SQLite

TCCX += -I$(TOP)/ext/rtree -I$(TOP)/ext/icu -I$(TOP)/ext/fts3
TCCX += -I$(TOP)/ext/async

# Object files for the SQLite library.
#
LIBOBJ+= alter.o analyze.o attach.o auth.o \
         backup.o bitvec.o btmutex.o btree.o build.o \
         callback.o complete.o date.o delete.o expr.o fault.o fkey.o \
         fts3.o fts3_expr.o fts3_hash.o fts3_icu.o fts3_porter.o \
         fts3_tokenizer.o fts3_tokenizer1.o \
         func.o global.o hash.o \
         icu.o insert.o journal.o legacy.o loadext.o \
         main.o malloc.o mem0.o mem1.o mem2.o mem3.o mem5.o \
         memjournal.o \
         mutex.o mutex_noop.o mutex_os2.o mutex_unix.o mutex_w32.o \

** This routine just deletes the data structure.  It does not unlink
** the table data structure from the hash table.  But it does destroy
** memory structures of the indices and foreign keys associated with 
** the table.
*/
void sqlite3DeleteTable(Table *pTable){
  Index *pIndex, *pNext;

  sqlite3 *db;

  if( pTable==0 ) return;
  db = pTable->dbMem;
  testcase( db==0 );

  /* Do not delete the table until the reference count reaches zero. */

  */
  for(pIndex = pTable->pIndex; pIndex; pIndex=pNext){
    pNext = pIndex->pNext;
    assert( pIndex->pSchema==pTable->pSchema );
    sqlite3DeleteIndex(pIndex);
  }


  /* Delete any foreign keys attached to this table. */


  sqlite3FkDelete(pTable);



  /* Delete the Table structure itself.
  */
  sqliteResetColumnNames(pTable);
  sqlite3DbFree(db, pTable->zName);
  sqlite3DbFree(db, pTable->zColAff);
  sqlite3SelectDelete(db, pTable->pSelect);

    pTab->tabFlags |= autoInc*TF_Autoincrement;
  }else if( autoInc ){
#ifndef SQLITE_OMIT_AUTOINCREMENT
    sqlite3ErrorMsg(pParse, "AUTOINCREMENT is only allowed on an "
       "INTEGER PRIMARY KEY");
#endif
  }else{
    Index *p;
    p = sqlite3CreateIndex(pParse, 0, 0, 0, pList, onError, 0, 0, sortOrder, 0);
    if( p ){
      p->autoIndex = 2;
    }
    pList = 0;
  }

primary_key_exit:
  sqlite3ExprListDelete(pParse->db, pList);
  return;
}

  Token *pTo,          /* Name of the other table */
  ExprList *pToCol,    /* Columns in the other table */
  int flags            /* Conflict resolution algorithms. */
){
  sqlite3 *db = pParse->db;
#ifndef SQLITE_OMIT_FOREIGN_KEY
  FKey *pFKey = 0;
  FKey *pNextTo;
  Table *p = pParse->pNewTable;
  int nByte;
  int i;
  int nCol;
  char *z;

  assert( pTo!=0 );

      z += n+1;
    }
  }
  pFKey->isDeferred = 0;
  pFKey->deleteConf = (u8)(flags & 0xff);
  pFKey->updateConf = (u8)((flags >> 8 ) & 0xff);
  pFKey->insertConf = (u8)((flags >> 16 ) & 0xff);

  pNextTo = (FKey *)sqlite3HashInsert(&p->pSchema->fkeyHash, 
      pFKey->zTo, sqlite3Strlen30(pFKey->zTo), (void *)pFKey
  );
  if( pNextTo==pFKey ) goto fk_end;
  if( pNextTo ){
    assert( pNextTo->pPrevTo==0 );
    pFKey->pNextTo = pNextTo;
    pNextTo->pPrevTo = pFKey;
  }

  /* Link the foreign key to the table as the last step.
  */
  p->pFKey = pFKey;
  pFKey = 0;

fk_end:

** UNIQUE constraint.  If pTable and pIndex are NULL, use pParse->pNewTable
** as the table to be indexed.  pParse->pNewTable is a table that is
** currently being constructed by a CREATE TABLE statement.
**
** pList is a list of columns to be indexed.  pList will be NULL if this
** is a primary key or unique-constraint on the most recent column added
** to the table currently under construction.  
**
** If the index is created successfully, return a pointer to the new Index
** structure. This is used by sqlite3AddPrimaryKey() to mark the index
** as the tables primary key (Index.autoIndex==2).
*/
Index *sqlite3CreateIndex(
  Parse *pParse,     /* All information about this parse */
  Token *pName1,     /* First part of index name. May be NULL */
  Token *pName2,     /* Second part of index name. May be NULL */
  SrcList *pTblName, /* Table to index. Use pParse->pNewTable if 0 */
  ExprList *pList,   /* A list of columns to be indexed */
  int onError,       /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
  Token *pStart,     /* The CREATE token that begins this statement */
  Token *pEnd,       /* The ")" that closes the CREATE INDEX statement */
  int sortOrder,     /* Sort order of primary key when pList==NULL */
  int ifNotExist     /* Omit error if index already exists */
){
  Index *pRet = 0;     /* Pointer to return */
  Table *pTab = 0;     /* Table to be indexed */
  Index *pIndex = 0;   /* The index to be created */
  char *zName = 0;     /* Name of the index */
  int nName;           /* Number of characters in zName */
  int i, j;
  Token nullId;        /* Fake token for an empty ID list */
  DbFixer sFix;        /* For assigning database names to pTable */

      Index *pOther = pTab->pIndex;
      while( pOther->pNext && pOther->pNext->onError!=OE_Replace ){
        pOther = pOther->pNext;
      }
      pIndex->pNext = pOther->pNext;
      pOther->pNext = pIndex;
    }
    pRet = pIndex;
    pIndex = 0;
  }

  /* Clean up before exiting */
exit_create_index:
  if( pIndex ){
    sqlite3_free(pIndex->zColAff);
    sqlite3DbFree(db, pIndex);
  }
  sqlite3ExprListDelete(db, pList);
  sqlite3SrcListDelete(db, pTblName);
  sqlite3DbFree(db, zName);
  return pRet;
}

/*
** Fill the Index.aiRowEst[] array with default information - information
** to be used when we have not run the ANALYZE command.
**
** aiRowEst[0] is suppose to contain the number of elements in the index.

  sqlite3HashInit(&pSchema->tblHash);
  for(pElem=sqliteHashFirst(&temp1); pElem; pElem=sqliteHashNext(pElem)){
    Table *pTab = sqliteHashData(pElem);
    assert( pTab->dbMem==0 );
    sqlite3DeleteTable(pTab);
  }
  sqlite3HashClear(&temp1);
  sqlite3HashClear(&pSchema->fkeyHash);
  pSchema->pSeqTab = 0;
  pSchema->flags &= ~DB_SchemaLoaded;
}

/*
** Find and return the schema associated with a BTree.  Create
** a new one if necessary.

  }
  if( !p ){
    db->mallocFailed = 1;
  }else if ( 0==p->file_format ){
    sqlite3HashInit(&p->tblHash);
    sqlite3HashInit(&p->idxHash);
    sqlite3HashInit(&p->trigHash);
    sqlite3HashInit(&p->fkeyHash);
    p->enc = SQLITE_UTF8;
  }
  return p;
}

  /* Begin generating code.
  */
  v = sqlite3GetVdbe(pParse);
  if( v==0 ){
    goto delete_from_cleanup;
  }
  if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
  sqlite3BeginWriteOperation(pParse, 1, iDb);

  /* If we are trying to delete from a view, realize that view into
  ** a ephemeral table.
  */
#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
  if( isView ){
    sqlite3MaterializeView(pParse, pTab, pWhere, iCur);

  }

#ifndef SQLITE_OMIT_TRUNCATE_OPTIMIZATION
  /* Special case: A DELETE without a WHERE clause deletes everything.
  ** It is easier just to erase the whole table. Prior to version 3.6.5,
  ** this optimization caused the row change count (the value returned by 
  ** API function sqlite3_count_changes) to be set incorrectly.  */
  if( rcauth==SQLITE_OK && pWhere==0 && !pTrigger && !IsVirtual(pTab) 
   && 0==sqlite3FkRequired(pParse, pTab, 0)
  ){
    assert( !isView );
    sqlite3VdbeAddOp4(v, OP_Clear, pTab->tnum, iDb, memCnt,
                      pTab->zName, P4_STATIC);
    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
      assert( pIdx->pSchema==pTab->pSchema );
      sqlite3VdbeAddOp2(v, OP_Clear, pIdx->tnum, iDb);
    }

** This routine generates VDBE code that causes a single row of a
** single table to be deleted.
**
** The VDBE must be in a particular state when this routine is called.
** These are the requirements:
**
**   1.  A read/write cursor pointing to pTab, the table containing the row
**       to be deleted, must be opened as cursor number $iCur.
**
**   2.  Read/write cursors for all indices of pTab must be open as
**       cursor number base+i for the i-th index.
**
**   3.  The record number of the row to be deleted must be stored in
**       memory cell iRowid.
**

  ** (this can happen if a trigger program has already deleted it), do
  ** not attempt to delete it or fire any DELETE triggers.  */
  iLabel = sqlite3VdbeMakeLabel(v);
  sqlite3VdbeAddOp3(v, OP_NotExists, iCur, iLabel, iRowid);
 
  /* If there are any triggers to fire, allocate a range of registers to
  ** use for the old.* references in the triggers.  */
  if( sqlite3FkRequired(pParse, pTab, 0) || pTrigger ){
    u32 mask;                     /* Mask of OLD.* columns in use */
    int iCol;                     /* Iterator used while populating OLD.* */

    /* TODO: Could use temporary registers here. Also could attempt to
    ** avoid copying the contents of the rowid register.  */
    mask = sqlite3TriggerOldmask(pParse, pTrigger, 0, pTab, onconf);
    iOld = pParse->nMem+1;
    pParse->nMem += (1 + pTab->nCol);

