/*
** Generate VDBE code for the statements inside the body of a single
** trigger.
*/
static int codeTriggerProgram(
Parse *pParse, /* The parser context */
TriggerStep *pStepList, /* List of statements inside the trigger body */
int orconf /* Conflict algorithm. (OE_Abort, etc) */
){
TriggerStep *pStep;
Vdbe *v = pParse->pVdbe;
sqlite3 *db = pParse->db;
assert( pParse->pTriggerTab && pParse->pToplevel );
assert( pStepList );
assert( v!=0 );
for(pStep=pStepList; pStep; pStep=pStep->pNext){
/* Figure out the ON CONFLICT policy that will be used for this step
** of the trigger program. If the statement that caused this trigger
** to fire had an explicit ON CONFLICT, then use it. Otherwise, use
** the ON CONFLICT policy that was specified as part of the trigger
** step statement. Example:
**
** CREATE TRIGGER AFTER INSERT ON t1 BEGIN;
** INSERT OR REPLACE INTO t2 VALUES(new.a, new.b);
** END;
**
** INSERT INTO t1 ... ; -- insert into t2 uses REPLACE policy
** INSERT OR IGNORE INTO t1 ... ; -- insert into t2 uses IGNORE policy
*/
pParse->eOrconf = (orconf==OE_Default)?pStep->orconf:(u8)orconf;
assert( pParse->okConstFactor==0 );
switch( pStep->op ){
case TK_UPDATE: {
sqlite3Update(pParse,
targetSrcList(pParse, pStep),
sqlite3ExprListDup(db, pStep->pExprList, 0),
sqlite3ExprDup(db, pStep->pWhere, 0),
pParse->eOrconf
);
break;
}
case TK_INSERT: {
sqlite3Insert(pParse,
targetSrcList(pParse, pStep),
sqlite3SelectDup(db, pStep->pSelect, 0),
sqlite3IdListDup(db, pStep->pIdList),
pParse->eOrconf
);
break;
}
case TK_DELETE: {
sqlite3DeleteFrom(pParse,
targetSrcList(pParse, pStep),
sqlite3ExprDup(db, pStep->pWhere, 0)
);
break;
}
default: assert( pStep->op==TK_SELECT ); {
SelectDest sDest;
Select *pSelect = sqlite3SelectDup(db, pStep->pSelect, 0);
sqlite3SelectDestInit(&sDest, SRT_Discard, 0);
sqlite3Select(pParse, pSelect, &sDest);
sqlite3SelectDelete(db, pSelect);
break;
}
}
if( pStep->op!=TK_SELECT ){
sqlite3VdbeAddOp0(v, OP_ResetCount);
}
}
return 0;
}
/*
** Generate VDBE code for zero or more statements inside the body of a
** trigger.
*/
static int codeTriggerProgram(
Parse *pParse, /* The parser context */
TriggerStep *pStepList, /* List of statements inside the trigger body */
int orconfin /* Conflict algorithm. (OE_Abort, etc) */
){
TriggerStep * pTriggerStep = pStepList;
int orconf;
Vdbe *v = pParse->pVdbe;
assert( pTriggerStep!=0 );
assert( v!=0 );
sqlite3VdbeAddOp(v, OP_ContextPush, 0, 0);
VdbeComment((v, "# begin trigger %s", pStepList->pTrig->name));
while( pTriggerStep ){
orconf = (orconfin == OE_Default)?pTriggerStep->orconf:orconfin;
pParse->trigStack->orconf = orconf;
switch( pTriggerStep->op ){
case TK_SELECT: {
Select *ss = sqlite3SelectDup(pTriggerStep->pSelect);
if( ss ){
sqlite3SelectResolve(pParse, ss, 0);
sqlite3Select(pParse, ss, SRT_Discard, 0, 0, 0, 0, 0);
sqlite3SelectDelete(ss);
}
break;
}
case TK_UPDATE: {
SrcList *pSrc;
pSrc = targetSrcList(pParse, pTriggerStep);
sqlite3VdbeAddOp(v, OP_ResetCount, 0, 0);
sqlite3Update(pParse, pSrc,
sqlite3ExprListDup(pTriggerStep->pExprList),
sqlite3ExprDup(pTriggerStep->pWhere), orconf);
sqlite3VdbeAddOp(v, OP_ResetCount, 1, 0);
break;
}
case TK_INSERT: {
SrcList *pSrc;
pSrc = targetSrcList(pParse, pTriggerStep);
sqlite3VdbeAddOp(v, OP_ResetCount, 0, 0);
sqlite3Insert(pParse, pSrc,
sqlite3ExprListDup(pTriggerStep->pExprList),
sqlite3SelectDup(pTriggerStep->pSelect),
sqlite3IdListDup(pTriggerStep->pIdList), orconf);
sqlite3VdbeAddOp(v, OP_ResetCount, 1, 0);
break;
}
case TK_DELETE: {
SrcList *pSrc;
sqlite3VdbeAddOp(v, OP_ResetCount, 0, 0);
pSrc = targetSrcList(pParse, pTriggerStep);
sqlite3DeleteFrom(pParse, pSrc, sqlite3ExprDup(pTriggerStep->pWhere));
sqlite3VdbeAddOp(v, OP_ResetCount, 1, 0);
break;
}
default:
assert(0);
}
pTriggerStep = pTriggerStep->pNext;
}
sqlite3VdbeAddOp(v, OP_ContextPop, 0, 0);
VdbeComment((v, "# end trigger %s", pStepList->pTrig->name));
return 0;
}
/*
** 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 */
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 trigger will be created in */
iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
if( iDb<0 ){
goto trigger_cleanup;
}
}
if( !pTableName || db->mallocFailed ){
goto trigger_cleanup;
}
/* A long-standing parser bug is that this syntax was allowed:
