/*+
−
**+
−
** The author disclaims copyright to this source code.  In place of+
−
** a legal notice, here is a blessing:+
−
**+
−
**    May you do good and not evil.+
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**    May you find forgiveness for yourself and forgive others.+
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**    May you share freely, never taking more than you give.+
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**+
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*************************************************************************+
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*+
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*/+
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#include "sqliteInt.h"+
−
+
−
#ifndef SQLITE_OMIT_TRIGGER+
−
/*+
−
** Delete a linked list of TriggerStep structures.+
−
*/+
−
void sqlite3DeleteTriggerStep(TriggerStep *pTriggerStep){+
−
  while( pTriggerStep ){+
−
    TriggerStep * pTmp = pTriggerStep;+
−
    pTriggerStep = pTriggerStep->pNext;+
−
+
−
    if( pTmp->target.dyn ) sqlite3_free((char*)pTmp->target.z);+
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    sqlite3ExprDelete(pTmp->pWhere);+
−
    sqlite3ExprListDelete(pTmp->pExprList);+
−
    sqlite3SelectDelete(pTmp->pSelect);+
−
    sqlite3IdListDelete(pTmp->pIdList);+
−
+
−
    sqlite3_free(pTmp);+
−
  }+
−
}+
−
+
−
/*+
−
** This is called by the parser when it sees a CREATE TRIGGER statement+
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** up to the point of the BEGIN before the trigger actions.  A Trigger+
−
** structure is generated based on the information available and stored+
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** in pParse->pNewTrigger.  After the trigger actions have been parsed, the+
−
** sqlite3FinishTrigger() function is called to complete the trigger+
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** 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;+
−
  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 || db->mallocFailed ){+
−
    goto trigger_cleanup;+
−
  }+
−
  pTab = sqlite3SrcListLookup(pParse, pTableName);+
−
  if( pName2->n==0 && pTab && pTab->pSchema==db->aDb[1].pSchema ){+
−
    iDb = 1;+
−
  }+
−
+
−
  /* Ensure the table name matches database name and that the table exists */+
−
  if( db->mallocFailed ) goto trigger_cleanup;+
−
  assert( pTableName->nSrc==1 );+
−
  if( sqlite3FixInit(&sFix, pParse, iDb, "trigger", pName) && +
−
      sqlite3FixSrcList(&sFix, pTableName) ){+
−
    goto trigger_cleanup;+
−
  }+
−
  pTab = sqlite3SrcListLookup(pParse, pTableName);+
−
  if( !pTab ){+
−
    /* The table does not exist. */+
−
    goto trigger_cleanup;+
−
  }+
−
  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;+
−
  }+
−
  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*)sqlite3DbMallocZero(db, sizeof(Trigger));+
−
  if( pTrigger==0 ) goto trigger_cleanup;+
−
  pTrigger->name = zName;+
−
  zName = 0;+
−
  pTrigger->table = sqlite3DbStrDup(db, 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(db, pWhen);+