    /* Populate the OLD.* pseudo-table register array. These values will be 
    ** used by any BEFORE and AFTER triggers that exist.  */
    sqlite3VdbeAddOp2(v, OP_Copy, iRowid, iOld);
    for(iCol=0; iCol<pTab->nCol; iCol++){
      if( 1 || mask==0xffffffff || mask&(1<<iCol) ){
        int iTarget = iOld + iCol + 1;
        sqlite3VdbeAddOp3(v, OP_Column, iCur, iCol, iTarget);
        sqlite3ColumnDefault(v, pTab, iCol, iTarget);
      }
    }

    /* Invoke BEFORE DELETE trigger programs. */
    sqlite3CodeRowTrigger(pParse, pTrigger, 
        TK_DELETE, 0, TRIGGER_BEFORE, pTab, -1, iOld, onconf, iLabel
    );

    /* Seek the cursor to the row to be deleted again. It may be that
    ** the BEFORE triggers coded above have already removed the row
    ** being deleted. Do not attempt to delete the row a second time, and 
    ** do not fire AFTER triggers.  */
    sqlite3VdbeAddOp3(v, OP_NotExists, iCur, iLabel, iRowid);

    /* Do FK processing. This call checks that any FK constraints that
    ** refer to this table (i.e. constraints attached to other tables) 
    ** are not violated by deleting this row.  */
    sqlite3FkCheck(pParse, pTab, 0, iOld, 0);
  }

  /* Delete the index and table entries. Skip this step if pTab is really
  ** a view (in which case the only effect of the DELETE statement is to
  ** fire the INSTEAD OF triggers).  */ 
  if( pTab->pSelect==0 ){
    sqlite3GenerateRowIndexDelete(pParse, pTab, iCur, 0);
    sqlite3VdbeAddOp2(v, OP_Delete, iCur, (count?OPFLAG_NCHANGE:0));
    if( count ){
      sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_STATIC);
    }
  }

  /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to
  ** handle rows (possibly in other tables) that refer via a foreign key
  ** to the row just deleted. */ 
  sqlite3FkActions(pParse, pTab, 0, iOld);

  /* Invoke AFTER DELETE trigger programs. */

  sqlite3CodeRowTrigger(pParse, pTrigger, 
      TK_DELETE, 0, TRIGGER_AFTER, pTab, -1, iOld, onconf, iLabel
  );


  /* Jump here if the row had already been deleted before any BEFORE
  ** trigger programs were invoked. Or if a trigger program throws a 
  ** RAISE(IGNORE) exception.  */
  sqlite3VdbeResolveLabel(v, iLabel);
}

/*
**
** 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 contains code used by the compiler to add foreign key
** support to compiled SQL statements.
*/
#include "sqliteInt.h"

#ifndef SQLITE_OMIT_FOREIGN_KEY

/*
** Deferred and Immediate FKs
** --------------------------
**
** Foreign keys in SQLite come in two flavours: deferred and immediate.
** If an immediate foreign key constraint is violated, an OP_Halt is 
** executed and the current statement transaction rolled back. If a 
** deferred foreign key constraint is violated, no action is taken 
** immediately. However if the application attempts to commit the 
** transaction before fixing the constraint violation, the attempt fails.
**
** Deferred constraints are implemented using a simple counter associated
** with the database handle. The counter is set to zero each time a 
** database transaction is opened. Each time a statement is executed 
** that causes a foreign key violation, the counter is incremented. Each
** time a statement is executed that removes an existing violation from
** the database, the counter is decremented. When the transaction is
** committed, the commit fails if the current value of the counter is
** greater than zero. This scheme has two big drawbacks:
**
**   * When a commit fails due to a deferred foreign key constraint, 
**     there is no way to tell which foreign constraint is not satisfied,
**     or which row it is not satisfied for.
**
**   * If the database contains foreign key violations when the 
**     transaction is opened, this may cause the mechanism to malfunction.
**
** Despite these problems, this approach is adopted as it seems simpler
** than the alternatives.
**
** INSERT operations:
**
**   I.1) For each FK for which the table is the referencing table, search
**        the referenced table for a match. If none is found, throw an 
**        exception for an immediate FK, or increment the counter for a
**        deferred FK.
**
**   I.2) For each deferred FK for which the table is the referenced table, 
**        search the referencing table for rows that correspond to the new
**        row in the referenced table. Decrement the counter for each row
**        found (as the constraint is now satisfied).
**
** DELETE operations:
**
**   D.1) For each deferred FK for which the table is the referencing table, 
**        search the referenced table for a row that corresponds to the 
**        deleted row in the referencing table. If such a row is not found, 
**        decrement the counter.
**
**   D.2) For each FK for which the table is the referenced table, search 
**        the referencing table for rows that correspond to the deleted row 
**        in the referenced table. For each found, throw an exception for an
**        immediate FK, or increment the counter for a deferred FK.
**
** UPDATE operations:
**
**   An UPDATE command requires that all 4 steps above are taken, but only
**   for FK constraints for which the affected columns are actually 
**   modified (values must be compared at runtime).
**
** Note that I.1 and D.1 are very similar operations, as are I.2 and D.2.
** This simplifies the implementation a bit.
**
** For the purposes of immediate FK constraints, the OR REPLACE conflict
** resolution is considered to delete rows before the new row is inserted.
** If a delete caused by OR REPLACE violates an FK constraint, an exception
** is thrown, even if the FK constraint would be satisfied after the new 
** row is inserted.
**
** TODO: How should dropping a table be handled? How should renaming a 
** table be handled?
*/

/*
** Query API Notes
** ---------------
**
** Before coding an UPDATE or DELETE row operation, the code-generator
** for those two operations needs to know whether or not the operation
** requires any FK processing and, if so, which columns of the original
** row are required by the FK processing VDBE code (i.e. if FKs were
** implemented using triggers, which of the old.* columns would be 
** accessed). No information is required by the code-generator before
** coding an INSERT operation.
**
*/

/*
** VDBE Calling Convention
** -----------------------
**
** Example:
**
**   For the following INSERT statement:
**
**     CREATE TABLE t1(a, b INTEGER PRIMARY KEY, c);
**     INSERT INTO t1 VALUES(1, 2, 3.1);
**
**   Register (x):        2    (type integer)
**   Register (x+1):      1    (type integer)
**   Register (x+2):      NULL (type NULL)
**   Register (x+3):      3.1  (type real)
*/

/*
** ON UPDATE and ON DELETE clauses
** -------------------------------
*/

/*
** Externally accessible module functions
** --------------------------------------
**
**   sqlite3FkRequired()
**   sqlite3FkOldmask()
**
**   sqlite3FkCheck()
**   sqlite3FkActions()
**
**   sqlite3FkDelete()
** 
*/

/*
** A foreign key constraint requires that the key columns in the referenced
** table are collectively subject to a UNIQUE or PRIMARY KEY constraint.
** Given that pTo is the referenced table for foreign key constraint
** pFKey, check that the columns in pTo are indeed subject to a such a
** constraint. If they are not, return non-zero and leave an error in pParse.
**
** If an error does not occur, return zero.
*/
static int locateFkeyIndex(
  Parse *pParse,                  /* Parse context to store any error in */
  Table *pTo,                     /* Referenced table */
  FKey *pFKey,                    /* Foreign key to find index for */
  Index **ppIdx,                  /* OUT: Unique index on referenced table */
  int **paiCol                    /* OUT: Map of index columns in pFKey */
){
  Index *pIdx = 0;
  int *aiCol = 0;
  int nCol = pFKey->nCol;
  char *zFirst = pFKey->aCol[0].zCol;

  /* The caller is responsible for zeroing output parameters. */
  assert( ppIdx && *ppIdx==0 );
  assert( !paiCol || *paiCol==0 );

  /* If this is a non-composite (single column) foreign key, check if it 
  ** maps to the INTEGER PRIMARY KEY of table pTo. If so, leave *ppIdx 
  ** and *paiCol set to zero and return early. 
  **
  ** Otherwise, for a composite foreign key (more than one column), allocate
  ** space for the aiCol array (returned via output parameter *paiCol).
  ** Non-composite foreign keys do not require the aiCol array.
  */
  if( nCol==1 ){
    /* The FK maps to the IPK if any of the following are true:
    **
    **   1) The FK is explicitly mapped to "rowid", "oid" or "_rowid_", or
    **   2) There is an explicit INTEGER PRIMARY KEY column and the FK is
    **      implicitly mapped to the primary key of table pTo, or
    **   3) The FK is explicitly mapped to a column declared as INTEGER
    **      PRIMARY KEY.
    */
    if( zFirst && sqlite3IsRowid(zFirst) ) return 0;
    if( pTo->iPKey>=0 ){
      if( !zFirst ) return 0;
      if( !sqlite3StrICmp(pTo->aCol[pTo->iPKey].zName, zFirst) ) return 0;
    }
  }else if( paiCol ){
    assert( nCol>1 );
    aiCol = (int *)sqlite3DbMallocRaw(pParse->db, nCol*sizeof(int));
    if( !aiCol ) return 1;
    *paiCol = aiCol;
  }

  for(pIdx=pTo->pIndex; pIdx; pIdx=pIdx->pNext){
    if( pIdx->nColumn==nCol && pIdx->onError!=OE_None ){ 
      /* pIdx is a UNIQUE index (or a PRIMARY KEY) and has the right number
      ** of columns. If each indexed column corresponds to a foreign key
      ** column of pFKey, then this index is a winner.  */

      if( zFirst==0 ){
        /* If zFirst is NULL, then this foreign key is implicitly mapped to 
        ** the PRIMARY KEY of table pTo. The PRIMARY KEY index may be 
        ** identified by the test (Index.autoIndex==2).  */
        if( pIdx->autoIndex==2 ){
          if( aiCol ) memcpy(aiCol, pIdx->aiColumn, sizeof(int)*nCol);
          break;
        }
      }else{
        /* If zFirst is non-NULL, then this foreign key was declared to
        ** map to an explicit list of columns in table pTo. Check if this
        ** index matches those columns.  */
        int i, j;
        for(i=0; i<nCol; i++){
          char *zIdxCol = pTo->aCol[pIdx->aiColumn[i]].zName;
          for(j=0; j<nCol; j++){
            if( sqlite3StrICmp(pFKey->aCol[j].zCol, zIdxCol)==0 ){
              if( aiCol ) aiCol[i] = pFKey->aCol[j].iFrom;
              break;
            }
          }
          if( j==nCol ) break;
        }
        if( i==nCol ) break;      /* pIdx is usable */
      }
    }
  }

  if( pParse && !pIdx ){
    sqlite3ErrorMsg(pParse, "foreign key mismatch");
    sqlite3DbFree(pParse->db, aiCol);
    return 1;
  }

