/*
** 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 sqliteAuthRead(
Parse *pParse, /* The parser context */
Expr *pExpr, /* The expression to check authorization on */
SrcList *pTabList /* All table that pExpr might refer to */
){
sqlite *db = pParse->db;
int rc;
Table *pTab; /* 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 */
if( db->xAuth==0 ) return;
assert( pExpr->op==TK_COLUMN );
for(iSrc=0; iSrc<pTabList->nSrc; iSrc++){
if( pExpr->iTable==pTabList->a[iSrc].iCursor ) break;
}
if( iSrc>=0 && iSrc<pTabList->nSrc ){
pTab = pTabList->a[iSrc].pTab;
}else{
/* This must be an attempt to read the NEW or OLD pseudo-tables
** of a trigger.
*/
TriggerStack *pStack; /* The stack of current triggers */
pStack = pParse->trigStack;
assert( pStack!=0 );
assert( pExpr->iTable==pStack->newIdx || pExpr->iTable==pStack->oldIdx );
pTab = pStack->pTab;
}
if( pTab==0 ) return;
if( pExpr->iColumn>=0 ){
assert( pExpr->iColumn<pTab->nCol );
zCol = pTab->aCol[pExpr->iColumn].zName;
}else if( pTab->iPKey>=0 ){
assert( pTab->iPKey<pTab->nCol );
zCol = pTab->aCol[pTab->iPKey].zName;
}else{
zCol = "ROWID";
}
assert( pExpr->iDb<db->nDb );
zDBase = db->aDb[pExpr->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 || pExpr->iDb!=0 ){
sqliteSetString(&pParse->zErrMsg,"access to ", zDBase, ".",
pTab->zName, ".", zCol, " is prohibited", 0);
}else{
sqliteSetString(&pParse->zErrMsg,"access to ", pTab->zName, ".",
zCol, " is prohibited", 0);
}
pParse->nErr++;
pParse->rc = SQLITE_AUTH;
}else if( rc!=SQLITE_OK ){
sqliteAuthBadReturnCode(pParse, rc);
}
}
/*
** Initialize all database files - the main database file, the file
** used to store temporary tables, and any additional database files
** created using ATTACH statements. Return a success code. If an
** error occurs, write an error message into *pzErrMsg.
**
** After the database is initialized, the SQLITE_Initialized
** bit is set in the flags field of the sqlite structure. An
** attempt is made to initialize the database as soon as it
** is opened. If that fails (perhaps because another process
** has the sqlite_master table locked) than another attempt
** is made the first time the database is accessed.
*/
int sqliteInit(sqlite *db, char **pzErrMsg){
int i, rc;
if( db->init.busy ) return SQLITE_OK;
assert( (db->flags & SQLITE_Initialized)==0 );
rc = SQLITE_OK;
db->init.busy = 1;
for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
if( DbHasProperty(db, i, DB_SchemaLoaded) ) continue;
assert( i!=1 ); /* Should have been initialized together with 0 */
rc = sqliteInitOne(db, i, pzErrMsg);
if( rc ){
sqliteResetInternalSchema(db, i);
}
}
db->init.busy = 0;
if( rc==SQLITE_OK ){
db->flags |= SQLITE_Initialized;
sqliteCommitInternalChanges(db);
}
/* If the database is in formats 1 or 2, then upgrade it to
** version 3. This will reconstruct all indices. If the
** upgrade fails for any reason (ex: out of disk space, database
** is read only, interrupt received, etc.) then fail the init.
*/
if( rc==SQLITE_OK && db->file_format<3 ){
char *zErr = 0;
InitData initData;
int meta[SQLITE_N_BTREE_META];
db->magic = SQLITE_MAGIC_OPEN;
initData.db = db;
initData.pzErrMsg = &zErr;
db->file_format = 3;
rc = sqlite_exec(db,
"BEGIN; SELECT name FROM sqlite_master WHERE type='table';",
upgrade_3_callback,
&initData,
&zErr);
if( rc==SQLITE_OK ){
sqliteBtreeGetMeta(db->aDb[0].pBt, meta);
meta[2] = 4;
sqliteBtreeUpdateMeta(db->aDb[0].pBt, meta);
sqlite_exec(db, "COMMIT", 0, 0, 0);
}
if( rc!=SQLITE_OK ){
sqliteSetString(pzErrMsg,
"unable to upgrade database to the version 2.6 format",
zErr ? ": " : 0, zErr, (char*)0);
}
sqlite_freemem(zErr);
}
if( rc!=SQLITE_OK ){
db->flags &= ~SQLITE_Initialized;
}
return rc;
}
/*
** 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){
char zBuf[20];
sprintf(zBuf, "(%d)", rc);
sqliteSetString(&pParse->zErrMsg, "illegal return value ", zBuf,
" from the authorization function - should be SQLITE_OK, "
"SQLITE_IGNORE, or SQLITE_DENY", 0);
pParse->nErr++;
pParse->rc = SQLITE_MISUSE;
}
/*
* A string-manipulation helper function for check_redblack_tree(). If (orig ==
* NULL) a copy of val is returned. If (orig != NULL) then a copy of the *
* concatenation of orig and val is returned. The original orig is deleted
* (using sqliteFree()).
*/
static char *append_val(char * orig, char const * val){
char *z;
if( !orig ){
z = sqliteStrDup( val );
} else{
z = 0;
sqliteSetString(&z, orig, val, (char*)0);
sqliteFree( orig );
}
return z;
}
/*
** Give a listing of the program in the virtual machine.
**
** The interface is the same as sqliteVdbeExec(). But instead of
** running the code, it invokes the callback once for each instruction.
** This feature is used to implement "EXPLAIN".
*/
int sqliteVdbeList(
Vdbe *p /* The VDBE */
){
sqlite *db = p->db;
int i;
int rc = SQLITE_OK;
static char *azColumnNames[] = {
"addr", "opcode", "p1", "p2", "p3",
"int", "text", "int", "int", "text",
0
};
assert( p->popStack==0 );
assert( p->explain );
p->azColName = azColumnNames;
p->azResColumn = p->zArgv;
for(i=0; i<5; i++) p->zArgv[i] = p->aStack[i].zShort;
i = p->pc;
if( i>=p->nOp ){
p->rc = SQLITE_OK;
rc = SQLITE_DONE;
}else if( db->flags & SQLITE_Interrupt ){
db->flags &= ~SQLITE_Interrupt;
if( db->magic!=SQLITE_MAGIC_BUSY ){
p->rc = SQLITE_MISUSE;
}else{
p->rc = SQLITE_INTERRUPT;
}
rc = SQLITE_ERROR;
sqliteSetString(&p->zErrMsg, sqlite_error_string(p->rc), (char*)0);
}else{
sprintf(p->zArgv[0],"%d",i);
sprintf(p->zArgv[2],"%d", p->aOp[i].p1);
sprintf(p->zArgv[3],"%d", p->aOp[i].p2);
if( p->aOp[i].p3type==P3_POINTER ){
sprintf(p->aStack[4].zShort, "ptr(%#x)", (int)p->aOp[i].p3);
p->zArgv[4] = p->aStack[4].zShort;
}else{
p->zArgv[4] = p->aOp[i].p3;
}
p->zArgv[1] = sqliteOpcodeNames[p->aOp[i].opcode];
p->pc = i+1;
p->azResColumn = p->zArgv;
p->nResColumn = 5;
p->rc = SQLITE_OK;
rc = SQLITE_ROW;
}
return rc;
}
/*
** Clean up and delete a VDBE after execution. Return an integer which is
** the result code. Write any error message text into *pzErrMsg.
*/
int sqliteVdbeFinalize(Vdbe *p, char **pzErrMsg){
int rc;
sqlite *db;
if( p->magic!=VDBE_MAGIC_RUN && p->magic!=VDBE_MAGIC_HALT ){
sqliteSetString(pzErrMsg, sqlite_error_string(SQLITE_MISUSE), (char*)0);
return SQLITE_MISUSE;
}
db = p->db;
rc = sqliteVdbeReset(p, pzErrMsg);
sqliteVdbeDelete(p);
if( db->want_to_close && db->pVdbe==0 ){
sqlite_close(db);
}
if( rc==SQLITE_SCHEMA ){
sqliteResetInternalSchema(db, 0);
}
return rc;
}
/*
** Do an authorization check using the code and arguments given. Return
** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY. If SQLITE_DENY
** is returned, then the error count and error message in pParse are
** modified appropriately.
*/
int sqliteAuthCheck(
Parse *pParse,
int code,
const char *zArg1,
const char *zArg2,
const char *zArg3
){
sqlite *db = pParse->db;
int rc;
if( db->xAuth==0 ){
return SQLITE_OK;
}
rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext);
if( rc==SQLITE_DENY ){
sqliteSetString(&pParse->zErrMsg, "not authorized", 0);
pParse->rc = SQLITE_AUTH;
pParse->nErr++;
}else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){
rc = SQLITE_DENY;
sqliteAuthBadReturnCode(pParse, rc);
}
return rc;
