SQLite

}
do_conflict_test 3.2.3 -tables t2 -sql {
  DELETE FROM t2 WHERE a = 1;
  DELETE FROM t2 WHERE a = 2;
  DELETE FROM t2 WHERE a = 3;
  DELETE FROM t2 WHERE a = 4;
} -conflicts {

  {DELETE t2 NOTFOUND {i 3 t three}}
  {DELETE t2 DATA {i 4 t four} {i 4 t five}}
  {FOREIGN_KEY 1}
}
do_execsql_test 3.2.4 "SELECT * FROM t2" {}
do_db2_test     3.2.5 "SELECT * FROM t2" {4 five}

# Test UPDATE changesets.
#
do_execsql_test 3.3.1 {
  CREATE TABLE t4(a, b, c, PRIMARY KEY(b, c));
  INSERT INTO t4 VALUES(1, 2, 3);
  INSERT INTO t4 VALUES(4, 5, 6);

# 2013 July 04
#
# 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.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
# This file tests that the sessions module handles foreign key constraint
# violations when applying changesets as required.
#

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source [file join [file dirname [info script]] session_common.tcl]
source $testdir/tester.tcl
ifcapable !session {finish_test; return}
set testprefix session9


#--------------------------------------------------------------------
#

proc populate_db {} {
  drop_all_tables
  execsql {
    PRAGMA foreign_keys = 1;
    CREATE TABLE p1(a PRIMARY KEY, b);
    CREATE TABLE c1(a PRIMARY KEY, b REFERENCES p1);
    CREATE TABLE c2(a PRIMARY KEY, 
        b REFERENCES p1 DEFERRABLE INITIALLY DEFERRED
    );

    INSERT INTO p1 VALUES(1, 'one');
    INSERT INTO p1 VALUES(2, 'two');
    INSERT INTO p1 VALUES(3, 'three');
    INSERT INTO p1 VALUES(4, 'four');
  }
}

proc capture_changeset {sql} {
  sqlite3session S db main

  foreach t [db eval {SELECT name FROM sqlite_master WHERE type='table'}] {
    S attach $t
  }
  execsql $sql
  set ret [S changeset]
  S delete

  return $ret
}

do_test 1.1 {
  populate_db
  set cc [capture_changeset {
    INSERT INTO c1 VALUES('ii', 2);
    INSERT INTO c2 VALUES('iii', 3);
  }]
  set {} {}
} {}

proc xConflict {args} {
  lappend ::xConflict {*}$args
  return $::conflictret
}

foreach {tn delrow trans conflictargs conflictret} {
  1   2 0 {FOREIGN_KEY 1} OMIT
  2   3 0 {FOREIGN_KEY 1} OMIT
  3   2 1 {FOREIGN_KEY 1} OMIT
  4   3 1 {FOREIGN_KEY 1} OMIT
  5   2 0 {FOREIGN_KEY 1} ABORT
  6   3 0 {FOREIGN_KEY 1} ABORT
  7   2 1 {FOREIGN_KEY 1} ABORT
  8   3 1 {FOREIGN_KEY 1} ABORT
} {

  set A(OMIT)  {0 {}}
  set A(ABORT) {1 SQLITE_CONSTRAINT}
  do_test 1.2.$tn.1 {
    populate_db
    execsql { DELETE FROM p1 WHERE a=($delrow+0) }
    if {$trans} { execsql BEGIN }

    set ::xConflict [list]
    list [catch {sqlite3changeset_apply db $::cc xConflict} msg] $msg
  } $A($conflictret)

  do_test 1.2.$tn.2 { set ::xConflict } $conflictargs

  set A(OMIT)  {1 1}
  set A(ABORT) {0 0}
  do_test 1.2.$tn.3 {
    execsql { SELECT count(*) FROM c1 UNION ALL SELECT count(*) FROM c2 }
  } $A($conflictret)

  do_test 1.2.$tn.4 { expr ![sqlite3_get_autocommit db] } $trans
  do_test 1.2.$tn.5 {
    if { $trans } { execsql COMMIT }
  } {}
}