  *ppIdx = pIdx;
  return 0;
}

static void fkCheckReference(
  Parse *pParse,        /* Parse context */
  int iDb,              /* Index of database housing pTab */
  Table *pTab,          /* Table referenced by FK pFKey */
  Index *pIdx,          /* Index ensuring uniqueness of FK in pTab */
  FKey *pFKey,          /* Foreign key to check */
  int *aiCol,           /* Map from FK column to referencing table column */
  int regData,          /* Address of array containing referencing row */
  int nIncr             /* If deferred FK, increment counter by this */
){
  int i;
  Vdbe *v = sqlite3GetVdbe(pParse);
  int iCur = pParse->nTab - 1;
  int iOk = sqlite3VdbeMakeLabel(v);

  assert( pFKey->isDeferred || nIncr==1 );

  /* Check if any of the key columns in the referencing table are 
  ** NULL. If any are, then the constraint is satisfied. No need
  ** to search for a matching row in the referenced table.  */
  for(i=0; i<pFKey->nCol; i++){
    int iReg = pFKey->aCol[i].iFrom + regData + 1;
    sqlite3VdbeAddOp2(v, OP_IsNull, iReg, iOk);
  }

  if( pIdx==0 ){
    /* If pIdx is NULL, then the foreign key constraint references the
    ** INTEGER PRIMARY KEY column in the referenced table (table pTab).  */
    int iReg = pFKey->aCol[0].iFrom + regData + 1;
    sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenRead);
    sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, iReg);
    sqlite3VdbeAddOp2(v, OP_Goto, 0, iOk);
    sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-2);
  }else{
    int regRec = sqlite3GetTempReg(pParse);
    KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);

    sqlite3VdbeAddOp3(v, OP_OpenRead, iCur, pIdx->tnum, iDb);
    sqlite3VdbeChangeP4(v, -1, (char*)pKey, P4_KEYINFO_HANDOFF);

    if( aiCol ){
      int nCol = pFKey->nCol;
      int regTemp = sqlite3GetTempRange(pParse, nCol);
      for(i=0; i<nCol; i++){ 
        sqlite3VdbeAddOp2(v, OP_SCopy, aiCol[i]+1+regData, regTemp+i);
      }
      sqlite3VdbeAddOp3(v, OP_MakeRecord, regTemp, nCol, regRec);
      sqlite3ReleaseTempRange(pParse, regTemp, nCol);
    }else{
      int iReg = pFKey->aCol[0].iFrom + regData + 1;
      sqlite3VdbeAddOp3(v, OP_MakeRecord, iReg, 1, regRec);
      sqlite3IndexAffinityStr(v, pIdx);
    }

    sqlite3VdbeAddOp3(v, OP_Found, iCur, iOk, regRec);
    sqlite3ReleaseTempReg(pParse, regRec);
  }

  if( pFKey->isDeferred ){
    assert( nIncr==1 || nIncr==-1 );
    sqlite3VdbeAddOp1(v, OP_DeferredCons, nIncr);
  }else{
    sqlite3HaltConstraint(
        pParse, OE_Abort, "foreign key constraint failed", P4_STATIC
    );
  }

  sqlite3VdbeResolveLabel(v, iOk);
}

static void fkScanReferences(
  Parse *pParse,                  /* Parse context */
  SrcList *pSrc,                  /* SrcList containing the table to scan */
  Index *pIdx,                    /* Foreign key index */
  FKey *pFKey,                    /* Foreign key relationship */
  int *aiCol,                     /* Map from FK to referenced table columns */
  int regData,                    /* Referenced table data starts here */
  int nIncr                       /* Amount to increment deferred counter by */
){
  sqlite3 *db = pParse->db;       /* Database handle */
  int i;                          /* Iterator variable */
  Expr *pWhere = 0;               /* WHERE clause to scan with */
  NameContext sNameContext;       /* Context used to resolve WHERE clause */
  WhereInfo *pWInfo;              /* Context used by sqlite3WhereXXX() */

  for(i=0; i<pFKey->nCol; i++){
    Expr *pLeft;                  /* Value from deleted row */
    Expr *pRight;                 /* Column ref to referencing table */
    Expr *pEq;                    /* Expression (pLeft = pRight) */
    int iCol;                     /* Index of column in referencing table */ 
    const char *zCol;             /* Name of column in referencing table */

    pLeft = sqlite3Expr(db, TK_REGISTER, 0);
    if( pLeft ){
      pLeft->iTable = (pIdx ? (regData+pIdx->aiColumn[i]+1) : regData);
    }
    iCol = aiCol ? aiCol[i] : pFKey->aCol[0].iFrom;
    if( iCol<0 ){
      zCol = "rowid";
    }else{
      zCol = pFKey->pFrom->aCol[iCol].zName;
    }
    pRight = sqlite3Expr(db, TK_ID, zCol);
    pEq = sqlite3PExpr(pParse, TK_EQ, pLeft, pRight, 0);
    pWhere = sqlite3ExprAnd(db, pWhere, pEq);
  }

  /* Resolve the references in the WHERE clause. */
  memset(&sNameContext, 0, sizeof(NameContext));
  sNameContext.pSrcList = pSrc;
  sNameContext.pParse = pParse;
  sqlite3ResolveExprNames(&sNameContext, pWhere);

  /* Create VDBE to loop through the entries in pSrc that match the WHERE
  ** clause. If the constraint is not deferred, throw an exception for
  ** each row found. Otherwise, for deferred constraints, increment the
  ** deferred constraint counter by nIncr for each row selected.  */
  pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0, 0);
  if( pFKey->isDeferred && nIncr ){
    assert( nIncr==1 || nIncr==-1 );
    sqlite3VdbeAddOp1(pParse->pVdbe, OP_DeferredCons, nIncr);
  }else{
    assert( nIncr==1 || nIncr==0 );
    sqlite3HaltConstraint(
      pParse, OE_Abort, "foreign key constraint failed", P4_STATIC
    );
  }
  sqlite3WhereEnd(pWInfo);

  /* Clean up the WHERE clause constructed above. */
  sqlite3ExprDelete(db, pWhere);
}

/*
** This function returns a pointer to the head of a linked list of FK
** constraints that refer to the table passed as an argument. For example,
** given the following schema:
**
**   CREATE TABLE t1(a PRIMARY KEY);
**   CREATE TABLE t2(b REFERENCES t1(a);
**
** Calling this function with table "t1" as an argument returns a pointer
** to the FKey structure representing the foreign key constraint on table
** "t2". Calling this function with "t2" as the argument would return a
** NULL pointer (as there are no FK constraints that refer to t2).
*/
static FKey *fkRefering(Table *pTab){
  int nName = sqlite3Strlen30(pTab->zName);
  return (FKey *)sqlite3HashFind(&pTab->pSchema->fkeyHash, pTab->zName, nName);
}

void sqlite3FkCheck(
  Parse *pParse,                  /* Parse context */
  Table *pTab,                    /* Row is being deleted from this table */ 
  ExprList *pChanges,             /* Changed columns if this is an UPDATE */
  int regOld,                     /* Previous row data is stored here */
  int regNew                      /* New row data is stored here */
){
  sqlite3 *db = pParse->db;       /* Database handle */
  Vdbe *v;                        /* VM to write code to */
  FKey *pFKey;                    /* Used to iterate through FKs */
  int iDb;                        /* Index of database containing pTab */
  const char *zDb;                /* Name of database containing pTab */

  assert( ( pChanges &&  regOld &&  regNew)           /* UPDATE operation */
       || (!pChanges && !regOld &&  regNew)           /* INSERT operation */
       || (!pChanges &&  regOld && !regNew)           /* DELETE operation */
  );

  /* If foreign-keys are disabled, this function is a no-op. */
  if( (db->flags&SQLITE_ForeignKeys)==0 ) return;

  v = sqlite3GetVdbe(pParse);
  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
  zDb = db->aDb[iDb].zName;

  /* Loop through all the foreign key constraints attached to the table. */
  for(pFKey=pTab->pFKey; pFKey; pFKey=pFKey->pNextFrom){
    Table *pTo;                   /* Table referenced by this FK */
    Index *pIdx = 0;              /* Index on key columns in pTo */
    int *aiCol = 0;

    if( pFKey->isDeferred==0 && regNew==0 ) continue;

    /* Find the table this foreign key references. Also find a unique 
    ** index on the referenced table that corresponds to the key columns. 
    ** If either of these things cannot be located, set an error in pParse
    ** and return early.  */
    pTo = sqlite3LocateTable(pParse, 0, pFKey->zTo, zDb);
    if( !pTo || locateFkeyIndex(pParse, pTo, pFKey, &pIdx, &aiCol) ) return;
    assert( pFKey->nCol==1 || (aiCol && pIdx) );

    /* If the key does not overlap with the pChanges list, skip this FK. */
    if( pChanges ){
      /* TODO */
    }

