SQLite

** The code generated by this function scans through the rows in the child
** table that correspond to the parent table row being deleted or inserted.
** For each child row found, one of the following actions is taken:
**
**   Operation | FK type   | Action taken
**   --------------------------------------------------------------------------
**   DELETE      immediate   Increment the "immediate constraint counter".


**
**   INSERT      immediate   Decrement the "immediate constraint counter".
**
**   DELETE      deferred    Increment the "deferred constraint counter".


**
**   INSERT      deferred    Decrement the "deferred constraint counter".
**
** These operations are identified in the comment at the top of this file 
** (fkey.c) as "I.2" and "D.2".
*/
static void fkScanChildren(

** compiled on table pTab, which is the parent table of foreign-key pFKey.
** If the current operation is an UPDATE, then the pChanges parameter is
** passed a pointer to the list of columns being modified. If it is a
** DELETE, pChanges is passed a NULL pointer.
**
** It returns a pointer to a Trigger structure containing a trigger
** equivalent to the ON UPDATE or ON DELETE action specified by pFKey.
** If the action is "NO ACTION" then a NULL pointer is returned (these actions
** require no special handling by the triggers sub-system, code for them is
** created by fkScanChildren()).
**
** For example, if pFKey is the foreign key and pTab is table "p" in 
** the following schema:
**
**   CREATE TABLE p(pk PRIMARY KEY);
**   CREATE TABLE c(ck REFERENCES p ON DELETE CASCADE);
**

    }
    sqlite3DbFree(db, aiCol);

    zFrom = pFKey->pFrom->zName;
    nFrom = sqlite3Strlen30(zFrom);

    if( action==OE_Restrict ){
      int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
      Token tFrom;
      Token tDb;
      Expr *pRaise; 

      tFrom.z = zFrom;
      tFrom.n = nFrom;
      tDb.z = db->aDb[iDb].zDbSName;
      tDb.n = sqlite3Strlen30(tDb.z);

      pRaise = sqlite3Expr(db, TK_RAISE, "FOREIGN KEY constraint failed");
      if( pRaise ){
        pRaise->affExpr = OE_Abort;
      }
      pSelect = sqlite3SelectNew(pParse, 
          sqlite3ExprListAppend(pParse, 0, pRaise),
          sqlite3SrcListAppend(pParse, 0, &tDb, &tFrom),
          pWhere,
          0, 0, 0, 0, 0
      );
      pWhere = 0;
    }

    /* Disable lookaside memory allocation */

    INSERT INTO child VALUES(456);
    UPDATE parent SET p = '456' WHERE p=1200;
  COMMIT;
}
do_execsql_test 5.3 {
  PRAGMA integrity_check;
} {ok}

#-------------------------------------------------------------------------
reset_db
forcedelete test.db2
do_execsql_test 6.1 {
  PRAGMA foreign_keys = on;
  CREATE TABLE c1(b);
  INSERT INTO c1 VALUES(123);
}

do_execsql_test 6.2 {
  ATTACH 'test.db2' AS aux;
  CREATE TABLE aux.p1(a INTEGER PRIMARY KEY);
  CREATE TABLE aux.c1(b REFERENCES p1(a) ON DELETE RESTRICT);

  INSERT INTO aux.p1 VALUES(123);
}

do_execsql_test 6.3 {
  DELETE FROM aux.p1 WHERE a=123;
}


finish_test