−
  pTrigger->pColumns = sqlite3IdListDup(db, pColumns);+
−
  sqlite3TokenCopy(db, &pTrigger->nameToken,pName);+
−
  assert( pParse->pNewTrigger==0 );+
−
  pParse->pNewTrigger = pTrigger;+
−
+
−
trigger_cleanup:+
−
  sqlite3_free(zName);+
−
  sqlite3SrcListDelete(pTableName);+
−
  sqlite3IdListDelete(pColumns);+
−
  sqlite3ExprDelete(pWhen);+
−
  if( !pParse->pNewTrigger ){+
−
    sqlite3DeleteTrigger(pTrigger);+
−
  }else{+
−
    assert( pParse->pNewTrigger==pTrigger );+
−
  }+
−
}+
−
+
−
/*+
−
** This routine is called after all of the trigger actions have been parsed+
−
** in order to complete the process of building the trigger.+
−
*/+
−
void sqlite3FinishTrigger(+
−
  Parse *pParse,          /* Parser context */+
−
  TriggerStep *pStepList, /* The triggered program */+
−
  Token *pAll             /* Token that describes the complete CREATE TRIGGER */+
−
){+
−
  Trigger *pTrig = 0;     /* The trigger whose construction is finishing up */+
−
  sqlite3 *db = pParse->db;  /* The database */+
−
  DbFixer sFix;+
−
  int iDb;                   /* Database containing the trigger */+
−
+
−
  pTrig = pParse->pNewTrigger;+
−
  pParse->pNewTrigger = 0;+
−
  if( pParse->nErr || !pTrig ) goto triggerfinish_cleanup;+
−
  iDb = sqlite3SchemaToIndex(pParse->db, pTrig->pSchema);+
−
  pTrig->step_list = pStepList;+
−
  while( pStepList ){+
−
    pStepList->pTrig = pTrig;+
−
    pStepList = pStepList->pNext;+
−
  }+
−
  if( sqlite3FixInit(&sFix, pParse, iDb, "trigger", &pTrig->nameToken) +
−
          && sqlite3FixTriggerStep(&sFix, pTrig->step_list) ){+
−
    goto triggerfinish_cleanup;+
−
  }+
−
+
−
  /* if we are not initializing, and this trigger is not on a TEMP table, +
−
  ** build the sqlite_master entry+
−
  */+
−
  if( !db->init.busy ){+
−
    static const VdbeOpList insertTrig[] = {+
−
      { OP_NewRowid,   0, 0,  0          },+
−
      { OP_String8,    0, 0,  "trigger"  },+
−
      { OP_String8,    0, 0,  0          },  /* 2: trigger name */+
−
      { OP_String8,    0, 0,  0          },  /* 3: table name */+
−
      { OP_Integer,    0, 0,  0          },+
−
      { OP_String8,    0, 0,  "CREATE TRIGGER "},+
−
      { OP_String8,    0, 0,  0          },  /* 6: SQL */+
−
      { OP_Concat,     0, 0,  0          }, +
−
      { OP_MakeRecord, 5, 0,  "aaada"    },+
−
      { OP_Insert,     0, 0,  0          },+
−
    };+
−
    int addr;+
−
    Vdbe *v;+
−
+
−
    /* Make an entry in the sqlite_master table */+
−
    v = sqlite3GetVdbe(pParse);+
−
    if( v==0 ) goto triggerfinish_cleanup;+
−
    sqlite3BeginWriteOperation(pParse, 0, iDb);+
−
    sqlite3OpenMasterTable(pParse, iDb);+
−
    addr = sqlite3VdbeAddOpList(v, ArraySize(insertTrig), insertTrig);+
−
    sqlite3VdbeChangeP3(v, addr+2, pTrig->name, 0); +
−
    sqlite3VdbeChangeP3(v, addr+3, pTrig->table, 0); +
−
    sqlite3VdbeChangeP3(v, addr+6, (char*)pAll->z, pAll->n);+
−
    sqlite3ChangeCookie(db, v, iDb);+
−
    sqlite3VdbeAddOp(v, OP_Close, 0, 0);+
−
    sqlite3VdbeOp3(v, OP_ParseSchema, iDb, 0, sqlite3MPrintf(+
−
        db, "type='trigger' AND name='%q'", pTrig->name), P3_DYNAMIC+