    /* Take a shared-cache advisory read-lock on the referenced table.
    ** Allocate a cursor to use to search the unique index on the FK 
    ** columns in the referenced table.  */
    sqlite3TableLock(pParse, iDb, pTo->tnum, 0, pTo->zName);
    pParse->nTab++;

    if( regOld!=0 && pFKey->isDeferred ){
      fkCheckReference(pParse, iDb, pTo, pIdx, pFKey, aiCol, regOld, -1);
    }
    if( regNew!=0 ){
      fkCheckReference(pParse, iDb, pTo, pIdx, pFKey, aiCol, regNew, +1);
    }

    sqlite3DbFree(db, aiCol);
  }

  /* Loop through all the foreign key constraints that refer to this table */
  for(pFKey = fkRefering(pTab); pFKey; pFKey=pFKey->pNextTo){
    int iGoto;                    /* Address of OP_Goto instruction */
    Index *pIdx = 0;              /* Foreign key index for pFKey */
    SrcList *pSrc;
    int *aiCol = 0;

    /* For immediate constraints, skip this scan if:
    **
    **   1) this is an INSERT operation, or
    **   2) an UPDATE operation and the FK action is a trigger-action, or
    **   3) a DELETE operation and the FK action is a trigger-action.
    **
    ** A "trigger-action" is one of CASCADE, SET DEFAULT or SET NULL.
    */
    if( pFKey->isDeferred==0 ){
      if( regOld==0 ) continue;                                     /* 1 */
      if( regNew!=0 && pFKey->updateConf>OE_Restrict ) continue;    /* 2 */
      if( regNew==0 && pFKey->deleteConf>OE_Restrict ) continue;    /* 3 */
    }

    if( locateFkeyIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ) return;
    assert( aiCol || pFKey->nCol==1 );

    /* Check if this update statement has modified any of the key columns
    ** for this foreign key constraint. If it has not, there is no need
    ** to search the referencing table for rows in violation. This is
    ** just an optimization. Things would work fine without this check.  */
    if( pChanges ){
      /* TODO */
    }

    /* Create a SrcList structure containing a single table (the table 
    ** the foreign key that refers to this table is attached to). This
    ** is required for the sqlite3WhereXXX() interface.  */
    pSrc = sqlite3SrcListAppend(db, 0, 0, 0);
    if( !pSrc ) return;
    pSrc->a->pTab = pFKey->pFrom;
    pSrc->a->pTab->nRef++;
    pSrc->a->iCursor = pParse->nTab++;

    /* If this is an UPDATE, and none of the columns associated with this
    ** FK have been modified, do not scan the referencing table. Unlike
    ** the compile-time test implemented above, this is not just an 
    ** optimization. It is required so that immediate foreign keys do not 
    ** throw exceptions when the user executes a statement like:
    **
    **     UPDATE refd_table SET refd_column = refd_column
    */
    if( pChanges ){
      int i;
      int iJump = sqlite3VdbeCurrentAddr(v) + pFKey->nCol + 1;
      for(i=0; i<pFKey->nCol; i++){
        int iOff = (pIdx ? pIdx->aiColumn[i] : -1) + 1;
        sqlite3VdbeAddOp3(v, OP_Ne, regOld+iOff, iJump, regNew+iOff);
      }
      iGoto = sqlite3VdbeAddOp0(v, OP_Goto);
    }

    if( regNew!=0 && pFKey->isDeferred ){
      fkScanReferences(pParse, pSrc, pIdx, pFKey, aiCol, regNew, -1);
    }
    if( regOld!=0 ){
      /* If there is a RESTRICT action configured for the current operation
      ** on the referenced table of this FK, then throw an exception 
      ** immediately if the FK constraint is violated, even if this is a
      ** deferred trigger. That's what RESTRICT means. To defer checking
      ** the constraint, the FK should specify NO ACTION (represented
      ** using OE_None). NO ACTION is the default.  */
      fkScanReferences(pParse, pSrc, pIdx, pFKey, aiCol, regOld, 
          (pChanges!=0 && pFKey->updateConf!=OE_Restrict)
       || (pChanges==0 && pFKey->deleteConf!=OE_Restrict)
      );
    }

    if( pChanges ){
      sqlite3VdbeJumpHere(v, iGoto);
    }
    sqlite3SrcListDelete(db, pSrc);
    sqlite3DbFree(db, aiCol);
  }
}

#define COLUMN_MASK(x) (((x)>31) ? 0xffffffff : ((u32)1<<(x)))

/*
** This function is called before generating code to update or delete a 
** row contained in table pTab. If the operation is an update, then 
** pChanges is a pointer to the list of columns to modify. If this is a 
** delete, then pChanges is NULL.
*/
u32 sqlite3FkOldmask(
  Parse *pParse,                  /* Parse context */
  Table *pTab,                    /* Table being modified */
  ExprList *pChanges              /* Non-NULL for UPDATE operations */
){
  u32 mask = 0;
  if( pParse->db->flags&SQLITE_ForeignKeys ){
    FKey *p;
    int i;
    for(p=pTab->pFKey; p; p=p->pNextFrom){
      if( pChanges || p->isDeferred ){
        for(i=0; i<p->nCol; i++) mask |= COLUMN_MASK(p->aCol[i].iFrom);
      }
    }
    for(p=fkRefering(pTab); p; p=p->pNextTo){
      Index *pIdx = 0;
      locateFkeyIndex(0, pTab, p, &pIdx, 0);
      if( pIdx ){
        for(i=0; i<pIdx->nColumn; i++) mask |= COLUMN_MASK(pIdx->aiColumn[i]);
      }
    }
  }
  return mask;
}

/*
** This function is called before generating code to update or delete a 
** row contained in table pTab. If the operation is an update, then 
** pChanges is a pointer to the list of columns to modify. If this is a 
** delete, then pChanges is NULL.
**
** If any foreign key processing will be required, this function returns
** true. If there is no foreign key related processing, this function 
** returns false.
*/
int sqlite3FkRequired(
  Parse *pParse,                  /* Parse context */
  Table *pTab,                    /* Table being modified */
  ExprList *pChanges              /* Non-NULL for UPDATE operations */
){
  if( pParse->db->flags&SQLITE_ForeignKeys ){
    FKey *p;
    for(p=pTab->pFKey; p; p=p->pNextFrom){
      if( pChanges || p->isDeferred ) return 1;
    }
    if( fkRefering(pTab) ) return 1;
  }
  return 0;
}

static Trigger *fkActionTrigger(
  Parse *pParse,
  Table *pTab,                    /* Table being updated or deleted from */
  FKey *pFKey,                    /* Foreign key to get action for */
  ExprList *pChanges              /* Change-list for UPDATE, NULL for DELETE */
){
  sqlite3 *db = pParse->db;       /* Database handle */
  int action;
  Trigger *pTrigger;

  if( pChanges ){
    action = pFKey->updateConf;
    pTrigger = pFKey->pOnUpdate;
  }else{
    action = pFKey->deleteConf;
    pTrigger = pFKey->pOnDelete;
  }

  assert( OE_SetNull>OE_Restrict && OE_SetDflt>OE_Restrict );
  assert( OE_Cascade>OE_Restrict && OE_None<OE_Restrict );

  if( action>OE_Restrict && !pTrigger ){
    char const *zFrom;            /* Name of referencing table */
    int nFrom;                    /* Length in bytes of zFrom */
    Index *pIdx = 0;
    int *aiCol = 0;
    TriggerStep *pStep;
    sqlite3 *dbMem = pTab->dbMem;
    Expr *pWhere = 0;
    ExprList *pList = 0;
    int i;

    if( locateFkeyIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ) return 0;
    assert( aiCol || pFKey->nCol==1 );

    assert( dbMem==0 || dbMem==pParse->db );
    zFrom = pFKey->pFrom->zName;
    nFrom = sqlite3Strlen30(zFrom);
    pTrigger = (Trigger *)sqlite3DbMallocZero(dbMem, 
        sizeof(Trigger) +         /* struct Trigger */
        sizeof(TriggerStep) +     /* Single step in trigger program */
        nFrom + 1                 /* Space for pStep->target.z */
    );
    if( !pTrigger ){
      pParse->db->mallocFailed = 1;
      return 0;
    }
    pStep = pTrigger->step_list = (TriggerStep *)&pTrigger[1];
    pStep->target.z = (char *)&pStep[1];
    pStep->target.n = nFrom;
    memcpy((char *)pStep->target.z, zFrom, nFrom);

    for(i=0; i<pFKey->nCol; i++){
      Expr *pEq;
      int iFromCol;               /* Idx of column in referencing table */
      Token tFromCol;             /* Name of column in referencing table */
      Token tToCol;               /* Name of column in referenced table */
      Token tOld = { "old", 3 };  /* Literal "old" token */
      Token tNew = { "new", 3 };  /* Literal "new" token */

      iFromCol = aiCol ? aiCol[i] : pFKey->aCol[0].iFrom;
      tToCol.z = pIdx ? pTab->aCol[pIdx->aiColumn[i]].zName : "oid";
      tFromCol.z = iFromCol<0 ? "oid" : pFKey->pFrom->aCol[iFromCol].zName;

      tToCol.n = sqlite3Strlen30(tToCol.z);
      tFromCol.n = sqlite3Strlen30(tFromCol.z);