}
/*
** Run the parser on the given SQL string. The parser structure is
** passed in. An SQLITE_ status code is returned. If an error occurs
** and pzErrMsg!=NULL then an error message might be written into
** memory obtained from malloc() and *pzErrMsg made to point to that
** error message. Or maybe not.
*/
int sqliteRunParser(Parse *pParse, const char *zSql, char **pzErrMsg){
int nErr = 0;
int i;
void *pEngine;
int tokenType;
int lastTokenParsed = -1;
sqlite *db = pParse->db;
extern void *sqliteParserAlloc(void*(*)(int));
extern void sqliteParserFree(void*, void(*)(void*));
extern int sqliteParser(void*, int, Token, Parse*);
db->flags &= ~SQLITE_Interrupt;
pParse->rc = SQLITE_OK;
i = 0;
pEngine = sqliteParserAlloc((void*(*)(int))malloc);
if( pEngine==0 ){
sqliteSetString(pzErrMsg, "out of memory", (char*)0);
return 1;
}
pParse->sLastToken.dyn = 0;
pParse->zTail = zSql;
while( sqlite_malloc_failed==0 && zSql[i]!=0 ){
assert( i>=0 );
pParse->sLastToken.z = &zSql[i];
assert( pParse->sLastToken.dyn==0 );
pParse->sLastToken.n = sqliteGetToken((unsigned char*)&zSql[i], &tokenType);
i += pParse->sLastToken.n;
switch( tokenType ){
case TK_SPACE:
case TK_COMMENT: {
if( (db->flags & SQLITE_Interrupt)!=0 ){
pParse->rc = SQLITE_INTERRUPT;
sqliteSetString(pzErrMsg, "interrupt", (char*)0);
goto abort_parse;
}
break;
}
case TK_ILLEGAL: {
sqliteSetNString(pzErrMsg, "unrecognized token: \"", -1,
pParse->sLastToken.z, pParse->sLastToken.n, "\"", 1, 0);
nErr++;
goto abort_parse;
}
case TK_SEMI: {
pParse->zTail = &zSql[i];
/* Fall thru into the default case */
}
default: {
sqliteParser(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 ){
sqliteParser(pEngine, TK_SEMI, pParse->sLastToken, pParse);
pParse->zTail = &zSql[i];
}
sqliteParser(pEngine, 0, pParse->sLastToken, pParse);
}
sqliteParserFree(pEngine, free);
if( pParse->rc!=SQLITE_OK && pParse->rc!=SQLITE_DONE && pParse->zErrMsg==0 ){
sqliteSetString(&pParse->zErrMsg, sqlite_error_string(pParse->rc),
(char*)0);
}
if( pParse->zErrMsg ){
if( pzErrMsg && *pzErrMsg==0 ){
*pzErrMsg = pParse->zErrMsg;
}else{
sqliteFree(pParse->zErrMsg);
}
pParse->zErrMsg = 0;
if( !nErr ) nErr++;
}
if( pParse->pVdbe && pParse->nErr>0 ){
sqliteVdbeDelete(pParse->pVdbe);
pParse->pVdbe = 0;
}
if( pParse->pNewTable ){
sqliteDeleteTable(pParse->db, pParse->pNewTable);
pParse->pNewTable = 0;
}
if( pParse->pNewTrigger ){
sqliteDeleteTrigger(pParse->pNewTrigger);
pParse->pNewTrigger = 0;
}
if( nErr>0 && (pParse->rc==SQLITE_OK || pParse->rc==SQLITE_DONE) ){
pParse->rc = SQLITE_ERROR;
}
return nErr;
}
/*
** Compile a single statement of SQL into a virtual machine. 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.
*/
int sqlite_compile(
sqlite *db, /* The database on which the SQL executes */
const char *zSql, /* The SQL to be executed */
const char **pzTail, /* OUT: Next statement after the first */
sqlite_vm **ppVm, /* OUT: The virtual machine */
char **pzErrMsg /* OUT: Write error messages here */
){
Parse sParse;
if( pzErrMsg ) *pzErrMsg = 0;
if( sqliteSafetyOn(db) ) goto exec_misuse;
if( !db->init.busy ){
if( (db->flags & SQLITE_Initialized)==0 ){
int rc, cnt = 1;
while( (rc = sqliteInit(db, pzErrMsg))==SQLITE_BUSY
&& db->xBusyCallback
&& db->xBusyCallback(db->pBusyArg, "", cnt++)!=0 ){}
if( rc!=SQLITE_OK ){
sqliteStrRealloc(pzErrMsg);
sqliteSafetyOff(db);
return rc;
}
if( pzErrMsg ){
sqliteFree(*pzErrMsg);
*pzErrMsg = 0;
}
}
if( db->file_format<3 ){
sqliteSafetyOff(db);
sqliteSetString(pzErrMsg, "obsolete database file format", (char*)0);
return SQLITE_ERROR;
}
}
assert( (db->flags & SQLITE_Initialized)!=0 || db->init.busy );
if( db->pVdbe==0 ){ db->nChange = 0; }
memset(&sParse, 0, sizeof(sParse));
sParse.db = db;
sqliteRunParser(&sParse, zSql, pzErrMsg);
if( db->xTrace && !db->init.busy ){
/* Trace only the statment that was compiled.
** Make a copy of that part of the SQL string since zSQL is const
** and we must pass a zero terminated string to the trace function
** The copy is unnecessary if the tail pointer is pointing at the
** beginnig or end of the SQL string.
*/
if( sParse.zTail && sParse.zTail!=zSql && *sParse.zTail ){
char *tmpSql = sqliteStrNDup(zSql, sParse.zTail - zSql);
if( tmpSql ){
db->xTrace(db->pTraceArg, tmpSql);
free(tmpSql);
}else{
/* If a memory error occurred during the copy,
** trace entire SQL string and fall through to the
** sqlite_malloc_failed test to report the error.
*/
db->xTrace(db->pTraceArg, zSql);
}
}else{
db->xTrace(db->pTraceArg, zSql);
}
}
if( sqlite_malloc_failed ){
sqliteSetString(pzErrMsg, "out of memory", (char*)0);
sParse.rc = SQLITE_NOMEM;
sqliteRollbackAll(db);
sqliteResetInternalSchema(db, 0);
db->flags &= ~SQLITE_InTrans;
}
if( sParse.rc==SQLITE_DONE ) sParse.rc = SQLITE_OK;
if( sParse.rc!=SQLITE_OK && pzErrMsg && *pzErrMsg==0 ){
sqliteSetString(pzErrMsg, sqlite_error_string(sParse.rc), (char*)0);
}
sqliteStrRealloc(pzErrMsg);
if( sParse.rc==SQLITE_SCHEMA ){
sqliteResetInternalSchema(db, 0);
}
assert( ppVm );
*ppVm = (sqlite_vm*)sParse.pVdbe;
if( pzTail ) *pzTail = sParse.zTail;
if( sqliteSafetyOff(db) ) goto exec_misuse;
return sParse.rc;
exec_misuse:
if( pzErrMsg ){
*pzErrMsg = 0;
sqliteSetString(pzErrMsg, sqlite_error_string(SQLITE_MISUSE), (char*)0);
sqliteStrRealloc(pzErrMsg);
}
return SQLITE_MISUSE;
}
/*
** Open a new SQLite database. Construct an "sqlite" structure to define
** the state of this database and return a pointer to that structure.
**
** An attempt is made to initialize the in-memory data structures that
** hold the database schema. But if this fails (because the schema file
** is locked) then that step is deferred until the first call to
** sqlite_exec().
*/
sqlite *sqlite_open(const char *zFilename, int mode, char **pzErrMsg){
sqlite *db;
int rc, i;
/* Allocate the sqlite data structure */
db = sqliteMalloc( sizeof(sqlite) );
if( pzErrMsg ) *pzErrMsg = 0;
if( db==0 ) goto no_mem_on_open;
db->onError = OE_Default;
db->priorNewRowid = 0;
db->magic = SQLITE_MAGIC_BUSY;
db->nDb = 2;
db->aDb = db->aDbStatic;
/* db->flags |= SQLITE_ShortColNames; */
sqliteHashInit(&db->aFunc, SQLITE_HASH_STRING, 1);
for(i=0; i<db->nDb; i++){
sqliteHashInit(&db->aDb[i].tblHash, SQLITE_HASH_STRING, 0);
sqliteHashInit(&db->aDb[i].idxHash, SQLITE_HASH_STRING, 0);
sqliteHashInit(&db->aDb[i].trigHash, SQLITE_HASH_STRING, 0);
sqliteHashInit(&db->aDb[i].aFKey, SQLITE_HASH_STRING, 1);
}
/* Open the backend database driver */
if( zFilename[0]==':' && strcmp(zFilename,":memory:")==0 ){
db->temp_store = 2;
}
rc = sqliteBtreeFactory(db, zFilename, 0, MAX_PAGES, &db->aDb[0].pBt);
if( rc!=SQLITE_OK ){
switch( rc ){
default: {
sqliteSetString(pzErrMsg, "unable to open database: ",
zFilename, (char*)0);
}
}
sqliteFree(db);
sqliteStrRealloc(pzErrMsg);
return 0;
}
db->aDb[0].zName = "main";
db->aDb[1].zName = "temp";
/* Attempt to read the schema */
sqliteRegisterBuiltinFunctions(db);
rc = sqliteInit(db, pzErrMsg);
db->magic = SQLITE_MAGIC_OPEN;
if( sqlite_malloc_failed ){
sqlite_close(db);
goto no_mem_on_open;
}else if( rc!=SQLITE_OK && rc!=SQLITE_BUSY ){
sqlite_close(db);
sqliteStrRealloc(pzErrMsg);
return 0;
}else if( pzErrMsg ){
sqliteFree(*pzErrMsg);
*pzErrMsg = 0;
}
/* Return a pointer to the newly opened database structure */
return db;
no_mem_on_open:
sqliteSetString(pzErrMsg, "out of memory", (char*)0);
sqliteStrRealloc(pzErrMsg);
return 0;
}
/*
** Fill the InitData structure with an error message that indicates
** that the database is corrupt.
*/
static void corruptSchema(InitData *pData, const char *zExtra){
sqliteSetString(pData->pzErrMsg, "malformed database schema",
zExtra!=0 && zExtra[0]!=0 ? " - " : (char*)0, zExtra, (char*)0);
}
/*
** Attempt to read the database schema and initialize internal
** data structures for a single database file. The index of the
** database file is given by iDb. iDb==0 is used for the main
** database. iDb==1 should never be used. iDb>=2 is used for
** auxiliary databases. Return one of the SQLITE_ error codes to
** indicate success or failure.
*/
static int sqliteInitOne(sqlite *db, int iDb, char **pzErrMsg){
int rc;
BtCursor *curMain;
int size;
Table *pTab;
char const *azArg[6];
char zDbNum[30];
int meta[SQLITE_N_BTREE_META];
InitData initData;
char const *zMasterSchema;
char const *zMasterName;
char *zSql = 0;
/*
** The master database table has a structure like this
*/
static char master_schema[] =
"CREATE TABLE sqlite_master(\n"
" type text,\n"
" name text,\n"
" tbl_name text,\n"
" rootpage integer,\n"
" sql text\n"
")"
;
static char temp_master_schema[] =
"CREATE TEMP TABLE sqlite_temp_master(\n"
" type text,\n"
" name text,\n"
" tbl_name text,\n"
" rootpage integer,\n"
" sql text\n"
")"
;
assert( iDb>=0 && iDb<db->nDb );
/* zMasterSchema and zInitScript are set to point at the master schema
** and initialisation script appropriate for the database being
** initialised. zMasterName is the name of the master table.
*/
if( iDb==1 ){
zMasterSchema = temp_master_schema;
zMasterName = TEMP_MASTER_NAME;
}else{
zMasterSchema = master_schema;
zMasterName = MASTER_NAME;
}
/* Construct the schema table.