#--------------------------------------------------------------------
# Test that closing a transaction clears the defer_foreign_keys flag.
#
foreach {tn open noclose close} {
  1 BEGIN {} COMMIT
  2 BEGIN {} ROLLBACK

  3 {SAVEPOINT one} {}                {RELEASE one}
  4 {SAVEPOINT one} {ROLLBACK TO one} {RELEASE one}
} {
  execsql $open
  do_execsql_test 2.$tn.1 { PRAGMA defer_foreign_keys } {0}

  do_execsql_test 2.$tn.2 {
    PRAGMA defer_foreign_keys = 1;
    PRAGMA defer_foreign_keys;
  } {1}

  execsql $noclose
  do_execsql_test 2.$tn.3 { PRAGMA defer_foreign_keys } {1}

  execsql $close
  do_execsql_test 2.$tn.4 { PRAGMA defer_foreign_keys } {0}
}

finish_test

#if defined(SQLITE_ENABLE_SESSION) && defined(SQLITE_ENABLE_PREUPDATE_HOOK)

#include "sqlite3session.h"
#include <assert.h>
#include <string.h>

#ifndef SQLITE_AMALGAMATION
# include "sqliteInt.h"
# include "vdbeInt.h"

  }
  if( iVal<0 || iVal>=sqlite3_column_count(pIter->pConflict) ){
    return SQLITE_RANGE;
  }
  *ppValue = sqlite3_column_value(pIter->pConflict, iVal);
  return SQLITE_OK;
}

/*
** This function may only be called with an iterator passed to an
** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
** it sets the output variable to the total number of known foreign key
** violations in the destination database and returns SQLITE_OK.
**
** In all other cases this function returns SQLITE_MISUSE.
*/
int sqlite3changeset_fk_conflicts(
  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
  int *pnOut                      /* OUT: Number of FK violations */
){
  if( pIter->pConflict || pIter->apValue ){
    return SQLITE_MISUSE;
  }
  *pnOut = pIter->nCol;
  return SQLITE_OK;
}


/*
** Finalize an iterator allocated with sqlite3changeset_start().
**
** This function may not be called on iterators passed to a conflict handler
** callback by changeset_apply().
*/

  memset(&sApply, 0, sizeof(sApply));
  rc = sqlite3changeset_start(&pIter, nChangeset, pChangeset);
  if( rc!=SQLITE_OK ) return rc;

  sqlite3_mutex_enter(sqlite3_db_mutex(db));
  rc = sqlite3_exec(db, "SAVEPOINT changeset_apply", 0, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_exec(db, "PRAGMA defer_foreign_keys = 1", 0, 0, 0);
  }
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3changeset_next(pIter) ){
    int nCol;
    int op;
    int bReplace = 0;
    int bRetry = 0;
    const char *zNew;
    

  if( rc==SQLITE_OK ){
    rc = sqlite3changeset_finalize(pIter);
  }else{
    sqlite3changeset_finalize(pIter);
  }

  if( rc==SQLITE_OK ){
    int nFk = sqlite3_foreign_key_check(db);
    if( nFk>0 ){
      int res = SQLITE_CHANGESET_ABORT;
      if( xConflict ){
        sqlite3_changeset_iter sIter;
        memset(&sIter, 0, sizeof(sIter));
        sIter.nCol = nFk;
        res = xConflict(pCtx, SQLITE_CHANGESET_FOREIGN_KEY, &sIter);
      }
      if( res!=SQLITE_CHANGESET_OMIT ){
        rc = SQLITE_CONSTRAINT;
      }
    }
  }
  sqlite3_exec(db, "PRAGMA defer_foreign_keys = 0", 0, 0, 0);

  if( rc==SQLITE_OK ){
    rc = sqlite3_exec(db, "RELEASE changeset_apply", 0, 0, 0);
  }else{
    sqlite3_exec(db, "ROLLBACK TO changeset_apply", 0, 0, 0);
    sqlite3_exec(db, "RELEASE changeset_apply", 0, 0, 0);
  }

*/
int sqlite3changeset_conflict(
  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
  int iVal,                       /* Column number */
  sqlite3_value **ppValue         /* OUT: Value from conflicting row */
);