−
    );+
−
  }+
−
+
−
  if( db->init.busy ){+
−
    int n;+
−
    Table *pTab;+
−
    Trigger *pDel;+
−
    pDel = (Trigger*)sqlite3HashInsert(&db->aDb[iDb].pSchema->trigHash, +
−
                     pTrig->name, strlen(pTrig->name), pTrig);+
−
    if( pDel ){+
−
      assert( pDel==pTrig );+
−
      db->mallocFailed = 1;+
−
      goto triggerfinish_cleanup;+
−
    }+
−
    n = strlen(pTrig->table) + 1;+
−
    pTab = (Table*)sqlite3HashFind(&pTrig->pTabSchema->tblHash, pTrig->table, n);+
−
    assert( pTab!=0 );+
−
    pTrig->pNext = pTab->pTrigger;+
−
    pTab->pTrigger = pTrig;+
−
    pTrig = 0;+
−
  }+
−
+
−
triggerfinish_cleanup:+
−
  sqlite3DeleteTrigger(pTrig);+
−
  assert( !pParse->pNewTrigger );+
−
  sqlite3DeleteTriggerStep(pStepList);+
−
}+
−
+
−
/*+
−
** 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 sqlite3_malloc().  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 sqlite3_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 sqlite3_exec() call returns.+
−
*/+
−
static void sqlitePersistTriggerStep(sqlite3 *db, TriggerStep *p){+
−
  if( p->target.z ){+
−
    p->target.z = (u8*)sqlite3DbStrNDup(db, (char*)p->target.z, p->target.n);+
−
    p->target.dyn = 1;+
−
  }+
−
  if( p->pSelect ){+
−
    Select *pNew = sqlite3SelectDup(db, p->pSelect);+
−
    sqlite3SelectDelete(p->pSelect);+
−
    p->pSelect = pNew;+
−
  }+
−
  if( p->pWhere ){+
−
    Expr *pNew = sqlite3ExprDup(db, p->pWhere);+
−
    sqlite3ExprDelete(p->pWhere);+
−
    p->pWhere = pNew;+
−
  }+
−
  if( p->pExprList ){+
−
    ExprList *pNew = sqlite3ExprListDup(db, p->pExprList);+
−
    sqlite3ExprListDelete(p->pExprList);+
−
    p->pExprList = pNew;+
−
  }+
−
  if( p->pIdList ){+
−
    IdList *pNew = sqlite3IdListDup(db, p->pIdList);+
−
    sqlite3IdListDelete(p->pIdList);+
−
    p->pIdList = pNew;+
−
  }+
−
}+
−
+
−
/*+
−
** Turn a SELECT statement (that the pSelect parameter points to) into+
−
** a trigger step.  Return a pointer to a TriggerStep structure.+
−
**+
−
** The parser calls this routine when it finds a SELECT statement in+
−
** body of a TRIGGER.  +
−
*/+
−
TriggerStep *sqlite3TriggerSelectStep(sqlite3 *db, Select *pSelect){+
−
  TriggerStep *pTriggerStep = (TriggerStep*)sqlite3DbMallocZero(db, sizeof(TriggerStep));+
−
  if( pTriggerStep==0 ) {+
−
    sqlite3SelectDelete(pSelect);+
−
    return 0;+
−
  }+
−
+
−
  pTriggerStep->op = TK_SELECT;+
−
  pTriggerStep->pSelect = pSelect;+
−
  pTriggerStep->orconf = OE_Default;+
−
  sqlitePersistTriggerStep(db, pTriggerStep);+
−
+
−
  return pTriggerStep;+
−
}+
−
+
−
/*+
−
** Build a trigger step out of an INSERT statement.  Return a pointer+
−
** to the new trigger step.+
−
**+
−
** The parser calls this routine when it sees an INSERT inside the+
−
** body of a trigger.+
−
*/+
−
TriggerStep *sqlite3TriggerInsertStep(+
−
  sqlite3 *db,        /* The database connection */+
−
  Token *pTableName,  /* Name of the table into which we insert */+
−
  IdList *pColumn,    /* List of columns in pTableName to insert into */+
−
  ExprList *pEList,   /* The VALUE clause: a list of values to be inserted */+