*/
sqliteSafetyOff(db);
azArg[0] = "table";
azArg[1] = zMasterName;
azArg[2] = "2";
azArg[3] = zMasterSchema;
sprintf(zDbNum, "%d", iDb);
azArg[4] = zDbNum;
azArg[5] = 0;
initData.db = db;
initData.pzErrMsg = pzErrMsg;
sqliteInitCallback(&initData, 5, (char **)azArg, 0);
pTab = sqliteFindTable(db, zMasterName, db->aDb[iDb].zName);
if( pTab ){
pTab->readOnly = 1;
}else{
return SQLITE_NOMEM;
}
sqliteSafetyOn(db);
/* Create a cursor to hold the database open
*/
if( db->aDb[iDb].pBt==0 ) return SQLITE_OK;
rc = sqliteBtreeCursor(db->aDb[iDb].pBt, 2, 0, &curMain);
if( rc ){
sqliteSetString(pzErrMsg, sqlite_error_string(rc), (char*)0);
return rc;
}
/* Get the database meta information
*/
rc = sqliteBtreeGetMeta(db->aDb[iDb].pBt, meta);
if( rc ){
sqliteSetString(pzErrMsg, sqlite_error_string(rc), (char*)0);
sqliteBtreeCloseCursor(curMain);
return rc;
}
db->aDb[iDb].schema_cookie = meta[1];
if( iDb==0 ){
db->next_cookie = meta[1];
db->file_format = meta[2];
size = meta[3];
if( size==0 ){ size = MAX_PAGES; }
db->cache_size = size;
db->safety_level = meta[4];
if( meta[6]>0 && meta[6]<=2 && db->temp_store==0 ){
db->temp_store = meta[6];
}
if( db->safety_level==0 ) db->safety_level = 2;
/*
** file_format==1 Version 2.1.0.
** file_format==2 Version 2.2.0. Add support for INTEGER PRIMARY KEY.
** file_format==3 Version 2.6.0. Fix empty-string index bug.
** file_format==4 Version 2.7.0. Add support for separate numeric and
** text datatypes.
*/
if( db->file_format==0 ){
/* This happens if the database was initially empty */
db->file_format = 4;
}else if( db->file_format>4 ){
sqliteBtreeCloseCursor(curMain);
sqliteSetString(pzErrMsg, "unsupported file format", (char*)0);
return SQLITE_ERROR;
}
}else if( iDb!=1 && (db->file_format!=meta[2] || db->file_format<4) ){
assert( db->file_format>=4 );
if( meta[2]==0 ){
sqliteSetString(pzErrMsg, "cannot attach empty database: ",
db->aDb[iDb].zName, (char*)0);
}else{
sqliteSetString(pzErrMsg, "incompatible file format in auxiliary "
"database: ", db->aDb[iDb].zName, (char*)0);
}
sqliteBtreeClose(db->aDb[iDb].pBt);
db->aDb[iDb].pBt = 0;
return SQLITE_FORMAT;
}
sqliteBtreeSetCacheSize(db->aDb[iDb].pBt, db->cache_size);
sqliteBtreeSetSafetyLevel(db->aDb[iDb].pBt, meta[4]==0 ? 2 : meta[4]);
/* Read the schema information out of the schema tables
*/
assert( db->init.busy );
sqliteSafetyOff(db);
/* The following SQL will read the schema from the master tables.
** The first version works with SQLite file formats 2 or greater.
** The second version is for format 1 files.
**
** Beginning with file format 2, the rowid for new table entries
** (including entries in sqlite_master) is an increasing integer.
** So for file format 2 and later, we can play back sqlite_master
** and all the CREATE statements will appear in the right order.
** But with file format 1, table entries were random and so we
** have to make sure the CREATE TABLEs occur before their corresponding
** CREATE INDEXs. (We don't have to deal with CREATE VIEW or
** CREATE TRIGGER in file format 1 because those constructs did
** not exist then.)
*/
if( db->file_format>=2 ){
sqliteSetString(&zSql,
"SELECT type, name, rootpage, sql, ", zDbNum, " FROM \"",
db->aDb[iDb].zName, "\".", zMasterName, (char*)0);
}else{
sqliteSetString(&zSql,
"SELECT type, name, rootpage, sql, ", zDbNum, " FROM \"",
db->aDb[iDb].zName, "\".", zMasterName,
" WHERE type IN ('table', 'index')"
" ORDER BY CASE type WHEN 'table' THEN 0 ELSE 1 END", (char*)0);
}
rc = sqlite_exec(db, zSql, sqliteInitCallback, &initData, 0);
sqliteFree(zSql);
sqliteSafetyOn(db);
sqliteBtreeCloseCursor(curMain);
if( sqlite_malloc_failed ){
sqliteSetString(pzErrMsg, "out of memory", (char*)0);
rc = SQLITE_NOMEM;
sqliteResetInternalSchema(db, 0);
}
if( rc==SQLITE_OK ){
DbSetProperty(db, iDb, DB_SchemaLoaded);
}else{
sqliteResetInternalSchema(db, iDb);
}
return rc;
}
/*
** Clean up a VDBE after execution but do not delete the VDBE just yet.
** Write any error messages into *pzErrMsg. Return the result code.
**
** After this routine is run, the VDBE should be ready to be executed
** again.
*/
int sqliteVdbeReset(Vdbe *p, char **pzErrMsg){
sqlite *db = p->db;
int i;
if( p->magic!=VDBE_MAGIC_RUN && p->magic!=VDBE_MAGIC_HALT ){
sqliteSetString(pzErrMsg, sqlite_error_string(SQLITE_MISUSE), (char*)0);
return SQLITE_MISUSE;
}
if( p->zErrMsg ){
if( pzErrMsg && *pzErrMsg==0 ){
*pzErrMsg = p->zErrMsg;
}else{
sqliteFree(p->zErrMsg);
}
p->zErrMsg = 0;
}else if( p->rc ){
sqliteSetString(pzErrMsg, sqlite_error_string(p->rc), (char*)0);
}
Cleanup(p);
if( p->rc!=SQLITE_OK ){
switch( p->errorAction ){
case OE_Abort: {
if( !p->undoTransOnError ){
for(i=0; i<db->nDb; i++){
if( db->aDb[i].pBt ){
sqliteBtreeRollbackCkpt(db->aDb[i].pBt);
}
}
break;
}
/* Fall through to ROLLBACK */
}
case OE_Rollback: {
sqliteRollbackAll(db);
db->flags &= ~SQLITE_InTrans;
db->onError = OE_Default;
break;
}
default: {
if( p->undoTransOnError ){
sqliteRollbackAll(db);
db->flags &= ~SQLITE_InTrans;
db->onError = OE_Default;
}
break;
}
}
sqliteRollbackInternalChanges(db);
}
for(i=0; i<db->nDb; i++){
if( db->aDb[i].pBt && db->aDb[i].inTrans==2 ){
sqliteBtreeCommitCkpt(db->aDb[i].pBt);
db->aDb[i].inTrans = 1;
}
}
assert( p->pTos<&p->aStack[p->pc] || sqlite_malloc_failed==1 );
#ifdef VDBE_PROFILE
{
FILE *out = fopen("vdbe_profile.out", "a");
if( out ){
int i;
fprintf(out, "---- ");
for(i=0; i<p->nOp; i++){
fprintf(out, "%02x", p->aOp[i].opcode);
}
fprintf(out, "\n");
for(i=0; i<p->nOp; i++){
fprintf(out, "%6d %10lld %8lld ",
p->aOp[i].cnt,
p->aOp[i].cycles,
p->aOp[i].cnt>0 ? p->aOp[i].cycles/p->aOp[i].cnt : 0
);
sqliteVdbePrintOp(out, i, &p->aOp[i]);
}
fclose(out);
}
}
#endif
p->magic = VDBE_MAGIC_INIT;
return p->rc;