      /* Create the expression "zFromCol = OLD.zToCol" */
      pEq = sqlite3PExpr(pParse, TK_EQ,
          sqlite3PExpr(pParse, TK_ID, 0, 0, &tFromCol),
          sqlite3PExpr(pParse, TK_DOT, 
            sqlite3PExpr(pParse, TK_ID, 0, 0, &tOld),
            sqlite3PExpr(pParse, TK_ID, 0, 0, &tToCol)
          , 0)
      , 0);
      pWhere = sqlite3ExprAnd(pParse->db, pWhere, pEq);

      if( action!=OE_Cascade || pChanges ){
        Expr *pNew;
        if( action==OE_Cascade ){
          pNew = sqlite3PExpr(pParse, TK_DOT, 
            sqlite3PExpr(pParse, TK_ID, 0, 0, &tNew),
            sqlite3PExpr(pParse, TK_ID, 0, 0, &tToCol)
          , 0);
        }else if( action==OE_SetDflt ){
          Expr *pDflt = pIdx ? 0 : pTab->aCol[pIdx->aiColumn[i]].pDflt;
          if( pDflt ){
            pNew = sqlite3ExprDup(db, pDflt, 0);
          }else{
            pNew = sqlite3PExpr(pParse, TK_NULL, 0, 0, 0);
          }
        }else{
          pNew = sqlite3PExpr(pParse, TK_NULL, 0, 0, 0);
        }
        pList = sqlite3ExprListAppend(pParse, pList, pNew);
        sqlite3ExprListSetName(pParse, pList, &tFromCol, 0);
      }
    }
    sqlite3DbFree(pParse->db, aiCol);

    pStep->pWhere = sqlite3ExprDup(dbMem, pWhere, EXPRDUP_REDUCE);
    pStep->pExprList = sqlite3ExprListDup(dbMem, pList, EXPRDUP_REDUCE);
    sqlite3ExprDelete(pParse->db, pWhere);
    sqlite3ExprListDelete(pParse->db, pList);

    pStep->op = (action!=OE_Cascade || pChanges) ? TK_UPDATE : TK_DELETE;
    pStep->pTrig = pTrigger;
    pTrigger->pSchema = pTab->pSchema;
    pTrigger->pTabSchema = pTab->pSchema;

    if( pChanges ){
      pFKey->pOnUpdate = pTrigger;
      pTrigger->op = TK_UPDATE;
      pStep->op = TK_UPDATE;
    }else{
      pFKey->pOnDelete = pTrigger;
      pTrigger->op = TK_DELETE;
      pStep->op = (action==OE_Cascade)?TK_DELETE:TK_UPDATE;
    }
  }

  return pTrigger;
}

static void fkTriggerDelete(sqlite3 *dbMem, Trigger *p){
  if( p ){
    TriggerStep *pStep = p->step_list;
    sqlite3ExprDelete(dbMem, pStep->pWhere);
    sqlite3ExprListDelete(dbMem, pStep->pExprList);
    sqlite3DbFree(dbMem, p);
  }
}

/*
** This function is called when deleting or updating a row to implement
** any required CASCADE, SET NULL or SET DEFAULT actions.
*/
void sqlite3FkActions(
  Parse *pParse,                  /* Parse context */
  Table *pTab,                    /* Table being updated or deleted from */
  ExprList *pChanges,             /* Change-list for UPDATE, NULL for DELETE */
  int regOld                      /* Address of array containing old row */
){
  /* If foreign-key support is enabled, iterate through all FKs that 
  ** refer to table pTab. If there is an action associated with the FK 
  ** for this operation (either update or delete), invoke the associated 
  ** trigger sub-program.  */
  if( pParse->db->flags&SQLITE_ForeignKeys ){
    FKey *pFKey;                  /* Iterator variable */
    for(pFKey = fkRefering(pTab); pFKey; pFKey=pFKey->pNextTo){
      Trigger *pAction = fkActionTrigger(pParse, pTab, pFKey, pChanges);
      if( pAction ){
        sqlite3CodeRowTriggerDirect(pParse, pAction, pTab, regOld, OE_Abort, 0);
      }
    }
  }
}

/*
** Free all memory associated with foreign key definitions attached to
** table pTab. Remove the deleted foreign keys from the Schema.fkeyHash
** hash table.
*/
void sqlite3FkDelete(Table *pTab){
  FKey *pFKey;                    /* Iterator variable */
  FKey *pNext;                    /* Copy of pFKey->pNextFrom */

  for(pFKey=pTab->pFKey; pFKey; pFKey=pNext){

    /* Remove the FK from the fkeyHash hash table. */
    if( pFKey->pPrevTo ){
      pFKey->pPrevTo->pNextTo = pFKey->pNextTo;
    }else{
      void *data = (void *)pFKey->pNextTo;
      const char *z = (data ? pFKey->pNextTo->zTo : pFKey->zTo);
      sqlite3HashInsert(&pTab->pSchema->fkeyHash, z, sqlite3Strlen30(z), data);
    }
    if( pFKey->pNextTo ){
      pFKey->pNextTo->pPrevTo = pFKey->pPrevTo;
    }

    /* Delete any triggers created to implement actions for this FK. */
    fkTriggerDelete(pTab->dbMem, pFKey->pOnDelete);
    fkTriggerDelete(pTab->dbMem, pFKey->pOnUpdate);

    /* Delete the memory allocated for the FK structure. */
    pNext = pFKey->pNextFrom;
    sqlite3DbFree(pTab->dbMem, pFKey);
  }
}

#endif

    }else
#endif
    {
      int isReplace;    /* Set to true if constraints may cause a replace */
      sqlite3GenerateConstraintChecks(pParse, pTab, baseCur, regIns, aRegIdx,
          keyColumn>=0, 0, onError, endOfLoop, &isReplace
      );
      sqlite3FkCheck(pParse, pTab, 0, 0, regIns);
      sqlite3CompleteInsertion(
          pParse, pTab, baseCur, regIns, aRegIdx, 0, appendFlag, isReplace==0
      );
    }
  }

  /* Update the count of rows that are inserted

        seenReplace = 1;
        break;
      }
    }
    sqlite3VdbeJumpHere(v, j3);
    sqlite3ReleaseTempReg(pParse, regR);
  }
  
  if( pbMayReplace ){
    *pbMayReplace = seenReplace;
  }
}

/*
** This routine generates code to finish the INSERT or UPDATE operation

  sqlite3VtabRollback(db);
  sqlite3EndBenignMalloc();

  if( db->flags&SQLITE_InternChanges ){
    sqlite3ExpirePreparedStatements(db);
    sqlite3ResetInternalSchema(db, 0);
  }

  /* Any deferred constraint violations have now been resolved. */
  db->nDeferredCons = 0;

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

id(A) ::= INDEXED(X).    {A = X;}

// The following directive causes tokens ABORT, AFTER, ASC, etc. to
// fallback to ID if they will not parse as their original value.
// This obviates the need for the "id" nonterminal.
//
%fallback ID
  ABORT ACTION AFTER ANALYZE ASC ATTACH BEFORE BEGIN BY CASCADE CAST COLUMNKW
  CONFLICT DATABASE DEFERRED DESC DETACH EACH END EXCLUSIVE EXPLAIN FAIL FOR
  IGNORE IMMEDIATE INITIALLY INSTEAD LIKE_KW MATCH NO PLAN
  QUERY KEY OF OFFSET PRAGMA RAISE RELEASE REPLACE RESTRICT ROW ROLLBACK
  SAVEPOINT TEMP TRIGGER VACUUM VIEW VIRTUAL
%ifdef SQLITE_OMIT_COMPOUND_SELECT
  EXCEPT INTERSECT UNION
%endif SQLITE_OMIT_COMPOUND_SELECT
  REINDEX RENAME CTIME_KW IF
  .

// The next group of rules parses the arguments to a REFERENCES clause
// that determine if the referential integrity checking is deferred or
// or immediate and which determine what action to take if a ref-integ
// check fails.
//
%type refargs {int}
refargs(A) ::= .                     { A = OE_None * 0x010101; }
refargs(A) ::= refargs(X) refarg(Y). { A = (X & ~Y.mask) | Y.value; }
%type refarg {struct {int value; int mask;}}
refarg(A) ::= MATCH nm.              { A.value = 0;     A.mask = 0x000000; }
refarg(A) ::= ON DELETE refact(X).   { A.value = X;     A.mask = 0x0000ff; }
refarg(A) ::= ON UPDATE refact(X).   { A.value = X<<8;  A.mask = 0x00ff00; }

%type refact {int}
refact(A) ::= SET NULL.              { A = OE_SetNull; }
refact(A) ::= SET DEFAULT.           { A = OE_SetDflt; }
refact(A) ::= CASCADE.               { A = OE_Cascade; }
refact(A) ::= RESTRICT.              { A = OE_Restrict; }
refact(A) ::= NO ACTION.             { A = OE_None; }
%type defer_subclause {int}
defer_subclause(A) ::= NOT DEFERRABLE init_deferred_pred_opt.     {A = 0;}
defer_subclause(A) ::= DEFERRABLE init_deferred_pred_opt(X).      {A = X;}
%type init_deferred_pred_opt {int}
init_deferred_pred_opt(A) ::= .                       {A = 0;}
init_deferred_pred_opt(A) ::= INITIALLY DEFERRED.     {A = 1;}
init_deferred_pred_opt(A) ::= INITIALLY IMMEDIATE.    {A = 0;}

// For the time being, the only constraint we care about is the primary

    { "writable_schema",          SQLITE_WriteSchema|SQLITE_RecoveryMode },
    { "omit_readlock",            SQLITE_NoReadlock    },

    /* TODO: Maybe it shouldn't be possible to change the ReadUncommitted
    ** flag if there are any active statements. */
    { "read_uncommitted",         SQLITE_ReadUncommitted },
    { "recursive_triggers",       SQLITE_RecTriggers },

    /* TODO: Prevent this flag from being set if not in auto-commit mode? */
    { "foreign_keys",             SQLITE_ForeignKeys },
  };
  int i;
  const struct sPragmaType *p;
  for(i=0, p=aPragma; i<ArraySize(aPragma); i++, p++){
    if( sqlite3StrICmp(zLeft, p->zName)==0 ){
      sqlite3 *db = pParse->db;
      Vdbe *v;

/*
** Return a human-readable name for a constraint resolution action.
*/
static const char *actionName(u8 action){
  const char *zName;
  switch( action ){
    case OE_SetNull:  zName = "SET NULL";        break;
    case OE_SetDflt:  zName = "SET DEFAULT";     break;
    case OE_Cascade:  zName = "CASCADE";         break;
    case OE_Restrict: zName = "RESTRICT";        break;
    default:          zName = "NO ACTION";  
                      assert( action==OE_None ); break;
  }
  return zName;
}

/*
** Process a pragma statement.  
**

      */
      "CREATE TRIGGER /name/_delete_referenced BEFORE DELETE ON /ref/ WHEN\n"
      "    EXISTS (SELECT 1 FROM /tbl/ WHERE /cond2/)\n"
      "BEGIN\n"
      "  /delete_action/\n"
      "END;\n"