−
  Select *pSelect,    /* A SELECT statement that supplies values */+
−
  int orconf          /* The conflict algorithm (OE_Abort, OE_Replace, etc.) */+
−
){+
−
  TriggerStep *pTriggerStep;+
−
+
−
  assert(pEList == 0 || pSelect == 0);+
−
  assert(pEList != 0 || pSelect != 0 || db->mallocFailed);+
−
+
−
  pTriggerStep = (TriggerStep*)sqlite3DbMallocZero(db, sizeof(TriggerStep));+
−
  if( pTriggerStep ){+
−
    pTriggerStep->op = TK_INSERT;+
−
    pTriggerStep->pSelect = pSelect;+
−
    pTriggerStep->target  = *pTableName;+
−
    pTriggerStep->pIdList = pColumn;+
−
    pTriggerStep->pExprList = pEList;+
−
    pTriggerStep->orconf = orconf;+
−
    sqlitePersistTriggerStep(db, pTriggerStep);+
−
  }else{+
−
    sqlite3IdListDelete(pColumn);+
−
    sqlite3ExprListDelete(pEList);+
−
    sqlite3SelectDelete(pSelect);+
−
  }+
−
+
−
  return pTriggerStep;+
−
}+
−
+
−
/*+
−
** Construct a trigger step that implements an UPDATE statement and return+
−
** a pointer to that trigger step.  The parser calls this routine when it+
−
** sees an UPDATE statement inside the body of a CREATE TRIGGER.+
−
*/+
−
TriggerStep *sqlite3TriggerUpdateStep(+
−
  sqlite3 *db,         /* The database connection */+
−
  Token *pTableName,   /* Name of the table to be updated */+
−
  ExprList *pEList,    /* The SET clause: list of column and new values */+
−
  Expr *pWhere,        /* The WHERE clause */+
−
  int orconf           /* The conflict algorithm. (OE_Abort, OE_Ignore, etc) */+
−
){+
−
  TriggerStep *pTriggerStep = (TriggerStep*)sqlite3DbMallocZero(db, sizeof(TriggerStep));+
−
  if( pTriggerStep==0 ){+
−
     sqlite3ExprListDelete(pEList);+
−
     sqlite3ExprDelete(pWhere);+
−
     return 0;+
−
  }+
−
+
−
  pTriggerStep->op = TK_UPDATE;+
−
  pTriggerStep->target  = *pTableName;+
−
  pTriggerStep->pExprList = pEList;+
−
  pTriggerStep->pWhere = pWhere;+
−
  pTriggerStep->orconf = orconf;+
−
  sqlitePersistTriggerStep(db, pTriggerStep);+
−
+
−
  return pTriggerStep;+
−
}+
−
+
−
/*+
−
** Construct a trigger step that implements a DELETE statement and return+
−
** a pointer to that trigger step.  The parser calls this routine when it+
−
** sees a DELETE statement inside the body of a CREATE TRIGGER.+
−
*/+
−
TriggerStep *sqlite3TriggerDeleteStep(+
−
  sqlite3 *db,            /* Database connection */+
−
  Token *pTableName,      /* The table from which rows are deleted */+
−
  Expr *pWhere            /* The WHERE clause */+
−
){+
−
  TriggerStep *pTriggerStep = (TriggerStep*)sqlite3DbMallocZero(db, sizeof(TriggerStep));+
−
  if( pTriggerStep==0 ){+
−
    sqlite3ExprDelete(pWhere);+
−
    return 0;+
−
  }+
−
+
−
  pTriggerStep->op = TK_DELETE;+
−
  pTriggerStep->target  = *pTableName;+
−
  pTriggerStep->pWhere = pWhere;+
−
  pTriggerStep->orconf = OE_Default;+
−
  sqlitePersistTriggerStep(db, pTriggerStep);+
−
+
−
  return pTriggerStep;+
−
}+
−
+
−
/* +
−
** Recursively delete a Trigger structure+
−
*/+
−
void sqlite3DeleteTrigger(Trigger *pTrigger){+
−
  if( pTrigger==0 ) return;+
−
  sqlite3DeleteTriggerStep(pTrigger->step_list);+
