/*
** Make a copy of all components of the given trigger step. This has
** the effect of copying all Expr.token.z values into memory obtained
** from sqliteMalloc(). As initially created, the Expr.token.z values
** all point to the input string that was fed to the parser. But that
** string is ephemeral - it will go away as soon as the sqlite_exec()
** call that started the parser exits. This routine makes a persistent
** copy of all the Expr.token.z strings so that the TriggerStep structure
** will be valid even after the sqlite_exec() call returns.
*/
static void sqlitePersistTriggerStep(TriggerStep *p){
if( p->target.z ){
p->target.z = sqliteStrNDup(p->target.z, p->target.n);
p->target.dyn = 1;
}
if( p->pSelect ){
Select *pNew = sqliteSelectDup(p->pSelect);
sqliteSelectDelete(p->pSelect);
p->pSelect = pNew;
}
if( p->pWhere ){
Expr *pNew = sqliteExprDup(p->pWhere);
sqliteExprDelete(p->pWhere);
p->pWhere = pNew;
}
if( p->pExprList ){
ExprList *pNew = sqliteExprListDup(p->pExprList);
sqliteExprListDelete(p->pExprList);
p->pExprList = pNew;
}
if( p->pIdList ){
IdList *pNew = sqliteIdListDup(p->pIdList);
sqliteIdListDelete(p->pIdList);
p->pIdList = pNew;
}
}
/*
** 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;
while( pTriggerStep ){
int saveNTab = pParse->nTab;
orconf = (orconfin == OE_Default)?pTriggerStep->orconf:orconfin;
pParse->trigStack->orconf = orconf;
switch( pTriggerStep->op ){
case TK_SELECT: {
Select * ss = sqliteSelectDup(pTriggerStep->pSelect);
assert(ss);
assert(ss->pSrc);
sqliteSelect(pParse, ss, SRT_Discard, 0, 0, 0, 0);
sqliteSelectDelete(ss);
break;
}
case TK_UPDATE: {
SrcList *pSrc;
pSrc = targetSrcList(pParse, pTriggerStep);
sqliteVdbeAddOp(pParse->pVdbe, OP_ListPush, 0, 0);
sqliteUpdate(pParse, pSrc,
sqliteExprListDup(pTriggerStep->pExprList),
sqliteExprDup(pTriggerStep->pWhere), orconf);
sqliteVdbeAddOp(pParse->pVdbe, OP_ListPop, 0, 0);
break;
}
case TK_INSERT: {
SrcList *pSrc;
pSrc = targetSrcList(pParse, pTriggerStep);
sqliteInsert(pParse, pSrc,
sqliteExprListDup(pTriggerStep->pExprList),
sqliteSelectDup(pTriggerStep->pSelect),
sqliteIdListDup(pTriggerStep->pIdList), orconf);
break;
}
case TK_DELETE: {
SrcList *pSrc;
sqliteVdbeAddOp(pParse->pVdbe, OP_ListPush, 0, 0);
pSrc = targetSrcList(pParse, pTriggerStep);
sqliteDeleteFrom(pParse, pSrc, sqliteExprDup(pTriggerStep->pWhere));
sqliteVdbeAddOp(pParse->pVdbe, OP_ListPop, 0, 0);
break;
}
default:
assert(0);
}
pParse->nTab = saveNTab;
pTriggerStep = pTriggerStep->pNext;
}
return 0;
}
SrcList *sqliteSrcListDup(SrcList *p){
SrcList *pNew;
int i;
int nByte;
if( p==0 ) return 0;
nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
pNew = sqliteMallocRaw( nByte );
if( pNew==0 ) return 0;
pNew->nSrc = pNew->nAlloc = p->nSrc;
for(i=0; i<p->nSrc; i++){
struct SrcList_item *pNewItem = &pNew->a[i];
struct SrcList_item *pOldItem = &p->a[i];
pNewItem->zDatabase = sqliteStrDup(pOldItem->zDatabase);
pNewItem->zName = sqliteStrDup(pOldItem->zName);
pNewItem->zAlias = sqliteStrDup(pOldItem->zAlias);
pNewItem->jointype = pOldItem->jointype;
pNewItem->iCursor = pOldItem->iCursor;
pNewItem->pTab = 0;
pNewItem->pSelect = sqliteSelectDup(pOldItem->pSelect);
pNewItem->pOn = sqliteExprDup(pOldItem->pOn);
pNewItem->pUsing = sqliteIdListDup(pOldItem->pUsing);
}
return pNew;