/*
** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
**
** This function may only be called with an iterator passed to an
** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
** it sets the output variable to the total number of known foreign key
** violations in the destination database and returns SQLITE_OK.
**
** In all other cases this function returns SQLITE_MISUSE.
*/
int sqlite3changeset_fk_conflicts(
  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
  int *pnOut                      /* OUT: Number of FK violations */
);


/*
** CAPI3REF: Finalize A Changeset Iterator
**
** This function is used to finalize an iterator allocated with
** [sqlite3changeset_start()].
**

** <dt>SQLITE_CHANGESET_CONFLICT<dd>
**   CHANGESET_CONFLICT is passed as the second argument to the conflict
**   handler while processing an INSERT change if the operation would result 
**   in duplicate primary key values.
** 
**   The conflicting row in this case is the database row with the matching
**   primary key.
**
** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
**   If foreign key handling is enabled, and applying a changeset leaves the
**   database in a state containing foreign key violations, the conflict 
**   handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
**   exactly once before the changeset is committed. If the conflict handler
**   returns CHANGESET_OMIT, the changes, including those that caused the
**   foreign key constraint violation, are committed. Or, if it returns
**   CHANGESET_ABORT, the changeset is rolled back.
**
**   No current or conflicting row information is provided. The only function
**   it is possible to call on the supplied sqlite3_changeset_iter handle
**   is sqlite3changeset_fk_conflicts().
** 
** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
**   If any other constraint violation occurs while applying a change (i.e. 
**   a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 
**   invoked with CHANGESET_CONSTRAINT as the second argument.
** 
**   There is no conflicting row in this case. The results of invoking the
**   sqlite3changeset_conflict() API are undefined.
**
** </dl>
*/
#define SQLITE_CHANGESET_DATA        1
#define SQLITE_CHANGESET_NOTFOUND    2
#define SQLITE_CHANGESET_CONFLICT    3
#define SQLITE_CHANGESET_CONSTRAINT  4
#define SQLITE_CHANGESET_FOREIGN_KEY 5

/* 
** CAPI3REF: Constants Returned By The Conflict Handler
**
** A conflict handler callback must return one of the following three values.
**
** <dl>

  int nCol;                       /* Number of columns in table zTab */

  pEval = Tcl_DuplicateObj(p->pConflictScript);
  Tcl_IncrRefCount(pEval);

  sqlite3changeset_op(pIter, &zTab, &nCol, &op, 0);

  if( eConf==SQLITE_CHANGESET_FOREIGN_KEY ){
    int nFk;
    sqlite3changeset_fk_conflicts(pIter, &nFk);
    Tcl_ListObjAppendElement(0, pEval, Tcl_NewStringObj("FOREIGN_KEY", -1));
    Tcl_ListObjAppendElement(0, pEval, Tcl_NewIntObj(nFk));
  }else{

    /* Append the operation type. */
    Tcl_ListObjAppendElement(0, pEval, Tcl_NewStringObj(
        op==SQLITE_INSERT ? "INSERT" :
        op==SQLITE_UPDATE ? "UPDATE" : 
        "DELETE", -1
    ));
  
    /* Append the table name. */
    Tcl_ListObjAppendElement(0, pEval, Tcl_NewStringObj(zTab, -1));
  
    /* Append the conflict type. */
    switch( eConf ){
      case SQLITE_CHANGESET_DATA:
        Tcl_ListObjAppendElement(interp, pEval,Tcl_NewStringObj("DATA",-1));
        break;
      case SQLITE_CHANGESET_NOTFOUND:
        Tcl_ListObjAppendElement(interp, pEval,Tcl_NewStringObj("NOTFOUND",-1));
        break;
      case SQLITE_CHANGESET_CONFLICT:
        Tcl_ListObjAppendElement(interp, pEval,Tcl_NewStringObj("CONFLICT",-1));
        break;
      case SQLITE_CHANGESET_CONSTRAINT:
        Tcl_ListObjAppendElement(interp, pEval,Tcl_NewStringObj("CONSTRAINT",-1));
        break;
    }
  