}
/*
** Generate code to do a constraint check prior to an INSERT or an UPDATE.
**
** When this routine is called, the stack contains (from bottom to top)
** the following values:
**
** 1. The recno of the row to be updated before the update. This
** value is omitted unless we are doing an UPDATE that involves a
** change to the record number.
**
** 2. The recno of the row after the update.
**
** 3. The data in the first column of the entry after the update.
**
** i. Data from middle columns...
**
** N. The data in the last column of the entry after the update.
**
** The old recno shown as entry (1) above is omitted unless both isUpdate
** and recnoChng are 1. isUpdate is true for UPDATEs and false for
** INSERTs and recnoChng is true if the record number is being changed.
**
** The code generated by this routine pushes additional entries onto
** the stack which are the keys for new index entries for the new record.
** The order of index keys is the same as the order of the indices on
** the pTable->pIndex list. A key is only created for index i if
** aIdxUsed!=0 and aIdxUsed[i]!=0.
**
** This routine also generates code to check constraints. NOT NULL,
** CHECK, and UNIQUE constraints are all checked. If a constraint fails,
** then the appropriate action is performed. There are five possible
** actions: ROLLBACK, ABORT, FAIL, REPLACE, and IGNORE.
**
** Constraint type Action What Happens
** --------------- ---------- ----------------------------------------
** any ROLLBACK The current transaction is rolled back and
** sqlite_exec() returns immediately with a
** return code of SQLITE_CONSTRAINT.
**
** any ABORT Back out changes from the current command
** only (do not do a complete rollback) then
** cause sqlite_exec() to return immediately
** with SQLITE_CONSTRAINT.
**
** any FAIL Sqlite_exec() returns immediately with a
** return code of SQLITE_CONSTRAINT. The
** transaction is not rolled back and any
** prior changes are retained.
**
** any IGNORE The record number and data is popped from
** the stack and there is an immediate jump
** to label ignoreDest.
**
** NOT NULL REPLACE The NULL value is replace by the default
** value for that column. If the default value
** is NULL, the action is the same as ABORT.
**
** UNIQUE REPLACE The other row that conflicts with the row
** being inserted is removed.
**
** CHECK REPLACE Illegal. The results in an exception.
**
** Which action to take is determined by the overrideError parameter.
** Or if overrideError==OE_Default, then the pParse->onError parameter
** is used. Or if pParse->onError==OE_Default then the onError value
** for the constraint is used.
**
** The calling routine must open a read/write cursor for pTab with
** cursor number "base". All indices of pTab must also have open
** read/write cursors with cursor number base+i for the i-th cursor.
** Except, if there is no possibility of a REPLACE action then
** cursors do not need to be open for indices where aIdxUsed[i]==0.
**
** If the isUpdate flag is true, it means that the "base" cursor is
** initially pointing to an entry that is being updated. The isUpdate
** flag causes extra code to be generated so that the "base" cursor
** is still pointing at the same entry after the routine returns.
** Without the isUpdate flag, the "base" cursor might be moved.
*/
void sqliteGenerateConstraintChecks(
Parse *pParse, /* The parser context */
Table *pTab, /* the table into which we are inserting */
int base, /* Index of a read/write cursor pointing at pTab */
char *aIdxUsed, /* Which indices are used. NULL means all are used */
int recnoChng, /* True if the record number will change */
int isUpdate, /* True for UPDATE, False for INSERT */
int overrideError, /* Override onError to this if not OE_Default */
int ignoreDest /* Jump to this label on an OE_Ignore resolution */
){
int i;
Vdbe *v;
int nCol;
int onError;
int addr;
int extra;
int iCur;
Index *pIdx;
int seenReplace = 0;
int jumpInst1, jumpInst2;
int contAddr;
int hasTwoRecnos = (isUpdate && recnoChng);
v = sqliteGetVdbe(pParse);
assert( v!=0 );
assert( pTab->pSelect==0 ); /* This table is not a VIEW */
nCol = pTab->nCol;
/* Test all NOT NULL constraints.
*/
for(i=0; i<nCol; i++){
if( i==pTab->iPKey ){
continue;
}
onError = pTab->aCol[i].notNull;
if( onError==OE_None ) continue;
if( overrideError!=OE_Default ){
onError = overrideError;
}else if( pParse->db->onError!=OE_Default ){
onError = pParse->db->onError;
}else if( onError==OE_Default ){
onError = OE_Abort;
}
if( onError==OE_Replace && pTab->aCol[i].zDflt==0 ){
onError = OE_Abort;
}
sqliteVdbeAddOp(v, OP_Dup, nCol-1-i, 1);
addr = sqliteVdbeAddOp(v, OP_NotNull, 1, 0);
switch( onError ){
case OE_Rollback:
case OE_Abort:
case OE_Fail: {
char *zMsg = 0;
sqliteVdbeAddOp(v, OP_Halt, SQLITE_CONSTRAINT, onError);
sqliteSetString(&zMsg, pTab->zName, ".", pTab->aCol[i].zName,
" may not be NULL", (char*)0);
sqliteVdbeChangeP3(v, -1, zMsg, P3_DYNAMIC);
break;
}
case OE_Ignore: {
sqliteVdbeAddOp(v, OP_Pop, nCol+1+hasTwoRecnos, 0);
sqliteVdbeAddOp(v, OP_Goto, 0, ignoreDest);
break;
}
case OE_Replace: {
sqliteVdbeOp3(v, OP_String, 0, 0, pTab->aCol[i].zDflt, P3_STATIC);
sqliteVdbeAddOp(v, OP_Push, nCol-i, 0);
break;
}
default: assert(0);
}
sqliteVdbeChangeP2(v, addr, sqliteVdbeCurrentAddr(v));
}
/* Test all CHECK constraints
*/
/**** TBD ****/
/* If we have an INTEGER PRIMARY KEY, make sure the primary key
** of the new record does not previously exist. Except, if this
** is an UPDATE and the primary key is not changing, that is OK.
*/
if( recnoChng ){
onError = pTab->keyConf;
if( overrideError!=OE_Default ){
onError = overrideError;
}else if( pParse->db->onError!=OE_Default ){
onError = pParse->db->onError;
}else if( onError==OE_Default ){
onError = OE_Abort;
}
if( isUpdate ){
sqliteVdbeAddOp(v, OP_Dup, nCol+1, 1);
sqliteVdbeAddOp(v, OP_Dup, nCol+1, 1);
jumpInst1 = sqliteVdbeAddOp(v, OP_Eq, 0, 0);
}
sqliteVdbeAddOp(v, OP_Dup, nCol, 1);
jumpInst2 = sqliteVdbeAddOp(v, OP_NotExists, base, 0);
switch( onError ){
default: {
onError = OE_Abort;
/* Fall thru into the next case */
}
case OE_Rollback:
case OE_Abort:
case OE_Fail: {
sqliteVdbeOp3(v, OP_Halt, SQLITE_CONSTRAINT, onError,
"PRIMARY KEY must be unique", P3_STATIC);
break;
}
case OE_Replace: {
sqliteGenerateRowIndexDelete(pParse->db, v, pTab, base, 0);
if( isUpdate ){
sqliteVdbeAddOp(v, OP_Dup, nCol+hasTwoRecnos, 1);
sqliteVdbeAddOp(v, OP_MoveTo, base, 0);
}
seenReplace = 1;
break;
}
case OE_Ignore: {
assert( seenReplace==0 );
sqliteVdbeAddOp(v, OP_Pop, nCol+1+hasTwoRecnos, 0);
sqliteVdbeAddOp(v, OP_Goto, 0, ignoreDest);
break;
}
}
contAddr = sqliteVdbeCurrentAddr(v);
sqliteVdbeChangeP2(v, jumpInst2, contAddr);
if( isUpdate ){
sqliteVdbeChangeP2(v, jumpInst1, contAddr);
sqliteVdbeAddOp(v, OP_Dup, nCol+1, 1);
sqliteVdbeAddOp(v, OP_MoveTo, base, 0);
}
}
/* Test all UNIQUE constraints by creating entries for each UNIQUE
** index and making sure that duplicate entries do not already exist.
** Add the new records to the indices as we go.
*/
extra = -1;
for(iCur=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, iCur++){
if( aIdxUsed && aIdxUsed[iCur]==0 ) continue; /* Skip unused indices */
extra++;
/* Create a key for accessing the index entry */
sqliteVdbeAddOp(v, OP_Dup, nCol+extra, 1);
for(i=0; i<pIdx->nColumn; i++){
int idx = pIdx->aiColumn[i];
if( idx==pTab->iPKey ){
sqliteVdbeAddOp(v, OP_Dup, i+extra+nCol+1, 1);
}else{
sqliteVdbeAddOp(v, OP_Dup, i+extra+nCol-idx, 1);
}
}
jumpInst1 = sqliteVdbeAddOp(v, OP_MakeIdxKey, pIdx->nColumn, 0);
if( pParse->db->file_format>=4 ) sqliteAddIdxKeyType(v, pIdx);
/* Find out what action to take in case there is an indexing conflict */
onError = pIdx->onError;
if( onError==OE_None ) continue; /* pIdx is not a UNIQUE index */
if( overrideError!=OE_Default ){
onError = overrideError;
}else if( pParse->db->onError!=OE_Default ){
onError = pParse->db->onError;
}else if( onError==OE_Default ){
onError = OE_Abort;
}
if( seenReplace ){
if( onError==OE_Ignore ) onError = OE_Replace;
else if( onError==OE_Fail ) onError = OE_Abort;
}
/* Check to see if the new index entry will be unique */
sqliteVdbeAddOp(v, OP_Dup, extra+nCol+1+hasTwoRecnos, 1);
jumpInst2 = sqliteVdbeAddOp(v, OP_IsUnique, base+iCur+1, 0);
/* Generate code that executes if the new index entry is not unique */
switch( onError ){
case OE_Rollback:
case OE_Abort:
case OE_Fail: {
int j, n1, n2;
char zErrMsg[200];
strcpy(zErrMsg, pIdx->nColumn>1 ? "columns " : "column ");
n1 = strlen(zErrMsg);
for(j=0; j<pIdx->nColumn && n1<sizeof(zErrMsg)-30; j++){
char *zCol = pTab->aCol[pIdx->aiColumn[j]].zName;
n2 = strlen(zCol);
if( j>0 ){
strcpy(&zErrMsg[n1], ", ");
n1 += 2;
}
if( n1+n2>sizeof(zErrMsg)-30 ){
strcpy(&zErrMsg[n1], "...");
n1 += 3;
break;
}else{
strcpy(&zErrMsg[n1], zCol);
n1 += n2;
}
}
strcpy(&zErrMsg[n1],
pIdx->nColumn>1 ? " are not unique" : " is not unique");
sqliteVdbeOp3(v, OP_Halt, SQLITE_CONSTRAINT, onError, zErrMsg, 0);
break;
}
case OE_Ignore: {
assert( seenReplace==0 );
sqliteVdbeAddOp(v, OP_Pop, nCol+extra+3+hasTwoRecnos, 0);
sqliteVdbeAddOp(v, OP_Goto, 0, ignoreDest);
break;
}
case OE_Replace: {
sqliteGenerateRowDelete(pParse->db, v, pTab, base, 0);
if( isUpdate ){
sqliteVdbeAddOp(v, OP_Dup, nCol+extra+1+hasTwoRecnos, 1);
sqliteVdbeAddOp(v, OP_MoveTo, base, 0);
}
seenReplace = 1;
break;
}
default: assert(0);
}
contAddr = sqliteVdbeCurrentAddr(v);
#if NULL_DISTINCT_FOR_UNIQUE
sqliteVdbeChangeP2(v, jumpInst1, contAddr);
#endif
sqliteVdbeChangeP2(v, jumpInst2, contAddr);