−
  sqlite3_free(pTrigger->name);+
−
  sqlite3_free(pTrigger->table);+
−
  sqlite3ExprDelete(pTrigger->pWhen);+
−
  sqlite3IdListDelete(pTrigger->pColumns);+
−
  if( pTrigger->nameToken.dyn ) sqlite3_free((char*)pTrigger->nameToken.z);+
−
  sqlite3_free(pTrigger);+
−
}+
−
+
−
/*+
−
** This function is called to drop a trigger from the database schema. +
−
**+
−
** This may be called directly from the parser and therefore identifies+
−
** the trigger by name.  The sqlite3DropTriggerPtr() routine does the+
−
** same job as this routine except it takes a pointer to the trigger+
−
** instead of the trigger name.+
−
**/+
−
void sqlite3DropTrigger(Parse *pParse, SrcList *pName, int noErr){+
−
  Trigger *pTrigger = 0;+
−
  int i;+
−
  const char *zDb;+
−
  const char *zName;+
−
  int nName;+
−
  sqlite3 *db = pParse->db;+
−
+
−
  if( db->mallocFailed ) goto drop_trigger_cleanup;+
−
  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){+
−
    goto drop_trigger_cleanup;+
−
  }+
−
+
−
  assert( pName->nSrc==1 );+
−
  zDb = pName->a[0].zDatabase;+
−
  zName = pName->a[0].zName;+
−
  nName = strlen(zName);+
−
  for(i=OMIT_TEMPDB; i<db->nDb; i++){+
−
    int j = (i<2) ? i^1 : i;  /* Search TEMP before MAIN */+
−
    if( zDb && sqlite3StrICmp(db->aDb[j].zName, zDb) ) continue;+
−
    pTrigger = (Trigger*)sqlite3HashFind(&(db->aDb[j].pSchema->trigHash), zName, nName);+
−
    if( pTrigger ) break;+
−
  }+
−
  if( !pTrigger ){+
−
    if( !noErr ){+
−
      sqlite3ErrorMsg(pParse, "no such trigger: %S", pName, 0);+
−
    }+
−
    goto drop_trigger_cleanup;+
−
  }+
−
  sqlite3DropTriggerPtr(pParse, pTrigger);+
−
+
−
drop_trigger_cleanup:+
−
  sqlite3SrcListDelete(pName);+
−
}+
−
+
−
/*+
−
** Return a pointer to the Table structure for the table that a trigger+
−
** is set on.+
−
*/+
−
static Table *tableOfTrigger(Trigger *pTrigger){+
−
  int n = strlen(pTrigger->table) + 1;+
−
  return (Table*)sqlite3HashFind(&pTrigger->pTabSchema->tblHash, pTrigger->table, n);+
−
}+
−
+
−
+
−
/*+
−
** Drop a trigger given a pointer to that trigger. +
−
*/+
−
void sqlite3DropTriggerPtr(Parse *pParse, Trigger *pTrigger){+
−
  Table   *pTable;+
−
  Vdbe *v;+
−
  sqlite3 *db = pParse->db;+
−
  int iDb;+
−
+
−
  iDb = sqlite3SchemaToIndex(pParse->db, pTrigger->pSchema);+
−
  assert( iDb>=0 && iDb<db->nDb );+
−
  pTable = tableOfTrigger(pTrigger);+
−
  assert( pTable );+
−
  assert( pTable->pSchema==pTrigger->pSchema || iDb==1 );+
−
#ifndef SQLITE_OMIT_AUTHORIZATION+
−
  {+
−
    int code = SQLITE_DROP_TRIGGER;+
−
    const char *zDb = db->aDb[iDb].zName;+
−
    const char *zTab = SCHEMA_TABLE(iDb);+
−
    if( iDb==1 ) code = SQLITE_DROP_TEMP_TRIGGER;+
−
    if( sqlite3AuthCheck(pParse, code, pTrigger->name, pTable->zName, zDb) ||+
−
      sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb) ){+
−
      return;+
−
    }+
−
  }+
−
#endif+
−
+
−
  /* Generate code to destroy the database record of the trigger.+
−
  */+
−
  assert( pTable!=0 );+
−
  if( (v = sqlite3GetVdbe(pParse))!=0 ){+
−
    int base;+
−
    static const VdbeOpList dropTrigger[] = {+
−
