_out:
if( pStmt ) sqlite3_finalize(pStmt);
if( azCols ) sqliteFree(azCols);
if( sqlite3ThreadDataReadOnly()->mallocFailed ){
rc = SQLITE_NOMEM;
sqlite3MallocClearFailed();
}
if( rc!=SQLITE_OK && rc==sqlite3_errcode(db) && pzErrMsg ){
*pzErrMsg = malloc(1+strlen(sqlite3_errmsg(db)));
if( *pzErrMsg ){
strcpy(*pzErrMsg, sqlite3_errmsg(db));
}
}else if( pzErrMsg ){
*pzErrMsg = 0;
}
return rc;
}
/*
** This procedure generates VDBE code for a single invocation of either the
** sqlite_detach() or sqlite_attach() SQL user functions.
*/
static void codeAttach(
Parse *pParse, /* The parser context */
int type, /* Either SQLITE_ATTACH or SQLITE_DETACH */
const char *zFunc, /* Either "sqlite_attach" or "sqlite_detach */
int nFunc, /* Number of args to pass to zFunc */
Expr *pAuthArg, /* Expression to pass to authorization callback */
Expr *pFilename, /* Name of database file */
Expr *pDbname, /* Name of the database to use internally */
Expr *pKey /* Database key for encryption extension */
){
int rc;
NameContext sName;
Vdbe *v;
FuncDef *pFunc;
sqlite3* db = pParse->db;
#ifndef SQLITE_OMIT_AUTHORIZATION
assert( sqlite3ThreadDataReadOnly()->mallocFailed || pAuthArg );
if( pAuthArg ){
char *zAuthArg = sqlite3NameFromToken(&pAuthArg->span);
if( !zAuthArg ){
goto attach_end;
}
rc = sqlite3AuthCheck(pParse, type, zAuthArg, 0, 0);
sqliteFree(zAuthArg);
if(rc!=SQLITE_OK ){
goto attach_end;
}
}
#endif /* SQLITE_OMIT_AUTHORIZATION */
memset(&sName, 0, sizeof(NameContext));
sName.pParse = pParse;
if(
SQLITE_OK!=(rc = resolveAttachExpr(&sName, pFilename)) ||
SQLITE_OK!=(rc = resolveAttachExpr(&sName, pDbname)) ||
SQLITE_OK!=(rc = resolveAttachExpr(&sName, pKey))
){
pParse->nErr++;
goto attach_end;
}
v = sqlite3GetVdbe(pParse);
sqlite3ExprCode(pParse, pFilename);
sqlite3ExprCode(pParse, pDbname);
sqlite3ExprCode(pParse, pKey);
assert(v || sqlite3ThreadDataReadOnly()->mallocFailed);
if( v ){
sqlite3VdbeAddOp(v, OP_Function, 0, nFunc);
pFunc = sqlite3FindFunction(db, zFunc, strlen(zFunc), nFunc, SQLITE_UTF8,0);
sqlite3VdbeChangeP3(v, -1, (char *)pFunc, P3_FUNCDEF);
/* Code an OP_Expire. For an ATTACH statement, set P1 to true (expire this
** statement only). For DETACH, set it to false (expire all existing
** statements).
*/
sqlite3VdbeAddOp(v, OP_Expire, (type==SQLITE_ATTACH), 0);
}
attach_end:
sqlite3ExprDelete(pFilename);
sqlite3ExprDelete(pDbname);
sqlite3ExprDelete(pKey);
}
/*
** 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;
int iTabDb;
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 || sqlite3ThreadDataReadOnly()->mallocFailed ) {
goto trigger_cleanup;
}
pTab = sqlite3SrcListLookup(pParse, pTableName);
if( 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( sqlite3ThreadDataReadOnly()->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. */
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].pSchema->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;
}
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*)sqliteMalloc(sizeof(Trigger));
if( pTrigger==0 ) goto trigger_cleanup;
pTrigger->name = zName;
zName = 0;
pTrigger->table = sqliteStrDup(pTableName->a[0].zName);
pTrigger->pSchema = db->aDb[iDb].pSchema;
pTrigger->pTabSchema = pTab->pSchema;
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 );