}
}
/*
** Generate the beginning of the loop used for WHERE clause processing.
** The return value is a pointer to an (opaque) structure that contains
** information needed to terminate the loop. Later, the calling routine
** should invoke sqliteWhereEnd() with the return value of this function
** in order to complete the WHERE clause processing.
**
** If an error occurs, this routine returns NULL.
**
** The basic idea is to do a nested loop, one loop for each table in
** the FROM clause of a select. (INSERT and UPDATE statements are the
** same as a SELECT with only a single table in the FROM clause.) For
** example, if the SQL is this:
**
** SELECT * FROM t1, t2, t3 WHERE ...;
**
** Then the code generated is conceptually like the following:
**
** foreach row1 in t1 do \ Code generated
** foreach row2 in t2 do |-- by sqliteWhereBegin()
** foreach row3 in t3 do /
** ...
** end \ Code generated
** end |-- by sqliteWhereEnd()
** end /
**
** There are Btree cursors associated with each table. t1 uses cursor
** number pTabList->a[0].iCursor. t2 uses the cursor pTabList->a[1].iCursor.
** And so forth. This routine generates code to open those VDBE cursors
** and sqliteWhereEnd() generates the code to close them.
**
** If the WHERE clause is empty, the foreach loops must each scan their
** entire tables. Thus a three-way join is an O(N^3) operation. But if
** the tables have indices and there are terms in the WHERE clause that
** refer to those indices, a complete table scan can be avoided and the
** code will run much faster. Most of the work of this routine is checking
** to see if there are indices that can be used to speed up the loop.
**
** Terms of the WHERE clause are also used to limit which rows actually
** make it to the "..." in the middle of the loop. After each "foreach",
** terms of the WHERE clause that use only terms in that loop and outer
** loops are evaluated and if false a jump is made around all subsequent
** inner loops (or around the "..." if the test occurs within the inner-
** most loop)
**
** OUTER JOINS
**
** An outer join of tables t1 and t2 is conceptally coded as follows:
**
** foreach row1 in t1 do
** flag = 0
** foreach row2 in t2 do
** start:
** ...
** flag = 1
** end
** if flag==0 then
** move the row2 cursor to a null row
** goto start
** fi
** end
**
** ORDER BY CLAUSE PROCESSING
**
** *ppOrderBy is a pointer to the ORDER BY clause of a SELECT statement,
** if there is one. If there is no ORDER BY clause or if this routine
** is called from an UPDATE or DELETE statement, then ppOrderBy is NULL.
**
** If an index can be used so that the natural output order of the table
** scan is correct for the ORDER BY clause, then that index is used and
** *ppOrderBy is set to NULL. This is an optimization that prevents an
** unnecessary sort of the result set if an index appropriate for the
** ORDER BY clause already exists.
**
** If the where clause loops cannot be arranged to provide the correct
** output order, then the *ppOrderBy is unchanged.
*/
WhereInfo *sqliteWhereBegin(
Parse *pParse, /* The parser context */
SrcList *pTabList, /* A list of all tables to be scanned */
Expr *pWhere, /* The WHERE clause */
int pushKey, /* If TRUE, leave the table key on the stack */
ExprList **ppOrderBy /* An ORDER BY clause, or NULL */
) {
int i; /* Loop counter */
WhereInfo *pWInfo; /* Will become the return value of this function */
Vdbe *v = pParse->pVdbe; /* The virtual database engine */
int brk, cont = 0; /* Addresses used during code generation */
int nExpr; /* Number of subexpressions in the WHERE clause */
int loopMask; /* One bit set for each outer loop */
int haveKey; /* True if KEY is on the stack */
ExprMaskSet maskSet; /* The expression mask set */
int iDirectEq[32]; /* Term of the form ROWID==X for the N-th table */
int iDirectLt[32]; /* Term of the form ROWID<X or ROWID<=X */
int iDirectGt[32]; /* Term of the form ROWID>X or ROWID>=X */
ExprInfo aExpr[101]; /* The WHERE clause is divided into these expressions */
/* pushKey is only allowed if there is a single table (as in an INSERT or
** UPDATE statement)
*/
assert( pushKey==0 || pTabList->nSrc==1 );
/* Split the WHERE clause into separate subexpressions where each
** subexpression is separated by an AND operator. If the aExpr[]
** array fills up, the last entry might point to an expression which
** contains additional unfactored AND operators.
*/
initMaskSet(&maskSet);
memset(aExpr, 0, sizeof(aExpr));
nExpr = exprSplit(ARRAYSIZE(aExpr), aExpr, pWhere);
if( nExpr==ARRAYSIZE(aExpr) ) {
char zBuf[50];
sprintf(zBuf, "%d", (int)ARRAYSIZE(aExpr)-1);
sqliteSetString(&pParse->zErrMsg, "WHERE clause too complex - no more "
"than ", zBuf, " terms allowed", (char*)0);
pParse->nErr++;
return 0;
}
/* Allocate and initialize the WhereInfo structure that will become the
** return value.
*/
pWInfo = sqliteMalloc( sizeof(WhereInfo) + pTabList->nSrc*sizeof(WhereLevel));
if( sqlite_malloc_failed ) {
sqliteFree(pWInfo);
return 0;
}
pWInfo->pParse = pParse;
pWInfo->pTabList = pTabList;
pWInfo->peakNTab = pWInfo->savedNTab = pParse->nTab;
pWInfo->iBreak = sqliteVdbeMakeLabel(v);
/* Special case: a WHERE clause that is constant. Evaluate the
** expression and either jump over all of the code or fall thru.
*/
if( pWhere && (pTabList->nSrc==0 || sqliteExprIsConstant(pWhere)) ) {
sqliteExprIfFalse(pParse, pWhere, pWInfo->iBreak, 1);
pWhere = 0;
}
/* Analyze all of the subexpressions.
*/
for(i=0; i<nExpr; i++) {
exprAnalyze(&maskSet, &aExpr[i]);
/* If we are executing a trigger body, remove all references to
** new.* and old.* tables from the prerequisite masks.
*/
if( pParse->trigStack ) {
int x;
if( (x = pParse->trigStack->newIdx) >= 0 ) {
int mask = ~getMask(&maskSet, x);
aExpr[i].prereqRight &= mask;
aExpr[i].prereqLeft &= mask;
aExpr[i].prereqAll &= mask;
}
if( (x = pParse->trigStack->oldIdx) >= 0 ) {
int mask = ~getMask(&maskSet, x);
aExpr[i].prereqRight &= mask;
aExpr[i].prereqLeft &= mask;
aExpr[i].prereqAll &= mask;
}
}
}
/* Figure out what index to use (if any) for each nested loop.
** Make pWInfo->a[i].pIdx point to the index to use for the i-th nested
** loop where i==0 is the outer loop and i==pTabList->nSrc-1 is the inner
** loop.
**
** If terms exist that use the ROWID of any table, then set the
** iDirectEq[], iDirectLt[], or iDirectGt[] elements for that table
** to the index of the term containing the ROWID. We always prefer
** to use a ROWID which can directly access a table rather than an
** index which requires reading an index first to get the rowid then
** doing a second read of the actual database table.
**
** Actually, if there are more than 32 tables in the join, only the
** first 32 tables are candidates for indices. This is (again) due
** to the limit of 32 bits in an integer bitmask.
*/
loopMask = 0;
for(i=0; i<pTabList->nSrc && i<ARRAYSIZE(iDirectEq); i++) {
int j;
int iCur = pTabList->a[i].iCursor; /* The cursor for this table */
int mask = getMask(&maskSet, iCur); /* Cursor mask for this table */
Table *pTab = pTabList->a[i].pTab;
Index *pIdx;
Index *pBestIdx = 0;
int bestScore = 0;
/* Check to see if there is an expression that uses only the
** ROWID field of this table. For terms of the form ROWID==expr
** set iDirectEq[i] to the index of the term. For terms of the
** form ROWID<expr or ROWID<=expr set iDirectLt[i] to the term index.
** For terms like ROWID>expr or ROWID>=expr set iDirectGt[i].
**
** (Added:) Treat ROWID IN expr like ROWID=expr.
*/
pWInfo->a[i].iCur = -1;
iDirectEq[i] = -1;
iDirectLt[i] = -1;
iDirectGt[i] = -1;
for(j=0; j<nExpr; j++) {
if( aExpr[j].idxLeft==iCur && aExpr[j].p->pLeft->iColumn<0
&& (aExpr[j].prereqRight & loopMask)==aExpr[j].prereqRight ) {
switch( aExpr[j].p->op ) {
case TK_IN:
case TK_EQ:
iDirectEq[i] = j;
break;
case TK_LE:
case TK_LT:
iDirectLt[i] = j;
break;
case TK_GE:
case TK_GT:
iDirectGt[i] = j;
break;
}
}
if( aExpr[j].idxRight==iCur && aExpr[j].p->pRight->iColumn<0
&& (aExpr[j].prereqLeft & loopMask)==aExpr[j].prereqLeft ) {
switch( aExpr[j].p->op ) {
case TK_EQ:
iDirectEq[i] = j;
break;
case TK_LE:
case TK_LT:
iDirectGt[i] = j;
break;
case TK_GE:
case TK_GT:
iDirectLt[i] = j;
break;
}
}
}
if( iDirectEq[i]>=0 ) {
loopMask |= mask;
pWInfo->a[i].pIdx = 0;
continue;