}
/*
** 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
** sqliteFinishTrigger() function is called to complete the trigger
** construction process.
*/
void sqliteBeginTrigger(
Parse *pParse, /* The parse context of the CREATE TRIGGER statement */
Token *pName, /* 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 *nt;
Table *tab;
char *zName = 0; /* Name of the trigger */
sqlite *db = pParse->db;
int iDb; /* When database to store the trigger in */
DbFixer sFix;
/* Check that:
** 1. the trigger name does not already exist.
** 2. the table (or view) does exist in the same database as the trigger.
** 3. that we are not trying to create a trigger on the sqlite_master table
** 4. That we are not trying to create an INSTEAD OF trigger on a table.
** 5. That we are not trying to create a BEFORE or AFTER trigger on a view.
*/
if( sqlite_malloc_failed ) goto trigger_cleanup;
assert( pTableName->nSrc==1 );
if( db->init.busy
&& sqliteFixInit(&sFix, pParse, db->init.iDb, "trigger", pName)
&& sqliteFixSrcList(&sFix, pTableName)
){
goto trigger_cleanup;
}
tab = sqliteSrcListLookup(pParse, pTableName);
if( !tab ){
goto trigger_cleanup;
}
iDb = isTemp ? 1 : tab->iDb;
if( iDb>=2 && !db->init.busy ){
sqliteErrorMsg(pParse, "triggers may not be added to auxiliary "
"database %s", db->aDb[tab->iDb].zName);
goto trigger_cleanup;
}
zName = sqliteStrNDup(pName->z, pName->n);
sqliteDequote(zName);
if( sqliteHashFind(&(db->aDb[iDb].trigHash), zName,pName->n+1) ){
sqliteErrorMsg(pParse, "trigger %T already exists", pName);
goto trigger_cleanup;
}
if( sqliteStrNICmp(tab->zName, "sqlite_", 7)==0 ){
sqliteErrorMsg(pParse, "cannot create trigger on system table");
pParse->nErr++;
goto trigger_cleanup;
}
if( tab->pSelect && tr_tm != TK_INSTEAD ){
sqliteErrorMsg(pParse, "cannot create %s trigger on view: %S",
(tr_tm == TK_BEFORE)?"BEFORE":"AFTER", pTableName, 0);
goto trigger_cleanup;
}
if( !tab->pSelect && tr_tm == TK_INSTEAD ){
sqliteErrorMsg(pParse, "cannot create INSTEAD OF"
" trigger on table: %S", pTableName, 0);
goto trigger_cleanup;
}
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int code = SQLITE_CREATE_TRIGGER;
const char *zDb = db->aDb[tab->iDb].zName;
const char *zDbTrig = isTemp ? db->aDb[1].zName : zDb;
if( tab->iDb==1 || isTemp ) code = SQLITE_CREATE_TEMP_TRIGGER;
if( sqliteAuthCheck(pParse, code, zName, tab->zName, zDbTrig) ){
goto trigger_cleanup;
}
if( sqliteAuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(tab->iDb), 0, zDb)){
goto trigger_cleanup;
}
}
#endif
/* INSTEAD OF triggers can only appear on views and BEGIN 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 */
nt = (Trigger*)sqliteMalloc(sizeof(Trigger));
if( nt==0 ) goto trigger_cleanup;
nt->name = zName;
zName = 0;
nt->table = sqliteStrDup(pTableName->a[0].zName);
if( sqlite_malloc_failed ) goto trigger_cleanup;
nt->iDb = iDb;
nt->iTabDb = tab->iDb;
nt->op = op;
nt->tr_tm = tr_tm;
nt->pWhen = sqliteExprDup(pWhen);
nt->pColumns = sqliteIdListDup(pColumns);
nt->foreach = foreach;
sqliteTokenCopy(&nt->nameToken,pName);
assert( pParse->pNewTrigger==0 );
pParse->pNewTrigger = nt;
trigger_cleanup:
sqliteFree(zName);
sqliteSrcListDelete(pTableName);
sqliteIdListDelete(pColumns);
sqliteExprDelete(pWhen);
}