    /* If this is not an INSERT, append the old row */
    if( op!=SQLITE_INSERT ){
      int i;
      Tcl_Obj *pOld = Tcl_NewObj();
      for(i=0; i<nCol; i++){
        sqlite3_value *pVal;
        sqlite3changeset_old(pIter, i, &pVal);
        test_append_value(pOld, pVal);
      }
      Tcl_ListObjAppendElement(0, pEval, pOld);
    }

    /* If this is not a DELETE, append the new row */
    if( op!=SQLITE_DELETE ){
      int i;
      Tcl_Obj *pNew = Tcl_NewObj();
      for(i=0; i<nCol; i++){
        sqlite3_value *pVal;
        sqlite3changeset_new(pIter, i, &pVal);
        test_append_value(pNew, pVal);
      }
      Tcl_ListObjAppendElement(0, pEval, pNew);
    }

    /* If this is a CHANGESET_DATA or CHANGESET_CONFLICT conflict, append
     ** the conflicting row.  */
    if( eConf==SQLITE_CHANGESET_DATA || eConf==SQLITE_CHANGESET_CONFLICT ){
      int i;
      Tcl_Obj *pConflict = Tcl_NewObj();
      for(i=0; i<nCol; i++){
        int rc;
        sqlite3_value *pVal;
        rc = sqlite3changeset_conflict(pIter, i, &pVal);
        assert( rc==SQLITE_OK );
        test_append_value(pConflict, pVal);
      }
      Tcl_ListObjAppendElement(0, pEval, pConflict);
    }

    /***********************************************************************
     ** This block is purely for testing some error conditions.
     */
    if( eConf==SQLITE_CHANGESET_CONSTRAINT 
     || eConf==SQLITE_CHANGESET_NOTFOUND 
    ){
      sqlite3_value *pVal;
      int rc = sqlite3changeset_conflict(pIter, 0, &pVal);
      assert( rc==SQLITE_MISUSE );
    }else{
      sqlite3_value *pVal;
      int rc = sqlite3changeset_conflict(pIter, -1, &pVal);
      assert( rc==SQLITE_RANGE );
      rc = sqlite3changeset_conflict(pIter, nCol, &pVal);
      assert( rc==SQLITE_RANGE );
    }
    if( op==SQLITE_DELETE ){
      sqlite3_value *pVal;
      int rc = sqlite3changeset_new(pIter, 0, &pVal);
      assert( rc==SQLITE_MISUSE );
    }else{
      sqlite3_value *pVal;
      int rc = sqlite3changeset_new(pIter, -1, &pVal);
      assert( rc==SQLITE_RANGE );
      rc = sqlite3changeset_new(pIter, nCol, &pVal);
      assert( rc==SQLITE_RANGE );
    }
    if( op==SQLITE_INSERT ){
      sqlite3_value *pVal;
      int rc = sqlite3changeset_old(pIter, 0, &pVal);
      assert( rc==SQLITE_MISUSE );
    }else{
      sqlite3_value *pVal;
      int rc = sqlite3changeset_old(pIter, -1, &pVal);
      assert( rc==SQLITE_RANGE );
      rc = sqlite3changeset_old(pIter, nCol, &pVal);
      assert( rc==SQLITE_RANGE );
    }
    /* End of testing block
    ***********************************************************************/
  }

  if( TCL_OK!=Tcl_EvalObjEx(interp, pEval, TCL_EVAL_GLOBAL) ){
    Tcl_BackgroundError(interp);
  }else{
    Tcl_Obj *pRes = Tcl_GetObjResult(interp);
    if( test_obj_eq_string(pRes, "OMIT") || test_obj_eq_string(pRes, "") ){
      ret = SQLITE_CHANGESET_OMIT;

      sqlite3VdbeAddOp4Int(v, OP_Found, iCur, iOk, regRec, 0);
  
      sqlite3ReleaseTempReg(pParse, regRec);
      sqlite3ReleaseTempRange(pParse, regTemp, nCol);
    }
  }

  if( !pFKey->isDeferred 
   && !pParse->pToplevel 
   && !pParse->isMultiWrite 
   && !(pParse->db->flags & SQLITE_DeferForeignKeys)
  ){
    /* Special case: If this is an INSERT statement that will insert exactly
    ** one row into the table, raise a constraint immediately instead of
    ** incrementing a counter. This is necessary as the VM code is being
    ** generated for will not open a statement transaction.  */
    assert( nIncr==1 );
    sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_FOREIGNKEY,
        OE_Abort, "foreign key constraint failed", P4_STATIC

    sqlite3ExpirePreparedStatements(db);
    sqlite3ResetAllSchemasOfConnection(db);
  }
  sqlite3BtreeLeaveAll(db);