}
/* Do a search for usable indices. Leave pBestIdx pointing to
** the "best" index. pBestIdx is left set to NULL if no indices
** are usable.
**
** The best index is determined as follows. For each of the
** left-most terms that is fixed by an equality operator, add
** 8 to the score. The right-most term of the index may be
** constrained by an inequality. Add 1 if for an "x<..." constraint
** and add 2 for an "x>..." constraint. Chose the index that
** gives the best score.
**
** This scoring system is designed so that the score can later be
** used to determine how the index is used. If the score&7 is 0
** then all constraints are equalities. If score&1 is not 0 then
** there is an inequality used as a termination key. (ex: "x<...")
** If score&2 is not 0 then there is an inequality used as the
** start key. (ex: "x>..."). A score or 4 is the special case
** of an IN operator constraint. (ex: "x IN ...").
**
** The IN operator (as in "<expr> IN (...)") is treated the same as
** an equality comparison except that it can only be used on the
** left-most column of an index and other terms of the WHERE clause
** cannot be used in conjunction with the IN operator to help satisfy
** other columns of the index.
*/
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext) {
int eqMask = 0; /* Index columns covered by an x=... term */
int ltMask = 0; /* Index columns covered by an x<... term */
int gtMask = 0; /* Index columns covered by an x>... term */
int inMask = 0; /* Index columns covered by an x IN .. term */
int nEq, m, score;
if( pIdx->nColumn>32 ) continue; /* Ignore indices too many columns */
for(j=0; j<nExpr; j++) {
if( aExpr[j].idxLeft==iCur
&& (aExpr[j].prereqRight & loopMask)==aExpr[j].prereqRight ) {
int iColumn = aExpr[j].p->pLeft->iColumn;
int k;
for(k=0; k<pIdx->nColumn; k++) {
if( pIdx->aiColumn[k]==iColumn ) {
switch( aExpr[j].p->op ) {
case TK_IN: {
if( k==0 ) inMask |= 1;
break;
}
case TK_EQ: {
eqMask |= 1<<k;
break;
}
case TK_LE:
case TK_LT: {
ltMask |= 1<<k;
break;
}
case TK_GE:
case TK_GT: {
gtMask |= 1<<k;
break;
}
default: {
/* CANT_HAPPEN */
assert( 0 );
break;
}
}
break;
}
}
}
if( aExpr[j].idxRight==iCur
&& (aExpr[j].prereqLeft & loopMask)==aExpr[j].prereqLeft ) {
int iColumn = aExpr[j].p->pRight->iColumn;
int k;
for(k=0; k<pIdx->nColumn; k++) {
if( pIdx->aiColumn[k]==iColumn ) {
switch( aExpr[j].p->op ) {
case TK_EQ: {
eqMask |= 1<<k;
break;
}
case TK_LE:
case TK_LT: {
gtMask |= 1<<k;
break;
}
case TK_GE:
case TK_GT: {
ltMask |= 1<<k;
break;
}
default: {
/* CANT_HAPPEN */
assert( 0 );
break;
}
}
break;
}
}
}
}
/* The following loop ends with nEq set to the number of columns
** on the left of the index with == constraints.
*/
for(nEq=0; nEq<pIdx->nColumn; nEq++) {
m = (1<<(nEq+1))-1;
if( (m & eqMask)!=m ) break;
}
score = nEq*8; /* Base score is 8 times number of == constraints */
m = 1<<nEq;
if( m & ltMask ) score++; /* Increase score for a < constraint */
if( m & gtMask ) score+=2; /* Increase score for a > constraint */
if( score==0 && inMask ) score = 4; /* Default score for IN constraint */
if( score>bestScore ) {
pBestIdx = pIdx;
bestScore = score;
}
}
pWInfo->a[i].pIdx = pBestIdx;
pWInfo->a[i].score = bestScore;
pWInfo->a[i].bRev = 0;
loopMask |= mask;
if( pBestIdx ) {
pWInfo->a[i].iCur = pParse->nTab++;
pWInfo->peakNTab = pParse->nTab;
}
}
/* Check to see if the ORDER BY clause is or can be satisfied by the
** use of an index on the first table.
*/
if( ppOrderBy && *ppOrderBy && pTabList->nSrc>0 ) {
Index *pSortIdx;
Index *pIdx;
Table *pTab;
int bRev = 0;
pTab = pTabList->a[0].pTab;
pIdx = pWInfo->a[0].pIdx;
if( pIdx && pWInfo->a[0].score==4 ) {
/* If there is already an IN index on the left-most table,
** it will not give the correct sort order.
** So, pretend that no suitable index is found.
*/
pSortIdx = 0;
} else if( iDirectEq[0]>=0 || iDirectLt[0]>=0 || iDirectGt[0]>=0 ) {
/* If the left-most column is accessed using its ROWID, then do
** not try to sort by index.
*/
pSortIdx = 0;
} else {
int nEqCol = (pWInfo->a[0].score+4)/8;
pSortIdx = findSortingIndex(pTab, pTabList->a[0].iCursor,
*ppOrderBy, pIdx, nEqCol, &bRev);
}
if( pSortIdx && (pIdx==0 || pIdx==pSortIdx) ) {
if( pIdx==0 ) {
pWInfo->a[0].pIdx = pSortIdx;
pWInfo->a[0].iCur = pParse->nTab++;
pWInfo->peakNTab = pParse->nTab;
}
pWInfo->a[0].bRev = bRev;
*ppOrderBy = 0;
}
}
/* Open all tables in the pTabList and all indices used by those tables.
*/
for(i=0; i<pTabList->nSrc; i++) {
Table *pTab;
pTab = pTabList->a[i].pTab;
if( pTab->isTransient || pTab->pSelect ) continue;
sqliteVdbeAddOp(v, OP_Integer, pTab->iDb, 0);
sqliteVdbeAddOp(v, OP_OpenRead, pTabList->a[i].iCursor, pTab->tnum);
sqliteVdbeChangeP3(v, -1, pTab->zName, P3_STATIC);
sqliteCodeVerifySchema(pParse, pTab->iDb);
if( pWInfo->a[i].pIdx!=0 ) {
sqliteVdbeAddOp(v, OP_Integer, pWInfo->a[i].pIdx->iDb, 0);
sqliteVdbeAddOp(v, OP_OpenRead,
pWInfo->a[i].iCur, pWInfo->a[i].pIdx->tnum);
sqliteVdbeChangeP3(v, -1, pWInfo->a[i].pIdx->zName, P3_STATIC);
}
}
/* Generate the code to do the search
*/
loopMask = 0;
for(i=0; i<pTabList->nSrc; i++) {
int j, k;
int iCur = pTabList->a[i].iCursor;
Index *pIdx;
WhereLevel *pLevel = &pWInfo->a[i];
/* If this is the right table of a LEFT OUTER JOIN, allocate and
** initialize a memory cell that records if this table matches any
** row of the left table of the join.
*/
if( i>0 && (pTabList->a[i-1].jointype & JT_LEFT)!=0 ) {
if( !pParse->nMem ) pParse->nMem++;
pLevel->iLeftJoin = pParse->nMem++;
sqliteVdbeAddOp(v, OP_String, 0, 0);
sqliteVdbeAddOp(v, OP_MemStore, pLevel->iLeftJoin, 1);
}
pIdx = pLevel->pIdx;
pLevel->inOp = OP_Noop;
if( i<ARRAYSIZE(iDirectEq) && iDirectEq[i]>=0 ) {
/* Case 1: We can directly reference a single row using an
** equality comparison against the ROWID field. Or
** we reference multiple rows using a "rowid IN (...)"
** construct.
*/
k = iDirectEq[i];
assert( k<nExpr );
assert( aExpr[k].p!=0 );
assert( aExpr[k].idxLeft==iCur || aExpr[k].idxRight==iCur );
brk = pLevel->brk = sqliteVdbeMakeLabel(v);
if( aExpr[k].idxLeft==iCur ) {
Expr *pX = aExpr[k].p;
if( pX->op!=TK_IN ) {
sqliteExprCode(pParse, aExpr[k].p->pRight);
} else if( pX->pList ) {
sqliteVdbeAddOp(v, OP_SetFirst, pX->iTable, brk);
pLevel->inOp = OP_SetNext;
pLevel->inP1 = pX->iTable;
pLevel->inP2 = sqliteVdbeCurrentAddr(v);
} else {
assert( pX->pSelect );
sqliteVdbeAddOp(v, OP_Rewind, pX->iTable, brk);
sqliteVdbeAddOp(v, OP_KeyAsData, pX->iTable, 1);
pLevel->inP2 = sqliteVdbeAddOp(v, OP_FullKey, pX->iTable, 0);
pLevel->inOp = OP_Next;
pLevel->inP1 = pX->iTable;
}
} else {
sqliteExprCode(pParse, aExpr[k].p->pLeft);
}
aExpr[k].p = 0;
cont = pLevel->cont = sqliteVdbeMakeLabel(v);
sqliteVdbeAddOp(v, OP_MustBeInt, 1, brk);
haveKey = 0;
sqliteVdbeAddOp(v, OP_NotExists, iCur, brk);
pLevel->op = OP_Noop;
} else if( pIdx!=0 && pLevel->score>0 && pLevel->score%4==0 ) {
/* Case 2: There is an index and all terms of the WHERE clause that
** refer to the index use the "==" or "IN" operators.
*/
int start;
int testOp;
int nColumn = (pLevel->score+4)/8;
brk = pLevel->brk = sqliteVdbeMakeLabel(v);
for(j=0; j<nColumn; j++) {
for(k=0; k<nExpr; k++) {
Expr *pX = aExpr[k].p;
if( pX==0 ) continue;
if( aExpr[k].idxLeft==iCur
&& (aExpr[k].prereqRight & loopMask)==aExpr[k].prereqRight
&& pX->pLeft->iColumn==pIdx->aiColumn[j]
) {
if( pX->op==TK_EQ ) {
sqliteExprCode(pParse, pX->pRight);
aExpr[k].p = 0;
break;
}
if( pX->op==TK_IN && nColumn==1 ) {
if( pX->pList ) {
sqliteVdbeAddOp(v, OP_SetFirst, pX->iTable, brk);
pLevel->inOp = OP_SetNext;
pLevel->inP1 = pX->iTable;
pLevel->inP2 = sqliteVdbeCurrentAddr(v);
} else {
assert( pX->pSelect );
sqliteVdbeAddOp(v, OP_Rewind, pX->iTable, brk);
sqliteVdbeAddOp(v, OP_KeyAsData, pX->iTable, 1);
pLevel->inP2 = sqliteVdbeAddOp(v, OP_FullKey, pX->iTable, 0);
pLevel->inOp = OP_Next;
pLevel->inP1 = pX->iTable;
}
aExpr[k].p = 0;
break;
}
}
if( aExpr[k].idxRight==iCur
&& aExpr[k].p->op==TK_EQ
&& (aExpr[k].prereqLeft & loopMask)==aExpr[k].prereqLeft
&& aExpr[k].p->pRight->iColumn==pIdx->aiColumn[j]
) {
sqliteExprCode(pParse, aExpr[k].p->pLeft);
aExpr[k].p = 0;
break;
}
}
}
pLevel->iMem = pParse->nMem++;
cont = pLevel->cont = sqliteVdbeMakeLabel(v);
sqliteVdbeAddOp(v, OP_NotNull, -nColumn, sqliteVdbeCurrentAddr(v)+3);
sqliteVdbeAddOp(v, OP_Pop, nColumn, 0);
sqliteVdbeAddOp(v, OP_Goto, 0, brk);
sqliteVdbeAddOp(v, OP_MakeKey, nColumn, 0);
sqliteAddIdxKeyType(v, pIdx);
if( nColumn==pIdx->nColumn || pLevel->bRev ) {
sqliteVdbeAddOp(v, OP_MemStore, pLevel->iMem, 0);
testOp = OP_IdxGT;
} else {
sqliteVdbeAddOp(v, OP_Dup, 0, 0);
sqliteVdbeAddOp(v, OP_IncrKey, 0, 0);
sqliteVdbeAddOp(v, OP_MemStore, pLevel->iMem, 1);
testOp = OP_IdxGE;
}
if( pLevel->bRev ) {
/* Scan in reverse order */
sqliteVdbeAddOp(v, OP_IncrKey, 0, 0);
sqliteVdbeAddOp(v, OP_MoveLt, pLevel->iCur, brk);
start = sqliteVdbeAddOp(v, OP_MemLoad, pLevel->iMem, 0);
sqliteVdbeAddOp(v, OP_IdxLT, pLevel->iCur, brk);
pLevel->op = OP_Prev;
} else {
/* Scan in the forward order */
sqliteVdbeAddOp(v, OP_MoveTo, pLevel->iCur, brk);
start = sqliteVdbeAddOp(v, OP_MemLoad, pLevel->iMem, 0);
sqliteVdbeAddOp(v, testOp, pLevel->iCur, brk);
pLevel->op = OP_Next;
}
sqliteVdbeAddOp(v, OP_RowKey, pLevel->iCur, 0);
sqliteVdbeAddOp(v, OP_IdxIsNull, nColumn, cont);
sqliteVdbeAddOp(v, OP_IdxRecno, pLevel->iCur, 0);
if( i==pTabList->nSrc-1 && pushKey ) {
haveKey = 1;
} else {
sqliteVdbeAddOp(v, OP_MoveTo, iCur, 0);
haveKey = 0;
}
pLevel->p1 = pLevel->iCur;
pLevel->p2 = start;
} else if( i<ARRAYSIZE(iDirectLt) && (iDirectLt[i]>=0 || iDirectGt[i]>=0) ) {
/* Case 3: We have an inequality comparison against the ROWID field.