      /* The "AFTER UPDATE ON <referenced>" trigger. This trigger's job 
      ** is to detect when the key columns of a row in the referenced table 
      ** to which one or more rows in the referencing table correspond are
      ** updated. The action taken depends on the value of the 'ON UPDATE' 
      ** clause.
      */
      "CREATE TRIGGER /name/_update_referenced AFTER\n"
      "    UPDATE OF /fkey_list/ ON /ref/ WHEN \n"

** statements.
*/
struct Schema {
  int schema_cookie;   /* Database schema version number for this file */
  Hash tblHash;        /* All tables indexed by name */
  Hash idxHash;        /* All (named) indices indexed by name */
  Hash trigHash;       /* All triggers indexed by name */
  Hash fkeyHash;       /* All foreign keys by referenced table name */
  Table *pSeqTab;      /* The sqlite_sequence table used by AUTOINCREMENT */
  u8 file_format;      /* Schema format version for this file */
  u8 enc;              /* Text encoding used by this database */
  u16 flags;           /* Flags associated with this schema */
  int cache_size;      /* Number of pages to use in the cache */
#ifndef SQLITE_OMIT_VIRTUALTABLE
  sqlite3 *db;         /* "Owner" connection. See comment above */

  BusyHandler busyHandler;      /* Busy callback */
  int busyTimeout;              /* Busy handler timeout, in msec */
  Db aDbStatic[2];              /* Static space for the 2 default backends */
  Savepoint *pSavepoint;        /* List of active savepoints */
  int nSavepoint;               /* Number of non-transaction savepoints */
  int nStatement;               /* Number of nested statement-transactions  */
  u8 isTransactionSavepoint;    /* True if the outermost savepoint is a TS */
#ifndef SQLITE_OMIT_FOREIGN_KEY
  i64 nDeferredCons;            /* Net deferred constraints this transaction. */
#endif

#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
  ** unlock so that it can proceed.

#define SQLITE_LegacyFileFmt  0x00008000  /* Create new databases in format 1 */
#define SQLITE_FullFSync      0x00010000  /* Use full fsync on the backend */
#define SQLITE_LoadExtension  0x00020000  /* Enable load_extension */

#define SQLITE_RecoveryMode   0x00040000  /* Ignore schema errors */
#define SQLITE_ReverseOrder   0x00100000  /* Reverse unordered SELECTs */
#define SQLITE_RecTriggers    0x00200000  /* Enable recursive triggers */
#define SQLITE_ForeignKeys    0x00400000  /* Enforce foreign key constraints  */

/*
** Possible values for the sqlite.magic field.
** The numbers are obtained at random and have no special meaning, other
** than being distinct from one another.
*/
#define SQLITE_MAGIC_OPEN     0xa029a697  /* Database is open */

** All current savepoints are stored in a linked list starting at
** 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) */
  int nDeferredCons;                  /* Number of deferred fk violations */
  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.
*/

** which is attached to the from-table.  The to-table need not exist when
** the from-table is created.  The existence of the to-table is not checked.
*/
struct FKey {
  Table *pFrom;     /* The table that contains the REFERENCES clause */
  FKey *pNextFrom;  /* Next foreign key in pFrom */
  char *zTo;        /* Name of table that the key points to */
  FKey *pNextTo;    /* Next foreign key on table named zTo */
  FKey *pPrevTo;    /* Previous foreign key on table named zTo */
  int nCol;         /* Number of columns in this key */
  u8 isDeferred;    /* True if constraint checking is deferred till COMMIT */
  u8 updateConf;    /* How to resolve conflicts that occur on UPDATE */
  u8 deleteConf;    /* How to resolve conflicts that occur on DELETE */
  u8 insertConf;    /* How to resolve conflicts that occur on INSERT */
  Trigger *pOnUpdate;  /* Trigger for AFTER UPDATE ON zTo */
  Trigger *pOnDelete;  /* Trigger for AFTER DELETE ON zTo */
  struct sColMap {  /* Mapping of columns in pFrom to columns in zTo */
    int iFrom;         /* Index of column in pFrom */
    char *zCol;        /* Name of column in zTo.  If 0 use PRIMARY KEY */
  } aCol[1];        /* One entry for each of nCol column s */
};

/*

                                      Token*, Select*, Expr*, IdList*);
void sqlite3SrcListIndexedBy(Parse *, SrcList *, Token *);
int sqlite3IndexedByLookup(Parse *, struct SrcList_item *);
void sqlite3SrcListShiftJoinType(SrcList*);
void sqlite3SrcListAssignCursors(Parse*, SrcList*);
void sqlite3IdListDelete(sqlite3*, IdList*);
void sqlite3SrcListDelete(sqlite3*, SrcList*);
Index *sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
                        Token*, int, int);
void sqlite3DropIndex(Parse*, SrcList*, int);
int sqlite3Select(Parse*, Select*, SelectDest*);
Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
                         Expr*,ExprList*,int,Expr*,Expr*);
void sqlite3SelectDelete(sqlite3*, Select*);
Table *sqlite3SrcListLookup(Parse*, SrcList*);

  void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);
  void sqlite3DropTrigger(Parse*, SrcList*, int);
  void sqlite3DropTriggerPtr(Parse*, Trigger*);
  Trigger *sqlite3TriggersExist(Parse *, Table*, int, ExprList*, int *pMask);
  Trigger *sqlite3TriggerList(Parse *, Table *);
  void sqlite3CodeRowTrigger(Parse*, Trigger *, int, ExprList*, int, Table *,
                            int, int, int, int);
  void sqlite3CodeRowTriggerDirect(Parse *, Trigger *, Table *, int, int, int);
  void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
  void sqlite3DeleteTriggerStep(sqlite3*, TriggerStep*);
  TriggerStep *sqlite3TriggerSelectStep(sqlite3*,Select*);
  TriggerStep *sqlite3TriggerInsertStep(sqlite3*,Token*, IdList*,
                                        ExprList*,Select*,u8);
  TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, u8);
  TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
  void sqlite3DeleteTrigger(sqlite3*, Trigger*);
  void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
  u32 sqlite3TriggerOldmask(Parse*,Trigger*,ExprList*,Table*,int);
# define sqlite3ParseToplevel(p) ((p)->pToplevel ? (p)->pToplevel : (p))
#else
# define sqlite3TriggersExist(B,C,D,E,F) 0
# define sqlite3DeleteTrigger(A,B)
# define sqlite3DropTriggerPtr(A,B)
# define sqlite3UnlinkAndDeleteTrigger(A,B,C)
# define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I,J)
# define sqlite3TriggerList(X, Y) 0
# define sqlite3ParseToplevel(p) p
# define sqlite3TriggerOldmask(A,B,C,D,E) 0
#endif

int sqlite3JoinType(Parse*, Token*, Token*, Token*);
void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
void sqlite3DeferForeignKey(Parse*, int);
#ifndef SQLITE_OMIT_AUTHORIZATION
  void sqlite3AuthRead(Parse*,Expr*,Schema*,SrcList*);

int sqlite3TransferBindings(sqlite3_stmt *, sqlite3_stmt *);
int sqlite3Reprepare(Vdbe*);
void sqlite3ExprListCheckLength(Parse*, ExprList*, const char*);
CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);
int sqlite3TempInMemory(const sqlite3*);
VTable *sqlite3GetVTable(sqlite3*, Table*);

#ifndef SQLITE_OMIT_FOREIGN_KEY
  void sqlite3FkCheck(Parse*, Table*, ExprList*, int, int);
  void sqlite3FkActions(Parse*, Table*, ExprList*, int);
  void sqlite3FkDelete(Table*);
  int sqlite3FkRequired(Parse*, Table*, ExprList*);
  u32 sqlite3FkOldmask(Parse*, Table*, ExprList*);
#else
  #define sqlite3FkCheck(a,b,c,d,e)
  #define sqlite3FkActions(a,b,c,d)
  #define sqlite3FkDelete(a)
  #define sqlite3FkRequired(a,b,c) 0
  #define sqlite3FkOldmask(a,b,c)  0
#endif

/*
** Available fault injectors.  Should be numbered beginning with 0.
*/
#define SQLITE_FAULTINJECTOR_MALLOC     0
#define SQLITE_FAULTINJECTOR_COUNT      1

  Expr *pWhen = 0;            /* Duplicate of trigger WHEN expression */
  Vdbe *v;                    /* Temporary VM */
  NameContext sNC;            /* Name context for sub-vdbe */
  SubProgram *pProgram = 0;   /* Sub-vdbe for trigger program */
  Parse *pSubParse;           /* Parse context for sub-vdbe */
  int iEndTrigger = 0;        /* Label to jump to if WHEN is false */

  assert( pTrigger->zName==0 || pTab==tableOfTrigger(pTrigger) );

  /* Allocate the TriggerPrg and SubProgram objects. To ensure that they
  ** are freed if an error occurs, link them into the Parse.pTriggerPrg 
  ** list of the top-level Parse object sooner rather than later.  */
  pPrg = sqlite3DbMallocZero(db, sizeof(TriggerPrg));
  if( !pPrg ) return 0;
  pPrg->pNext = pTop->pTriggerPrg;

  Trigger *pTrigger,   /* Trigger to code */
  Table *pTab,         /* The table trigger pTrigger is attached to */
  int orconf           /* ON CONFLICT algorithm. */
){
  Parse *pRoot = sqlite3ParseToplevel(pParse);
  TriggerPrg *pPrg;

  assert( pTrigger->zName==0 || pTab==tableOfTrigger(pTrigger) );

  /* It may be that this trigger has already been coded (or is in the
  ** process of being coded). If this is the case, then an entry with
  ** a matching TriggerPrg.pTrigger field will be present somewhere
  ** in the Parse.pTriggerPrg list. Search for such an entry.  */
  for(pPrg=pRoot->pTriggerPrg; 
      pPrg && (pPrg->pTrigger!=pTrigger || pPrg->orconf!=orconf); 
      pPrg=pPrg->pNext
  );

