示例#1
0
/*
** 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;
}
示例#2
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;
}
示例#3
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 );
  }
}
示例#4
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 */
  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;
}