}
}
/*
** This routine is called after all of the trigger actions have been parsed
** in order to complete the process of building the trigger.
*/
void sqlite3FinishTrigger(
Parse *pParse, /* Parser context */
TriggerStep *pStepList, /* The triggered program */
Token *pAll /* Token that describes the complete CREATE TRIGGER */
) {
Trigger *pTrig = 0; /* The trigger whose construction is finishing up */
sqlite3 *db = pParse->db; /* The database */
DbFixer sFix;
int iDb; /* Database containing the trigger */
pTrig = pParse->pNewTrigger;
pParse->pNewTrigger = 0;
if( pParse->nErr || !pTrig ) goto triggerfinish_cleanup;
iDb = sqlite3SchemaToIndex(pParse->db, pTrig->pSchema);
pTrig->step_list = pStepList;
while( pStepList ) {
pStepList->pTrig = pTrig;
pStepList = pStepList->pNext;
}
if( sqlite3FixInit(&sFix, pParse, iDb, "trigger", &pTrig->nameToken)
&& sqlite3FixTriggerStep(&sFix, pTrig->step_list) ) {
goto triggerfinish_cleanup;
}
/* if we are not initializing, and this trigger is not on a TEMP table,
** build the sqlite_master entry
*/
if( !db->init.busy ) {
static const VdbeOpList insertTrig[] = {
{ OP_NewRowid, 0, 0, 0 },
{ OP_String8, 0, 0, "trigger" },
{ OP_String8, 0, 0, 0 }, /* 2: trigger name */
{ OP_String8, 0, 0, 0 }, /* 3: table name */
{ OP_Integer, 0, 0, 0 },
{ OP_String8, 0, 0, "CREATE TRIGGER "},
{ OP_String8, 0, 0, 0 }, /* 6: SQL */
{ OP_Concat, 0, 0, 0 },
{ OP_MakeRecord, 5, 0, "aaada" },
{ OP_Insert, 0, 0, 0 },
};
int addr;
Vdbe *v;
/* Make an entry in the sqlite_master table */
v = sqlite3GetVdbe(pParse);
if( v==0 ) goto triggerfinish_cleanup;
sqlite3BeginWriteOperation(pParse, 0, iDb);
sqlite3OpenMasterTable(pParse, iDb);
addr = sqlite3VdbeAddOpList(v, ArraySize(insertTrig), insertTrig);
sqlite3VdbeChangeP3(v, addr+2, pTrig->name, 0);
sqlite3VdbeChangeP3(v, addr+3, pTrig->table, 0);
sqlite3VdbeChangeP3(v, addr+6, (char*)pAll->z, pAll->n);
sqlite3ChangeCookie(db, v, iDb);
sqlite3VdbeAddOp(v, OP_Close, 0, 0);
sqlite3VdbeOp3(v, OP_ParseSchema, iDb, 0,
sqlite3MPrintf("type='trigger' AND name='%q'", pTrig->name), P3_DYNAMIC);
}
if( db->init.busy ) {
int n;
Table *pTab;
Trigger *pDel;
pDel = sqlite3HashInsert(&db->aDb[iDb].pSchema->trigHash,
pTrig->name, strlen(pTrig->name)+1, pTrig);
if( pDel ) {
assert( sqlite3ThreadDataReadOnly()->mallocFailed && pDel==pTrig );
goto triggerfinish_cleanup;
}
n = strlen(pTrig->table) + 1;
pTab = sqlite3HashFind(&pTrig->pTabSchema->tblHash, pTrig->table, n);
assert( pTab!=0 );
pTrig->pNext = pTab->pTrigger;
pTab->pTrigger = pTrig;
pTrig = 0;
}
triggerfinish_cleanup:
sqlite3DeleteTrigger(pTrig);
assert( !pParse->pNewTrigger );
sqlite3DeleteTriggerStep(pStepList);
}