  /* If an existing TriggerPrg could not be located, create a new one. */
  if( !pPrg ){
    pPrg = codeRowTrigger(pParse, pTrigger, pTab, orconf);
  }

  return pPrg;
}

void sqlite3CodeRowTriggerDirect(
  Parse *pParse,       /* Parse context */
  Trigger *p,          /* Trigger to code */
  Table *pTab,         /* The table to code triggers from */
  int oldIdx,          /* The indice of the "old" row to access */
  int orconf,          /* ON CONFLICT policy */
  int ignoreJump       /* Instruction to jump to for RAISE(IGNORE) */
){
  Vdbe *v = sqlite3GetVdbe(pParse); /* Main VM */
  TriggerPrg *pPrg;
  pPrg = getRowTrigger(pParse, p, pTab, orconf);
  assert( pPrg || pParse->nErr || pParse->db->mallocFailed );

  /* Code the OP_Program opcode in the parent VDBE. P4 of the OP_Program 
  ** is a pointer to the sub-vdbe containing the trigger program.  */
  if( pPrg ){
    sqlite3VdbeAddOp3(v, OP_Program, oldIdx, ignoreJump, ++pParse->nMem);
    pPrg->pProgram->nRef++;
    sqlite3VdbeChangeP4(v, -1, (const char *)pPrg->pProgram, P4_SUBPROGRAM);
    VdbeComment(
        (v, "Call: %s.%s", (p->zName?p->zName:"fkey"), onErrorText(orconf)));

    /* Set the P5 operand of the OP_Program instruction to non-zero if
    ** recursive invocation of this trigger program is disallowed. Recursive
    ** invocation is disallowed if (a) the sub-program is really a trigger,
    ** not a foreign key action, and (b) the flag to enable recursive triggers
    ** is clear.  */
    sqlite3VdbeChangeP5(v, p->zName && !(pParse->db->flags&SQLITE_RecTriggers));

  }
}

/*
** This is called to code FOR EACH ROW triggers.
**
** When the code that this function generates is executed, the following 
** must be true:
**

         || p->pSchema==pParse->db->aDb[1].pSchema );

    /* Determine whether we should code this trigger */
    if( p->op==op 
     && p->tr_tm==tr_tm 
     && checkColumnOverlap(p->pColumns,pChanges)
    ){




      sqlite3CodeRowTriggerDirect(pParse, p, pTab, oldIdx, orconf, ignoreJump);








    }
  }
}

/*
** Triggers fired by UPDATE or DELETE statements may access values stored
** in the old.* pseudo-table. This function returns a 32-bit bitmask

** by triggers. The caller must always assume that it is.
**
** There is no equivalent function for new.* references.
*/
u32 sqlite3TriggerOldmask(
  Parse *pParse,       /* Parse context */
  Trigger *pTrigger,   /* List of triggers on table pTab */

  ExprList *pChanges,  /* Changes list for any UPDATE OF triggers */
  Table *pTab,         /* The table to code triggers from */
  int orconf           /* Default ON CONFLICT policy for trigger steps */
){
  const int op = pChanges ? TK_UPDATE : TK_DELETE;
  u32 mask = 0;
  Trigger *p;


  for(p=pTrigger; p; p=p->pNext){
    if( p->op==op && checkColumnOverlap(p->pColumns,pChanges) ){
      TriggerPrg *pPrg;
      pPrg = getRowTrigger(pParse, p, pTab, orconf);
      if( pPrg ){
        mask |= pPrg->oldmask;
      }

  Expr *pRowidExpr = 0;  /* Expression defining the new record number */
  int openAll = 0;       /* True if all indices need to be opened */
  AuthContext sContext;  /* The authorization context */
  NameContext sNC;       /* The name-context to resolve expressions in */
  int iDb;               /* Database containing the table being updated */
  int j1;                /* Addresses of jump instructions */
  int okOnePass;         /* True for one-pass algorithm without the FIFO */
  int hasFK;             /* True if foreign key processing is required */

#ifndef SQLITE_OMIT_TRIGGER
  int isView;                  /* Trying to update a view */
  Trigger *pTrigger;           /* List of triggers on pTab, if required */
#endif


  /* Register Allocations */
  int regRowCount = 0;   /* A count of rows changed */
  int regOldRowid;       /* The old rowid */
  int regNewRowid;       /* The new rowid */
  int regNew;
  int regOld = 0;

# define pTrigger 0
# define isView 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif

  hasFK = sqlite3FkRequired(pParse, pTab, pChanges);

  if( sqlite3ViewGetColumnNames(pParse, pTab) ){
    goto update_cleanup;
  }
  if( sqlite3IsReadOnly(pParse, pTab, (pTrigger?1:0)) ){
    goto update_cleanup;
  }

    pTabList = 0;
    goto update_cleanup;
  }
#endif

  /* Allocate required registers. */
  regOldRowid = regNewRowid = ++pParse->nMem;
  if( pTrigger || hasFK ){
    regOld = pParse->nMem + 1;
    pParse->nMem += pTab->nCol;
  }
  if( chngRowid || pTrigger || hasFK ){
    regNewRowid = ++pParse->nMem;
  }
  regNew = pParse->nMem + 1;
  pParse->nMem += pTab->nCol;
  regRec = ++pParse->nMem;

  /* Start the view context. */
  if( isView ){
    sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
  }





  /* If we are trying to update a view, realize that view into
  ** a ephemeral table.
  */
#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
  if( isView ){
    sqlite3MaterializeView(pParse, pTab, pWhere, iCur);
  }

    addr = sqlite3VdbeAddOp3(v, OP_RowSetRead, regRowSet, 0, regOldRowid);
  }

  /* Make cursor iCur point to the record that is being updated. If
  ** this record does not exist for some reason (deleted by a trigger,
  ** for example, then jump to the next iteration of the RowSet loop.  */
  sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, regOldRowid);

  /* If the record number will change, set register regNewRowid to
  ** contain the new value. If the record number is not being modified,
  ** then regNewRowid is the same register as regOldRowid, which is
  ** already populated.  */
  assert( chngRowid || pTrigger || hasFK || regOldRowid==regNewRowid );
  if( chngRowid ){
    sqlite3ExprCode(pParse, pRowidExpr, regNewRowid);
    sqlite3VdbeAddOp1(v, OP_MustBeInt, regNewRowid);
  }

  /* If there are triggers on this table, populate an array of registers 
  ** with the required old.* column data.  */
  if( hasFK || pTrigger ){
    u32 oldmask = sqlite3FkOldmask(pParse, pTab, pChanges);
    oldmask |= sqlite3TriggerOldmask(pParse, pTrigger, pChanges, pTab, onError);
    for(i=0; i<pTab->nCol; i++){
      if( aXRef[i]<0 || oldmask==0xffffffff || (oldmask & (1<<i)) ){
        sqlite3VdbeAddOp3(v, OP_Column, iCur, i, regOld+i);
        sqlite3ColumnDefault(v, pTab, i, regOld+i);
      }else{
        sqlite3VdbeAddOp2(v, OP_Null, 0, regOld+i);
      }
    }







    if( chngRowid==0 ){



      sqlite3VdbeAddOp2(v, OP_Copy, regOldRowid, regNewRowid);
    }
  }

  /* Populate the array of registers beginning at regNew with the new
  ** row data. This array is used to check constaints, create the new
  ** table and index records, and as the values for any new.* references
  ** made by triggers.  */
  for(i=0; i<pTab->nCol; i++){

  if( !isView ){

    /* Do constraint checks. */
    sqlite3GenerateConstraintChecks(pParse, pTab, iCur, regNewRowid,
        aRegIdx, (chngRowid?regOldRowid:0), 1, onError, addr, 0);

    /* Do FK constraint checks. */
    sqlite3FkCheck(pParse, pTab, pChanges, regOldRowid, regNewRowid);

    /* Delete the index entries associated with the current record.  */
    j1 = sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, regOldRowid);
    sqlite3GenerateRowIndexDelete(pParse, pTab, iCur, aRegIdx);
  
    /* If changing the record number, delete the old record.  */
    if( chngRowid ){
      sqlite3VdbeAddOp2(v, OP_Delete, iCur, 0);
    }
    sqlite3VdbeJumpHere(v, j1);
  
    /* Insert the new index entries and the new record. */
    sqlite3CompleteInsertion(pParse, pTab, iCur, regNewRowid, aRegIdx, 1, 0, 0);

    /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to
    ** handle rows (possibly in other tables) that refer via a foreign key
    ** to the row just updated. */ 
    sqlite3FkActions(pParse, pTab, pChanges, regOldRowid);
  }

  /* Increment the row counter 
  */
  if( (db->flags & SQLITE_CountRows) && !pParse->pTriggerTab){
    sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);
  }

  p->rc = pOp->p1;
  p->errorAction = (u8)pOp->p2;
  p->pc = pc;
  if( pOp->p4.z ){
    sqlite3SetString(&p->zErrMsg, db, "%s", pOp->p4.z);
  }
  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==SQLITE_CONSTRAINT );
    assert( rc==SQLITE_OK || db->nDeferredCons>0 );
    rc = p->rc ? SQLITE_ERROR : SQLITE_DONE;
  }
  goto vdbe_return;
}

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

          db->isTransactionSavepoint = 1;
        }else{
          db->nSavepoint++;
        }
    
        /* Link the new savepoint into the database handle's list. */
        pNew->pNext = db->pSavepoint;
        pNew->nDeferredCons = db->nDeferredCons;
        db->pSavepoint = pNew;
      }
    }
  }else{
    iSavepoint = 0;