      { OP_Rewind,     0, ADDR(9),  0},+
−
      { OP_String8,    0, 0,        0}, /* 1 */+
−
      { OP_Column,     0, 1,        0},+
−
      { OP_Ne,         0, ADDR(8),  0},+
−
      { OP_String8,    0, 0,        "trigger"},+
−
      { OP_Column,     0, 0,        0},+
−
      { OP_Ne,         0, ADDR(8),  0},+
−
      { OP_Delete,     0, 0,        0},+
−
      { OP_Next,       0, ADDR(1),  0}, /* 8 */+
−
    };+
−
+
−
    sqlite3BeginWriteOperation(pParse, 0, iDb);+
−
    sqlite3OpenMasterTable(pParse, iDb);+
−
    base = sqlite3VdbeAddOpList(v,  ArraySize(dropTrigger), dropTrigger);+
−
    sqlite3VdbeChangeP3(v, base+1, pTrigger->name, 0);+
−
    sqlite3ChangeCookie(db, v, iDb);+
−
    sqlite3VdbeAddOp(v, OP_Close, 0, 0);+
−
    sqlite3VdbeOp3(v, OP_DropTrigger, iDb, 0, pTrigger->name, 0);+
−
  }+
−
}+
−
+
−
/*+
−
** Remove a trigger from the hash tables of the sqlite* pointer.+
−
*/+
−
void sqlite3UnlinkAndDeleteTrigger(sqlite3 *db, int iDb, const char *zName){+
−
  Trigger *pTrigger;+
−
  int nName = strlen(zName);+
−
  pTrigger = (Trigger*)sqlite3HashInsert(&(db->aDb[iDb].pSchema->trigHash),+
−
                               zName, nName, 0);+
−
  if( pTrigger ){+
−
    Table *pTable = tableOfTrigger(pTrigger);+
−
    assert( pTable!=0 );+
−
    if( pTable->pTrigger == pTrigger ){+
−
      pTable->pTrigger = pTrigger->pNext;+
−
    }else{+
−
      Trigger *cc = pTable->pTrigger;+
−
      while( cc ){ +
−
        if( cc->pNext == pTrigger ){+
−
          cc->pNext = cc->pNext->pNext;+
−
          break;+
−
        }+
−
        cc = cc->pNext;+
−
      }+
−
      assert(cc);+
−
    }+
−
    sqlite3DeleteTrigger(pTrigger);+
−
    db->flags |= SQLITE_InternChanges;+
−
  }+
−
}+
−
+
−
/*+
−
** pEList is the SET clause of an UPDATE statement.  Each entry+
−
** in pEList is of the format <id>=<expr>.  If any of the entries+
−
** in pEList have an <id> which matches an identifier in pIdList,+
−
** then return TRUE.  If pIdList==NULL, then it is considered a+
−
** wildcard that matches anything.  Likewise if pEList==NULL then+
−
** it matches anything so always return true.  Return false only+
−
** if there is no match.+
−
*/+
−
static int checkColumnOverLap(IdList *pIdList, ExprList *pEList){+
−
  int e;+
−
  if( !pIdList || !pEList ) return 1;+
−
  for(e=0; e<pEList->nExpr; e++){+
−
    if( sqlite3IdListIndex(pIdList, pEList->a[e].zName)>=0 ) return 1;+
−
  }+
−
  return 0; +
−
}+
−
+
−
/*+
−
** Return a bit vector to indicate what kind of triggers exist for operation+
−
** "op" on table pTab.  If pChanges is not NULL then it is a list of columns+
−
** that are being updated.  Triggers only match if the ON clause of the+
−
** trigger definition overlaps the set of columns being updated.+
−
**+
−
** The returned bit vector is some combination of TRIGGER_BEFORE and+
−
** TRIGGER_AFTER.+
−
*/+
−
int sqlite3TriggersExist(+
−
  Parse *pParse,          /* Used to check for recursive triggers */+
−
  Table *pTab,            /* The table the contains the triggers */+
−
  int op,                 /* one of TK_DELETE, TK_INSERT, TK_UPDATE */+