  /* Any deferred constraint violations have now been resolved. */
  db->nDeferredCons = 0;
  db->nDeferredImmCons = 0;
  db->flags &= ~SQLITE_DeferForeignKeys;

  /* If one has been configured, invoke the rollback-hook callback */
  if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
    db->xRollbackCallback(db->pRollbackArg);
  }
}

          }
          ++i;
          pFK = pFK->pNextFrom;
        }
      }
    }
  }else

  if( sqlite3StrICmp(zLeft, "defer_foreign_keys")==0 ){
    if( zRight ){
      if( sqlite3GetBoolean(zRight, 0) ){
        db->flags |= SQLITE_DeferForeignKeys;
      }else{
        db->flags &= ~SQLITE_DeferForeignKeys;
        db->nDeferredImmCons = 0;
      }
      sqlite3VdbeAddOp2(v, OP_Expire, 0, 0);
    }else{
      int bVal = !!(db->flags & SQLITE_DeferForeignKeys);
      returnSingleInt(pParse, "defer_foreign_keys", bVal);
    }
  }
#endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */

#ifndef SQLITE_OMIT_FOREIGN_KEY
#ifndef SQLITE_OMIT_TRIGGER
  if( sqlite3StrICmp(zLeft, "foreign_key_check")==0 ){
    FKey *pFK;             /* A foreign key constraint */
    Table *pTab;           /* Child table contain "REFERENCES" keyword */

  ),
  void*
);
SQLITE_EXPERIMENTAL int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
SQLITE_EXPERIMENTAL int sqlite3_preupdate_count(sqlite3 *);
SQLITE_EXPERIMENTAL int sqlite3_preupdate_depth(sqlite3 *);
SQLITE_EXPERIMENTAL int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);

int sqlite3_foreign_key_check(sqlite3 *db);

/*
** Undo the hack that converts floating point types to integer for
** builds on processors without floating point support.
*/
#ifdef SQLITE_OMIT_FLOATING_POINT
# undef double

  BusyHandler busyHandler;      /* Busy callback */
  Db aDbStatic[2];              /* Static space for the 2 default backends */
  Savepoint *pSavepoint;        /* List of active savepoints */
  int busyTimeout;              /* Busy handler timeout, in msec */
  int nSavepoint;               /* Number of non-transaction savepoints */
  int nStatement;               /* Number of nested statement-transactions  */
  i64 nDeferredCons;            /* Net deferred constraints this transaction. */
  i64 nDeferredImmCons;         /* Net deferred immediate constraints */
  int *pnBytesFreed;            /* If not NULL, increment this in DbFree() */

#ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
  /* The following variables are all protected by the STATIC_MASTER 
  ** mutex, not by sqlite3.mutex. They are used by code in notify.c. 
  **
  ** When X.pUnlockConnection==Y, that means that X is waiting for Y to

#define SQLITE_ReverseOrder   0x00010000  /* Reverse unordered SELECTs */
#define SQLITE_RecTriggers    0x00020000  /* Enable recursive triggers */
#define SQLITE_ForeignKeys    0x00040000  /* Enforce foreign key constraints  */
#define SQLITE_AutoIndex      0x00080000  /* Enable automatic indexes */
#define SQLITE_PreferBuiltin  0x00100000  /* Preference to built-in funcs */
#define SQLITE_LoadExtension  0x00200000  /* Enable load_extension */
#define SQLITE_EnableTrigger  0x00400000  /* True to enable triggers */
#define SQLITE_DeferForeignKeys 0x00800000

/*
** Bits of the sqlite3.dbOptFlags field that are used by the
** sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS,...) interface to
** selectively disable various optimizations.
*/
#define SQLITE_QueryFlattener 0x0001   /* Query flattening */