**
** CREATE TRIGGER attached.demo AFTER INSERT ON attached.tab ....
** ^^^^^^^^
**
** To maintain backwards compatibility, ignore the database
** name on pTableName if we are reparsing out of SQLITE_MASTER.
*/
if( db->init.busy && iDb!=1 ){
sqlite3DbFree(db, pTableName->a[0].zDatabase);
pTableName->a[0].zDatabase = 0;
}
/* 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.
*/
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 );
sqlite3FixInit(&sFix, pParse, iDb, "trigger", pName);
if( 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;
}
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
if( sqlite3HashFind(&(db->aDb[iDb].pSchema->trigHash),zName) ){
if( !noErr ){
sqlite3ErrorMsg(pParse, "trigger %T already exists", pName);
}else{
assert( !db->init.busy );
sqlite3CodeVerifySchema(pParse, iDb);
}
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");
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 iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);
int code = SQLITE_CREATE_TRIGGER;
const char *zDb = db->aDb[iTabDb].zDbSName;
const char *zDbTrig = isTemp ? db->aDb[1].zDbSName : 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 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 */
int noErr /* Suppress errors if the trigger already exists */
){
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;
assert( pName1!=0 ); /* pName1->z might be NULL, but not pName1 itself */
assert( pName2!=0 );
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 || sqlite3MallocFailed() ){
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( sqlite3MallocFailed() ) 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;
}
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(pName);
if( !zName || SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
goto trigger_cleanup;
}
if( sqlite3HashFind(&(db->aDb[iDb].pSchema->trigHash), zName,strlen(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*)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 );
}
}
/*
** Generate VDBE code for the statements inside the body of a single
** trigger.
*/
static int codeTriggerProgram(
Parse *pParse, /* The parser context */
TriggerStep *pStepList, /* List of statements inside the trigger body */
int orconf /* Conflict algorithm. (OE_Abort, etc) */
){
TriggerStep *pStep;
Vdbe *v = pParse->pVdbe;
sqlite3 *db = pParse->db;
assert( pParse->pTriggerTab && pParse->pToplevel );
assert( pStepList );
assert( v!=0 );
for(pStep=pStepList; pStep; pStep=pStep->pNext){
/* Figure out the ON CONFLICT policy that will be used for this step
** of the trigger program. If the statement that caused this trigger
** to fire had an explicit ON CONFLICT, then use it. Otherwise, use
** the ON CONFLICT policy that was specified as part of the trigger
** step statement. Example:
**
** CREATE TRIGGER AFTER INSERT ON t1 BEGIN;
** INSERT OR REPLACE INTO t2 VALUES(new.a, new.b);
** END;
**
** INSERT INTO t1 ... ; -- insert into t2 uses REPLACE policy
** INSERT OR IGNORE INTO t1 ... ; -- insert into t2 uses IGNORE policy
*/
pParse->eOrconf = (orconf==OE_Default)?pStep->orconf:(u8)orconf;
/* Clear the cookieGoto flag. When coding triggers, the cookieGoto
** variable is used as a flag to indicate to sqlite3ExprCodeConstants()
** that it is not safe to refactor constants (this happens after the
** start of the first loop in the SQL statement is coded - at that
** point code may be conditionally executed, so it is no longer safe to
** initialize constant register values). */
assert( pParse->cookieGoto==0 || pParse->cookieGoto==-1 );
pParse->cookieGoto = 0;
switch( pStep->op ){
case TK_UPDATE: {
sqlite3Update(pParse,
targetSrcList(pParse, pStep),
sqlite3ExprListDup(db, pStep->pExprList, 0),
sqlite3ExprDup(db, pStep->pWhere, 0),
pParse->eOrconf
);
break;
}
case TK_INSERT: {
sqlite3Insert(pParse,
targetSrcList(pParse, pStep),
sqlite3ExprListDup(db, pStep->pExprList, 0),
sqlite3SelectDup(db, pStep->pSelect, 0),
sqlite3IdListDup(db, pStep->pIdList),
pParse->eOrconf
);
break;
}
case TK_DELETE: {
sqlite3DeleteFrom(pParse,
targetSrcList(pParse, pStep),
sqlite3ExprDup(db, pStep->pWhere, 0)
);
break;
}
default: assert( pStep->op==TK_SELECT ); {
SelectDest sDest;
Select *pSelect = sqlite3SelectDup(db, pStep->pSelect, 0);
sqlite3SelectDestInit(&sDest, SRT_Discard, 0);
sqlite3Select(pParse, pSelect, &sDest);
sqlite3SelectDelete(db, pSelect);
break;
}
}
if( pStep->op!=TK_SELECT ){
sqlite3VdbeAddOp0(v, OP_ResetCount);
}
}
return 0;
}