−
  ExprList *pChanges      /* Columns that change in an UPDATE statement */+
−
){+
−
  Trigger *pTrigger;+
−
  int mask = 0;+
−
+
−
  pTrigger = IsVirtual(pTab) ? 0 : pTab->pTrigger;+
−
  while( pTrigger ){+
−
    if( pTrigger->op==op && checkColumnOverLap(pTrigger->pColumns, pChanges) ){+
−
      mask |= pTrigger->tr_tm;+
−
    }+
−
    pTrigger = pTrigger->pNext;+
−
  }+
−
  return mask;+
−
}+
−
+
−
/*+
−
** Convert the pStep->target token into a SrcList and return a pointer+
−
** to that SrcList.+
−
**+
−
** This routine adds a specific database name, if needed, to the target when+
−
** forming the SrcList.  This prevents a trigger in one database from+
−
** referring to a target in another database.  An exception is when the+
−
** trigger is in TEMP in which case it can refer to any other database it+
−
** wants.+
−
*/+
−
static SrcList *targetSrcList(+
−
  Parse *pParse,       /* The parsing context */+
−
  TriggerStep *pStep   /* The trigger containing the target token */+
−
){+
−
  Token sDb;           /* Dummy database name token */+
−
  int iDb;             /* Index of the database to use */+
−
  SrcList *pSrc;       /* SrcList to be returned */+
−
+
−
  iDb = sqlite3SchemaToIndex(pParse->db, pStep->pTrig->pSchema);+
−
  if( iDb==0 || iDb>=2 ){+
−
    assert( iDb<pParse->db->nDb );+
−
    sDb.z = (u8*)pParse->db->aDb[iDb].zName;+
−
    sDb.n = strlen((char*)sDb.z);+
−
    pSrc = sqlite3SrcListAppend(pParse->db, 0, &sDb, &pStep->target);+
−
  } else {+
−
    pSrc = sqlite3SrcListAppend(pParse->db, 0, &pStep->target, 0);+
−
  }+
−
  return pSrc;+
−
}+
−
+
−
/*+
−
** 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;+
−
  sqlite3 *db = pParse->db;+
−
+
−
  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(db, 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(db, pTriggerStep->pExprList), +
−
                sqlite3ExprDup(db, 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(db, pTriggerStep->pExprList), +
−
          sqlite3SelectDup(db, pTriggerStep->pSelect), +
−
          sqlite3IdListDup(db, 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(db, 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 to code FOR EACH ROW triggers.+
−
**+
−
** When the code that this function generates is executed, the following +
−
** must be true:+
−
**+
−
** 1. No cursors may be open in the main database.  (But newIdx and oldIdx+
−
**    can be indices of cursors in temporary tables.  See below.)+
−
**+
−
** 2. If the triggers being coded are ON INSERT or ON UPDATE triggers, then+
−
**    a temporary vdbe cursor (index newIdx) must be open and pointing at+
−
**    a row containing values to be substituted for new.* expressions in the+
−
**    trigger program(s).+
−
**+
−
** 3. If the triggers being coded are ON DELETE or ON UPDATE triggers, then+
−
**    a temporary vdbe cursor (index oldIdx) must be open and pointing at+
−
**    a row containing values to be substituted for old.* expressions in the+
−
**    trigger program(s).+
−
**+
−
*/+
−
int sqlite3CodeRowTrigger(+
−
  Parse *pParse,       /* Parse context */+