** sqlite3.pSavepoint. The first element in the list is the most recently
** opened savepoint. Savepoints are added to the list by the vdbe
** OP_Savepoint instruction.
*/
struct Savepoint {
  char *zName;                        /* Savepoint name (nul-terminated) */
  i64 nDeferredCons;                  /* Number of deferred fk violations */
  i64 nDeferredImmCons;               /* Number of deferred imm fk. */
  Savepoint *pNext;                   /* Parent savepoint (if any) */
};

/*
** The following are used as the second parameter to sqlite3Savepoint(),
** and as the P1 argument to the OP_Savepoint instruction.
*/

  }
  rc = sqlite3VdbeHalt(p);
  assert( rc==SQLITE_BUSY || rc==SQLITE_OK || rc==SQLITE_ERROR );
  if( rc==SQLITE_BUSY ){
    p->rc = rc = SQLITE_BUSY;
  }else{
    assert( rc==SQLITE_OK || (p->rc&0xff)==SQLITE_CONSTRAINT );
    assert( rc==SQLITE_OK || db->nDeferredCons>0 || db->nDeferredImmCons>0 );
    rc = p->rc ? SQLITE_ERROR : SQLITE_DONE;
  }
  goto vdbe_return;
}

/* Opcode: Integer P1 P2 * * *
**

          db->nSavepoint++;
        }

        /* Link the new savepoint into the database handle's list. */
        pNew->pNext = db->pSavepoint;
        db->pSavepoint = pNew;
        pNew->nDeferredCons = db->nDeferredCons;
        pNew->nDeferredImmCons = db->nDeferredImmCons;
      }
    }
  }else{
    iSavepoint = 0;

    /* Find the named savepoint. If there is no such savepoint, then an
    ** an error is returned to the user.  */

        db->pSavepoint = pSavepoint->pNext;
        sqlite3DbFree(db, pSavepoint);
        if( !isTransaction ){
          db->nSavepoint--;
        }
      }else{
        db->nDeferredCons = pSavepoint->nDeferredCons;
        db->nDeferredImmCons = pSavepoint->nDeferredImmCons;
      }

      if( !isTransaction ){
        rc = sqlite3VtabSavepoint(db, p1, iSavepoint);
        if( rc!=SQLITE_OK ) goto abort_due_to_error;
      }
    }

        rc = sqlite3BtreeBeginStmt(pBt, p->iStatement);
      }

      /* Store the current value of the database handles deferred constraint
      ** counter. If the statement transaction needs to be rolled back,
      ** the value of this counter needs to be restored too.  */
      p->nStmtDefCons = db->nDeferredCons;
      p->nStmtDefImmCons = db->nDeferredImmCons;
    }
  }
  break;
}

/* Opcode: ReadCookie P1 P2 P3 * *
**

**
** Increment a "constraint counter" by P2 (P2 may be negative or positive).
** If P1 is non-zero, the database constraint counter is incremented 
** (deferred foreign key constraints). Otherwise, if P1 is zero, the 
** statement counter is incremented (immediate foreign key constraints).
*/
case OP_FkCounter: {
  if( db->flags & SQLITE_DeferForeignKeys ){
    db->nDeferredImmCons += pOp->p2;
  }else if( pOp->p1 ){
    db->nDeferredCons += pOp->p2;
  }else{
    p->nFkConstraint += pOp->p2;
  }
  break;
}

/* Opcode: FkIfZero P1 P2 * * *
**
** This opcode tests if a foreign key constraint-counter is currently zero.
** If so, jump to instruction P2. Otherwise, fall through to the next 
** instruction.
**
** If P1 is non-zero, then the jump is taken if the database constraint-counter
** is zero (the one that counts deferred constraint violations). If P1 is
** zero, the jump is taken if the statement constraint-counter is zero
** (immediate foreign key constraint violations).
*/
case OP_FkIfZero: {         /* jump */
  if( pOp->p1 ){
    if( db->nDeferredCons==0 && db->nDeferredImmCons==0 ) pc = pOp->p2-1;
  }else{
    if( p->nFkConstraint==0 && db->nDeferredImmCons==0 ) pc = pOp->p2-1;
  }
  break;
}
#endif /* #ifndef SQLITE_OMIT_FOREIGN_KEY */