*/
int testOp = OP_Noop;
int start;
brk = pLevel->brk = sqliteVdbeMakeLabel(v);
cont = pLevel->cont = sqliteVdbeMakeLabel(v);
if( iDirectGt[i]>=0 ) {
k = iDirectGt[i];
assert( k<nExpr );
assert( aExpr[k].p!=0 );
assert( aExpr[k].idxLeft==iCur || aExpr[k].idxRight==iCur );
if( aExpr[k].idxLeft==iCur ) {
sqliteExprCode(pParse, aExpr[k].p->pRight);
} else {
sqliteExprCode(pParse, aExpr[k].p->pLeft);
}
sqliteVdbeAddOp(v, OP_ForceInt,
aExpr[k].p->op==TK_LT || aExpr[k].p->op==TK_GT, brk);
sqliteVdbeAddOp(v, OP_MoveTo, iCur, brk);
aExpr[k].p = 0;
} else {
sqliteVdbeAddOp(v, OP_Rewind, iCur, brk);
}
if( iDirectLt[i]>=0 ) {
k = iDirectLt[i];
assert( k<nExpr );
assert( aExpr[k].p!=0 );
assert( aExpr[k].idxLeft==iCur || aExpr[k].idxRight==iCur );
if( aExpr[k].idxLeft==iCur ) {
sqliteExprCode(pParse, aExpr[k].p->pRight);
} else {
sqliteExprCode(pParse, aExpr[k].p->pLeft);
}
/* sqliteVdbeAddOp(v, OP_MustBeInt, 0, sqliteVdbeCurrentAddr(v)+1); */
pLevel->iMem = pParse->nMem++;
sqliteVdbeAddOp(v, OP_MemStore, pLevel->iMem, 1);
if( aExpr[k].p->op==TK_LT || aExpr[k].p->op==TK_GT ) {
testOp = OP_Ge;
} else {
testOp = OP_Gt;
}
aExpr[k].p = 0;
}
start = sqliteVdbeCurrentAddr(v);
pLevel->op = OP_Next;
pLevel->p1 = iCur;
pLevel->p2 = start;
if( testOp!=OP_Noop ) {
sqliteVdbeAddOp(v, OP_Recno, iCur, 0);
sqliteVdbeAddOp(v, OP_MemLoad, pLevel->iMem, 0);
sqliteVdbeAddOp(v, testOp, 0, brk);
}
haveKey = 0;
} else if( pIdx==0 ) {
/* Case 4: There is no usable index. We must do a complete
** scan of the entire database table.
*/
int start;
brk = pLevel->brk = sqliteVdbeMakeLabel(v);
cont = pLevel->cont = sqliteVdbeMakeLabel(v);
sqliteVdbeAddOp(v, OP_Rewind, iCur, brk);
start = sqliteVdbeCurrentAddr(v);
pLevel->op = OP_Next;
pLevel->p1 = iCur;
pLevel->p2 = start;
haveKey = 0;
} else {
/* Case 5: The WHERE clause term that refers to the right-most
** column of the index is an inequality. For example, if
** the index is on (x,y,z) and the WHERE clause is of the
** form "x=5 AND y<10" then this case is used. Only the
** right-most column can be an inequality - the rest must
** use the "==" operator.
**
** This case is also used when there are no WHERE clause
** constraints but an index is selected anyway, in order
** to force the output order to conform to an ORDER BY.
*/
int score = pLevel->score;
int nEqColumn = score/8;
int start;
int leFlag, geFlag;
int testOp;
/* Evaluate the equality constraints
*/
for(j=0; j<nEqColumn; j++) {
for(k=0; k<nExpr; k++) {
if( aExpr[k].p==0 ) continue;
if( aExpr[k].idxLeft==iCur
&& aExpr[k].p->op==TK_EQ
&& (aExpr[k].prereqRight & loopMask)==aExpr[k].prereqRight
&& aExpr[k].p->pLeft->iColumn==pIdx->aiColumn[j]
) {
sqliteExprCode(pParse, aExpr[k].p->pRight);
aExpr[k].p = 0;
break;
}
if( aExpr[k].idxRight==iCur
&& aExpr[k].p->op==TK_EQ
&& (aExpr[k].prereqLeft & loopMask)==aExpr[k].prereqLeft
&& aExpr[k].p->pRight->iColumn==pIdx->aiColumn[j]
) {
sqliteExprCode(pParse, aExpr[k].p->pLeft);
aExpr[k].p = 0;
break;
}
}
}
/* Duplicate the equality term values because they will all be
** used twice: once to make the termination key and once to make the
** start key.
*/
for(j=0; j<nEqColumn; j++) {
sqliteVdbeAddOp(v, OP_Dup, nEqColumn-1, 0);
}
/* Labels for the beginning and end of the loop
*/
cont = pLevel->cont = sqliteVdbeMakeLabel(v);
brk = pLevel->brk = sqliteVdbeMakeLabel(v);
/* Generate the termination key. This is the key value that
** will end the search. There is no termination key if there
** are no equality terms and no "X<..." term.
**
** 2002-Dec-04: On a reverse-order scan, the so-called "termination"
** key computed here really ends up being the start key.
*/
if( (score & 1)!=0 ) {
for(k=0; k<nExpr; k++) {
Expr *pExpr = aExpr[k].p;
if( pExpr==0 ) continue;
if( aExpr[k].idxLeft==iCur
&& (pExpr->op==TK_LT || pExpr->op==TK_LE)
&& (aExpr[k].prereqRight & loopMask)==aExpr[k].prereqRight
&& pExpr->pLeft->iColumn==pIdx->aiColumn[j]
) {
sqliteExprCode(pParse, pExpr->pRight);
leFlag = pExpr->op==TK_LE;
aExpr[k].p = 0;
break;
}
if( aExpr[k].idxRight==iCur
&& (pExpr->op==TK_GT || pExpr->op==TK_GE)
&& (aExpr[k].prereqLeft & loopMask)==aExpr[k].prereqLeft
&& pExpr->pRight->iColumn==pIdx->aiColumn[j]
) {
sqliteExprCode(pParse, pExpr->pLeft);
leFlag = pExpr->op==TK_GE;
aExpr[k].p = 0;
break;
}
}
testOp = OP_IdxGE;
} else {
testOp = nEqColumn>0 ? OP_IdxGE : OP_Noop;
leFlag = 1;
}
if( testOp!=OP_Noop ) {
int nCol = nEqColumn + (score & 1);
pLevel->iMem = pParse->nMem++;
sqliteVdbeAddOp(v, OP_NotNull, -nCol, sqliteVdbeCurrentAddr(v)+3);
sqliteVdbeAddOp(v, OP_Pop, nCol, 0);
sqliteVdbeAddOp(v, OP_Goto, 0, brk);
sqliteVdbeAddOp(v, OP_MakeKey, nCol, 0);
sqliteAddIdxKeyType(v, pIdx);
if( leFlag ) {
sqliteVdbeAddOp(v, OP_IncrKey, 0, 0);
}
if( pLevel->bRev ) {
sqliteVdbeAddOp(v, OP_MoveLt, pLevel->iCur, brk);
} else {
sqliteVdbeAddOp(v, OP_MemStore, pLevel->iMem, 1);
}
} else if( pLevel->bRev ) {
sqliteVdbeAddOp(v, OP_Last, pLevel->iCur, brk);
}
/* Generate the start key. This is the key that defines the lower
** bound on the search. There is no start key if there are no
** equality terms and if there is no "X>..." term. In
** that case, generate a "Rewind" instruction in place of the
** start key search.
**
** 2002-Dec-04: In the case of a reverse-order search, the so-called
** "start" key really ends up being used as the termination key.
*/
if( (score & 2)!=0 ) {
for(k=0; k<nExpr; k++) {
Expr *pExpr = aExpr[k].p;
if( pExpr==0 ) continue;
if( aExpr[k].idxLeft==iCur
&& (pExpr->op==TK_GT || pExpr->op==TK_GE)
&& (aExpr[k].prereqRight & loopMask)==aExpr[k].prereqRight
&& pExpr->pLeft->iColumn==pIdx->aiColumn[j]
) {
sqliteExprCode(pParse, pExpr->pRight);
geFlag = pExpr->op==TK_GE;
aExpr[k].p = 0;
break;
}
if( aExpr[k].idxRight==iCur
&& (pExpr->op==TK_LT || pExpr->op==TK_LE)
&& (aExpr[k].prereqLeft & loopMask)==aExpr[k].prereqLeft
&& pExpr->pRight->iColumn==pIdx->aiColumn[j]
) {
sqliteExprCode(pParse, pExpr->pLeft);
geFlag = pExpr->op==TK_LE;
aExpr[k].p = 0;
break;
}
}
} else {
geFlag = 1;
}
if( nEqColumn>0 || (score&2)!=0 ) {
int nCol = nEqColumn + ((score&2)!=0);
sqliteVdbeAddOp(v, OP_NotNull, -nCol, sqliteVdbeCurrentAddr(v)+3);
sqliteVdbeAddOp(v, OP_Pop, nCol, 0);
sqliteVdbeAddOp(v, OP_Goto, 0, brk);
sqliteVdbeAddOp(v, OP_MakeKey, nCol, 0);
sqliteAddIdxKeyType(v, pIdx);
if( !geFlag ) {
sqliteVdbeAddOp(v, OP_IncrKey, 0, 0);
}
if( pLevel->bRev ) {
pLevel->iMem = pParse->nMem++;
sqliteVdbeAddOp(v, OP_MemStore, pLevel->iMem, 1);
testOp = OP_IdxLT;
} else {
sqliteVdbeAddOp(v, OP_MoveTo, pLevel->iCur, brk);
}
} else if( pLevel->bRev ) {
testOp = OP_Noop;
} else {
sqliteVdbeAddOp(v, OP_Rewind, pLevel->iCur, brk);