−
  int op,              /* One of TK_UPDATE, TK_INSERT, TK_DELETE */+
−
  ExprList *pChanges,  /* Changes list for any UPDATE OF triggers */+
−
  int tr_tm,           /* One of TRIGGER_BEFORE, TRIGGER_AFTER */+
−
  Table *pTab,         /* The table to code triggers from */+
−
  int newIdx,          /* The indice of the "new" row to access */+
−
  int oldIdx,          /* The indice of the "old" row to access */+
−
  int orconf,          /* ON CONFLICT policy */+
−
  int ignoreJump       /* Instruction to jump to for RAISE(IGNORE) */+
−
){+
−
  Trigger *p;+
−
  TriggerStack trigStackEntry;+
−
+
−
  assert(op == TK_UPDATE || op == TK_INSERT || op == TK_DELETE);+
−
  assert(tr_tm == TRIGGER_BEFORE || tr_tm == TRIGGER_AFTER );+
−
+
−
  assert(newIdx != -1 || oldIdx != -1);+
−
+
−
  for(p=pTab->pTrigger; p; p=p->pNext){+
−
    int fire_this = 0;+
−
    sqlite3 *db = pParse->db;+
−
+
−
    /* Determine whether we should code this trigger */+
−
    if( +
−
      p->op==op && +
−
      p->tr_tm==tr_tm && +
−
      (p->pSchema==p->pTabSchema || p->pSchema==db->aDb[1].pSchema) &&+
−
      (op!=TK_UPDATE||!p->pColumns||checkColumnOverLap(p->pColumns,pChanges))+
−
    ){+
−
      TriggerStack *pS;      /* Pointer to trigger-stack entry */+
−
      for(pS=pParse->trigStack; pS && p!=pS->pTrigger; pS=pS->pNext){}+
−
      if( !pS ){+
−
        fire_this = 1;+
−
      }+
−
#if 0    /* Give no warning for recursive triggers.  Just do not do them */+
−
      else{+
−
        sqlite3ErrorMsg(pParse, "recursive triggers not supported (%s)",+
−
            p->name);+
−
        return SQLITE_ERROR;+
−
      }+
−
#endif+
−
    }+
−
 +
−
    if( fire_this ){+
−
      int endTrigger;+
−
      Expr * whenExpr;+
−
      AuthContext sContext;+
−
      NameContext sNC;+
−
+
−
      memset(&sNC, 0, sizeof(sNC));+
−
      sNC.pParse = pParse;+
−
+
−
      /* Push an entry on to the trigger stack */+
−
      trigStackEntry.pTrigger = p;+
−
      trigStackEntry.newIdx = newIdx;+
−
      trigStackEntry.oldIdx = oldIdx;+
−
      trigStackEntry.pTab = pTab;+
−
      trigStackEntry.pNext = pParse->trigStack;+
−
      trigStackEntry.ignoreJump = ignoreJump;+
−
      pParse->trigStack = &trigStackEntry;+
−
      sqlite3AuthContextPush(pParse, &sContext, p->name);+
−
+
−
      /* code the WHEN clause */+
−
      endTrigger = sqlite3VdbeMakeLabel(pParse->pVdbe);+
−
      whenExpr = sqlite3ExprDup(db, p->pWhen);+
−
      if( db->mallocFailed || sqlite3ExprResolveNames(&sNC, whenExpr) ){+
−
        pParse->trigStack = trigStackEntry.pNext;+
−
        sqlite3ExprDelete(whenExpr);+
−
        return 1;+
−
      }+
−
      sqlite3ExprIfFalse(pParse, whenExpr, endTrigger, 1);+
−
      sqlite3ExprDelete(whenExpr);+
−
+
−
      codeTriggerProgram(pParse, p->step_list, orconf); +
−
+
−
      /* Pop the entry off the trigger stack */+
−
      pParse->trigStack = trigStackEntry.pNext;+
−
      sqlite3AuthContextPop(&sContext);+
−
+
−
      sqlite3VdbeResolveLabel(pParse->pVdbe, endTrigger);+
−
    }+
−
  }+
−
  return 0;+
−
}+
−
#endif /* !defined(SQLITE_OMIT_TRIGGER) */+
−