#ifndef SQLITE_OMIT_AUTOINCREMENT
/* Opcode: MemMax P1 P2 * * *

  int iStatement;         /* Statement number (or 0 if has not opened stmt) */
  int aCounter[4];        /* Counters used by sqlite3_stmt_status() */
#ifndef SQLITE_OMIT_TRACE
  i64 startTime;          /* Time when query started - used for profiling */
#endif
  i64 nFkConstraint;      /* Number of imm. FK constraints this VM */
  i64 nStmtDefCons;       /* Number of def. constraints when stmt started */
  i64 nStmtDefImmCons;    /* Number of def. imm constraints when stmt started */
  char *zSql;             /* Text of the SQL statement that generated this */
  void *pFree;            /* Free this when deleting the vdbe */
#ifdef SQLITE_DEBUG
  FILE *trace;            /* Write an execution trace here, if not NULL */
#endif
#ifdef SQLITE_ENABLE_TREE_EXPLAIN
  Explain *pExplain;      /* The explainer */

    ** reset the interrupt flag.  This prevents a call to sqlite3_interrupt
    ** from interrupting a statement that has not yet started.
    */
    if( db->activeVdbeCnt==0 ){
      db->u1.isInterrupted = 0;
    }

    assert( db->writeVdbeCnt>0 || db->autoCommit==0 
        || (db->nDeferredCons==0 && db->nDeferredImmCons==0)
    );

#ifndef SQLITE_OMIT_TRACE
    if( db->xProfile && !db->init.busy ){
      sqlite3OsCurrentTimeInt64(db->pVfs, &p->startTime);
    }
#endif

  *ppValue = pMem;

 preupdate_new_out:
  sqlite3Error(db, rc, 0);
  return sqlite3ApiExit(db, rc);
}
#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */

int sqlite3_foreign_key_check(sqlite3 *db){ return db->nDeferredImmCons; }

    }

    /* If the statement transaction is being rolled back, also restore the 
    ** database handles deferred constraint counter to the value it had when 
    ** the statement transaction was opened.  */
    if( eOp==SAVEPOINT_ROLLBACK ){
      db->nDeferredCons = p->nStmtDefCons;
      db->nDeferredImmCons = p->nStmtDefImmCons;
    }
  }
  return rc;
}

/*
** This function is called when a transaction opened by the database 
** handle associated with the VM passed as an argument is about to be 
** committed. If there are outstanding deferred foreign key constraint
** violations, return SQLITE_ERROR. Otherwise, SQLITE_OK.
**
** If there are outstanding FK violations and this function returns 
** SQLITE_ERROR, set the result of the VM to SQLITE_CONSTRAINT_FOREIGNKEY
** and write an error message to it. Then return SQLITE_ERROR.
*/
#ifndef SQLITE_OMIT_FOREIGN_KEY
int sqlite3VdbeCheckFk(Vdbe *p, int deferred){
  sqlite3 *db = p->db;
  if( (deferred && (db->nDeferredCons+db->nDeferredImmCons)>0) 
   || (!deferred && p->nFkConstraint>0) 
  ){
    p->rc = SQLITE_CONSTRAINT_FOREIGNKEY;
    p->errorAction = OE_Abort;
    sqlite3SetString(&p->zErrMsg, db, "foreign key constraint failed");
    return SQLITE_ERROR;
  }
  return SQLITE_OK;
}

          sqlite3VdbeLeave(p);
          return SQLITE_BUSY;
        }else if( rc!=SQLITE_OK ){
          p->rc = rc;
          sqlite3RollbackAll(db, SQLITE_OK);
        }else{
          db->nDeferredCons = 0;
          db->nDeferredImmCons = 0;
          db->flags &= ~SQLITE_DeferForeignKeys;
          sqlite3CommitInternalChanges(db);
        }
      }else{
        sqlite3RollbackAll(db, SQLITE_OK);
      }
      db->nStatement = 0;
    }else if( eStatementOp==0 ){