}
/* Generate the the top of the loop. If there is a termination
** key we have to test for that key and abort at the top of the
** loop.
*/
start = sqliteVdbeCurrentAddr(v);
if( testOp!=OP_Noop ) {
sqliteVdbeAddOp(v, OP_MemLoad, pLevel->iMem, 0);
sqliteVdbeAddOp(v, testOp, pLevel->iCur, brk);
}
sqliteVdbeAddOp(v, OP_RowKey, pLevel->iCur, 0);
sqliteVdbeAddOp(v, OP_IdxIsNull, nEqColumn + (score & 1), cont);
sqliteVdbeAddOp(v, OP_IdxRecno, pLevel->iCur, 0);
if( i==pTabList->nSrc-1 && pushKey ) {
haveKey = 1;
} else {
sqliteVdbeAddOp(v, OP_MoveTo, iCur, 0);
haveKey = 0;
}
/* Record the instruction used to terminate the loop.
*/
pLevel->op = pLevel->bRev ? OP_Prev : OP_Next;
pLevel->p1 = pLevel->iCur;
pLevel->p2 = start;
}
loopMask |= getMask(&maskSet, iCur);
/* Insert code to test every subexpression that can be completely
** computed using the current set of tables.
*/
for(j=0; j<nExpr; j++) {
if( aExpr[j].p==0 ) continue;
if( (aExpr[j].prereqAll & loopMask)!=aExpr[j].prereqAll ) continue;
if( pLevel->iLeftJoin && !ExprHasProperty(aExpr[j].p,EP_FromJoin) ) {
continue;
}
if( haveKey ) {
haveKey = 0;
sqliteVdbeAddOp(v, OP_MoveTo, iCur, 0);
}
sqliteExprIfFalse(pParse, aExpr[j].p, cont, 1);
aExpr[j].p = 0;
}
brk = cont;
/* For a LEFT OUTER JOIN, generate code that will record the fact that
** at least one row of the right table has matched the left table.
*/
if( pLevel->iLeftJoin ) {
pLevel->top = sqliteVdbeCurrentAddr(v);
sqliteVdbeAddOp(v, OP_Integer, 1, 0);
sqliteVdbeAddOp(v, OP_MemStore, pLevel->iLeftJoin, 1);
for(j=0; j<nExpr; j++) {
if( aExpr[j].p==0 ) continue;
if( (aExpr[j].prereqAll & loopMask)!=aExpr[j].prereqAll ) continue;
if( haveKey ) {
/* Cannot happen. "haveKey" can only be true if pushKey is true
** an pushKey can only be true for DELETE and UPDATE and there are
** no outer joins with DELETE and UPDATE.
*/
haveKey = 0;
sqliteVdbeAddOp(v, OP_MoveTo, iCur, 0);
}
sqliteExprIfFalse(pParse, aExpr[j].p, cont, 1);
aExpr[j].p = 0;
}
}
}
pWInfo->iContinue = cont;
if( pushKey && !haveKey ) {
sqliteVdbeAddOp(v, OP_Recno, pTabList->a[0].iCursor, 0);
}
freeMaskSet(&maskSet);
return pWInfo;
}
/*
** 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 holding
** the table.
** pExpr->iTable Set to the cursor number for the table obtained
** from pSrcList.
** pExpr->iColumn Set to the column number within the table.
** pExpr->dataType Set to the appropriate data type for the column.
** 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 pDbToken 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 pTableToken is the name of the table (the "Y"). This
** value can be NULL if pDbToken is also NULL. If pTableToken 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 non-zero. Return zero on success.
*/
static int lookupName(
Parse *pParse, /* The parsing context */
Token *pDbToken, /* Name of the database containing table, or NULL */
Token *pTableToken, /* Name of table containing column, or NULL */
Token *pColumnToken, /* Name of the column. */
SrcList *pSrcList, /* List of tables used to resolve column names */
ExprList *pEList, /* List of expressions used to resolve "AS" */
Expr *pExpr /* Make this EXPR node point to the selected column */
){
char *zDb = 0; /* Name of the database. The "X" in X.Y.Z */
char *zTab = 0; /* Name of the table. The "Y" in X.Y.Z or Y.Z */
char *zCol = 0; /* Name of the column. The "Z" */
int i, j; /* Loop counters */
int cnt = 0; /* Number of matching column names */
int cntTab = 0; /* Number of matching table names */
sqlite *db = pParse->db; /* The database */
assert( pColumnToken && pColumnToken->z ); /* The Z in X.Y.Z cannot be NULL */
if( pDbToken && pDbToken->z ){
zDb = sqliteStrNDup(pDbToken->z, pDbToken->n);
sqliteDequote(zDb);
}else{
zDb = 0;
}
if( pTableToken && pTableToken->z ){
zTab = sqliteStrNDup(pTableToken->z, pTableToken->n);
sqliteDequote(zTab);
}else{
assert( zDb==0 );
zTab = 0;
}
zCol = sqliteStrNDup(pColumnToken->z, pColumnToken->n);
sqliteDequote(zCol);
if( sqlite_malloc_failed ){
return 1; /* Leak memory (zDb and zTab) if malloc fails */
}
assert( zTab==0 || pEList==0 );
pExpr->iTable = -1;
for(i=0; i<pSrcList->nSrc; i++){
struct SrcList_item *pItem = &pSrcList->a[i];
Table *pTab = pItem->pTab;
Column *pCol;
if( pTab==0 ) continue;
assert( pTab->nCol>0 );
if( zTab ){
if( pItem->zAlias ){
char *zTabName = pItem->zAlias;
if( sqliteStrICmp(zTabName, zTab)!=0 ) continue;
}else{
char *zTabName = pTab->zName;
if( zTabName==0 || sqliteStrICmp(zTabName, zTab)!=0 ) continue;
if( zDb!=0 && sqliteStrICmp(db->aDb[pTab->iDb].zName, zDb)!=0 ){
continue;
}
}
}
if( 0==(cntTab++) ){
pExpr->iTable = pItem->iCursor;
pExpr->iDb = pTab->iDb;
}
for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){
if( sqliteStrICmp(pCol->zName, zCol)==0 ){
cnt++;
pExpr->iTable = pItem->iCursor;
pExpr->iDb = pTab->iDb;
/* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */
pExpr->iColumn = j==pTab->iPKey ? -1 : j;
pExpr->dataType = pCol->sortOrder & SQLITE_SO_TYPEMASK;
break;
}
}
}
/* 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->trigStack!=0 ){
TriggerStack *pTriggerStack = pParse->trigStack;
Table *pTab = 0;
if( pTriggerStack->newIdx != -1 && sqliteStrICmp("new", zTab) == 0 ){
pExpr->iTable = pTriggerStack->newIdx;
assert( pTriggerStack->pTab );
pTab = pTriggerStack->pTab;
}else if( pTriggerStack->oldIdx != -1 && sqliteStrICmp("old", zTab) == 0 ){
pExpr->iTable = pTriggerStack->oldIdx;
assert( pTriggerStack->pTab );
pTab = pTriggerStack->pTab;
}
if( pTab ){
int j;
Column *pCol = pTab->aCol;
pExpr->iDb = pTab->iDb;
cntTab++;
for(j=0; j < pTab->nCol; j++, pCol++) {
if( sqliteStrICmp(pCol->zName, zCol)==0 ){
cnt++;
pExpr->iColumn = j==pTab->iPKey ? -1 : j;
pExpr->dataType = pCol->sortOrder & SQLITE_SO_TYPEMASK;
break;
}
}
}
}
/*
** Perhaps the name is a reference to the ROWID
*/
if( cnt==0 && cntTab==1 && sqliteIsRowid(zCol) ){
cnt = 1;
pExpr->iColumn = -1;
pExpr->dataType = SQLITE_SO_NUM;
}
/*
** 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!=0 ){
for(j=0; j<pEList->nExpr; j++){
char *zAs = pEList->a[j].zName;
if( zAs!=0 && sqliteStrICmp(zAs, zCol)==0 ){
assert( pExpr->pLeft==0 && pExpr->pRight==0 );
pExpr->op = TK_AS;
pExpr->iColumn = j;
pExpr->pLeft = sqliteExprDup(pEList->a[j].pExpr);
sqliteFree(zCol);
assert( zTab==0 && zDb==0 );
return 0;
}
}
}
/*
** 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.
*/
if( cnt==0 && zTab==0 && pColumnToken->z[0]=='"' ){
sqliteFree(zCol);
return 0;
}
/*
** 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 ){
char *z = 0;
char *zErr;
zErr = cnt==0 ? "no such column: %s" : "ambiguous column name: %s";
if( zDb ){
sqliteSetString(&z, zDb, ".", zTab, ".", zCol, 0);
}else if( zTab ){
sqliteSetString(&z, zTab, ".", zCol, 0);
}else{
z = sqliteStrDup(zCol);
}
sqliteErrorMsg(pParse, zErr, z);
sqliteFree(z);
}
/* Clean up and return
*/
sqliteFree(zDb);
sqliteFree(zTab);
sqliteFree(zCol);
sqliteExprDelete(pExpr->pLeft);
pExpr->pLeft = 0;
sqliteExprDelete(pExpr->pRight);
pExpr->pRight = 0;
pExpr->op = TK_COLUMN;
sqliteAuthRead(pParse, pExpr, pSrcList);
return cnt!=1;
}