    /* Find the named savepoint. If there is no such savepoint, then an

      /* Determine whether or not this is a transaction savepoint. If so,
      ** and this is a RELEASE command, then the current transaction 
      ** is committed. 
      */
      int isTransaction = pSavepoint->pNext==0 && db->isTransactionSavepoint;
      if( isTransaction && p1==SAVEPOINT_RELEASE ){
        if( (rc = sqlite3VdbeCheckDeferred(p))!=SQLITE_OK ){
          goto vdbe_return;
        }
        db->autoCommit = 1;
        if( sqlite3VdbeHalt(p)==SQLITE_BUSY ){
          p->pc = pc;
          db->autoCommit = 0;
          p->rc = rc = SQLITE_BUSY;
          goto vdbe_return;
        }

      while( db->pSavepoint!=pSavepoint ){
        pTmp = db->pSavepoint;
        db->pSavepoint = pTmp->pNext;
        sqlite3DbFree(db, pTmp);
        db->nSavepoint--;
      }

      /* If it is a RELEASE, then destroy the savepoint being operated on 
      ** too. If it is a ROLLBACK TO, then set the number of deferred 
      ** constraint violations present in the database to the value stored
      ** when the savepoint was created.  */
      if( p1==SAVEPOINT_RELEASE ){
        assert( pSavepoint==db->pSavepoint );
        db->pSavepoint = pSavepoint->pNext;
        sqlite3DbFree(db, pSavepoint);
        if( !isTransaction ){
          db->nSavepoint--;
        }
      }else{
        db->nDeferredCons = pSavepoint->nDeferredCons;
      }
    }
  }

  break;
}

        "SQL statements in progress");
    rc = SQLITE_BUSY;
  }else if( desiredAutoCommit!=db->autoCommit ){
    if( iRollback ){
      assert( desiredAutoCommit==1 );
      sqlite3RollbackAll(db);
      db->autoCommit = 1;
    }else if( (rc = sqlite3VdbeCheckDeferred(p))!=SQLITE_OK ){
      goto vdbe_return;
    }else{
      db->autoCommit = (u8)desiredAutoCommit;
      if( sqlite3VdbeHalt(p)==SQLITE_BUSY ){
        p->pc = pc;
        db->autoCommit = (u8)(1-desiredAutoCommit);
        p->rc = rc = SQLITE_BUSY;
        goto vdbe_return;

      assert( sqlite3BtreeIsInTrans(pBt) );
      if( p->iStatement==0 ){
        assert( db->nStatement>=0 && db->nSavepoint>=0 );
        db->nStatement++; 
        p->iStatement = db->nSavepoint + db->nStatement;
      }
      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;
    }
  }
  break;
}

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

  SubProgram *pProgram;   /* Sub-program to execute */
  void *t;                /* Token identifying trigger */

  pProgram = pOp->p4.pProgram;
  pRt = &p->aMem[pOp->p3];
  assert( pProgram->nOp>0 );
  
  /* If the p5 flag is clear, then recursive invocation of triggers is 
  ** disabled for backwards compatibility (p5 is set if this sub-program
  ** is really a trigger, not a foreign key action, and the flag set
  ** and cleared by the "PRAGMA recursive_triggers" command is clear).
  ** 
  ** It is recursive invocation of triggers, at the SQL level, that is 
  ** disabled. In some cases a single trigger may generate more than one 
  ** SubProgram (if the trigger may be executed with more than one different 
  ** ON CONFLICT algorithm). SubProgram structures associated with a
  ** single trigger all have the same value for the SubProgram.token 
  ** variable.  */

  if( pOp->p5 ){
    t = pProgram->token;
    for(pFrame=p->pFrame; pFrame && pFrame->token!=t; pFrame=pFrame->pParent);
    if( pFrame ) break;
  }

  if( p->nFrame>db->aLimit[SQLITE_LIMIT_TRIGGER_DEPTH] ){
    rc = SQLITE_ERROR;

  pIn = &pFrame->aMem[pOp->p1 + pFrame->aOp[pFrame->pc].p1];   
  sqlite3VdbeMemShallowCopy(pOut, pIn, MEM_Ephem);
  break;
}

#endif /* #ifndef SQLITE_OMIT_TRIGGER */

#ifndef SQLITE_OMIT_FOREIGN_KEY
/* Opcode: DeferredCons P1 * * * *
**
** Increment the database handles "deferred constraint violation" counter
** by P1 (P1 may be negative or positive).
*/
case OP_DeferredCons: {
  db->nDeferredCons += pOp->p1;
  break;
}
#endif /* #ifndef SQLITE_OMIT_FOREIGN_KEY */

#ifndef SQLITE_OMIT_AUTOINCREMENT
/* Opcode: MemMax P1 P2 * * *
**
** P1 is a register in the root frame of this VM (the root frame is
** different from the current frame if this instruction is being executed
** within a sub-program). Set the value of register P1 to the maximum of 
** its current value and the value in register P2.

  int nChange;            /* Number of db changes made since last reset */
  int btreeMask;          /* Bitmask of db->aDb[] entries referenced */
  i64 startTime;          /* Time when query started - used for profiling */
  BtreeMutexArray aMutex; /* An array of Btree used here and needing locks */
  int aCounter[2];        /* Counters used by sqlite3_stmt_status() */
  char *zSql;             /* Text of the SQL statement that generated this */
  void *pFree;            /* Free this when deleting the vdbe */
  i64 nStmtDefCons;       /* Number of def. constraints when stmt started */
  int iStatement;         /* Statement number (or 0 if has not opened stmt) */
#ifdef SQLITE_DEBUG
  FILE *trace;            /* Write an execution trace here, if not NULL */
#endif
  VdbeFrame *pFrame;      /* Parent frame */
  int nFrame;             /* Number of frames in pFrame list */
};

int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve);
int sqlite3VdbeCloseStatement(Vdbe *, int);
void sqlite3VdbeFrameDelete(VdbeFrame*);
int sqlite3VdbeFrameRestore(VdbeFrame *);
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
int sqlite3VdbeReleaseBuffers(Vdbe *p);
#endif

#ifndef SQLITE_OMIT_FOREIGN_KEY
int sqlite3VdbeCheckDeferred(Vdbe *);
#else
# define sqlite3VdbeCheckDeferred(p) 0
#endif

#ifndef SQLITE_OMIT_SHARED_CACHE
void sqlite3VdbeMutexArrayEnter(Vdbe *p);
#else
# define sqlite3VdbeMutexArrayEnter(p)
#endif

    /* If there are no other statements currently running, then
    ** 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 );

#ifndef SQLITE_OMIT_TRACE
    if( db->xProfile && !db->init.busy ){
      double rNow;
      sqlite3OsCurrentTime(db->pVfs, &rNow);
      p->startTime = (u64)((rNow - (int)rNow)*3600.0*24.0*1000000000.0);
    }

        if( rc==SQLITE_OK ){
          rc = rc2;
        }
      }
    }
    db->nStatement--;
    p->iStatement = 0;

    /* 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;
    }
  }
  return rc;
}

/*
** If SQLite is compiled to support shared-cache mode and to be threadsafe,
** this routine obtains the mutex associated with each BtShared structure

  sqlite3BtreeMutexArrayEnter(&p->aMutex);
#else
  sqlite3BtreeEnterAll(p->db);
#endif
}
#endif

/*
** 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 and write
** an error message to it. Then return SQLITE_ERROR.
*/
#ifndef SQLITE_OMIT_FOREIGN_KEY
int sqlite3VdbeCheckDeferred(Vdbe *p){
  sqlite3 *db = p->db;
  if( db->nDeferredCons ){
    p->rc = SQLITE_CONSTRAINT;
    sqlite3SetString(&p->zErrMsg, db, "foreign key constraint failed");
    return SQLITE_ERROR;
  }
  return SQLITE_OK;
}
#endif

/*
** This routine is called the when a VDBE tries to halt.  If the VDBE
** has made changes and is in autocommit mode, then commit those
** changes.  If a rollback is needed, then do the rollback.
**
** This routine is the only way to move the state of a VM from
** SQLITE_MAGIC_RUN to SQLITE_MAGIC_HALT.  It is harmless to

    ** above has occurred. 
    */
    if( !sqlite3VtabInSync(db) 
     && db->autoCommit 
     && db->writeVdbeCnt==(p->readOnly==0) 
    ){
      if( p->rc==SQLITE_OK || (p->errorAction==OE_Fail && !isSpecialError) ){
        if( sqlite3VdbeCheckDeferred(p) ){
          sqlite3BtreeMutexArrayLeave(&p->aMutex);
          return SQLITE_ERROR;
        }
        /* The auto-commit flag is true, the vdbe program was successful 
        ** or hit an 'OR FAIL' constraint and there are no deferred foreign
        ** key constraints to hold up the transaction. This means a commit 
        ** is required.  */

        rc = vdbeCommit(db, p);
        if( rc==SQLITE_BUSY ){
          sqlite3BtreeMutexArrayLeave(&p->aMutex);
          return SQLITE_BUSY;
        }else if( rc!=SQLITE_OK ){
          p->rc = rc;
          sqlite3RollbackAll(db);
        }else{
          db->nDeferredCons = 0;
          sqlite3CommitInternalChanges(db);
        }
      }else{
        sqlite3RollbackAll(db);
      }
      db->nStatement = 0;
    }else if( eStatementOp==0 ){

      rc = SQLITE_ERROR;
      (void)sqlite3SafetyOff(db);
      sqlite3BtreeLeaveAll(db);
      goto blob_open_out;
    }

    /* If the value is being opened for writing, check that the
    ** column is not indexed, and that it is not part of a foreign key. 
    ** It is against the rules to open a column to which either of these
    ** descriptions applies for writing.  */

    if( flags ){
      const char *zFault = 0;
      Index *pIdx;
#ifndef SQLITE_OMIT_FOREIGN_KEY
      if( db->flags&SQLITE_ForeignKeys ){
        FKey *pFKey;
        for(pFKey=pTab->pFKey; pFKey; pFKey=pFKey->pNextFrom){
          int j;
          for(j=0; j<pFKey->nCol; j++){
            if( pFKey->aCol[j].iFrom==iCol ){
              zFault = "foreign key";
            }
          }
        }
      }
#endif
      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
        int j;
        for(j=0; j<pIdx->nColumn; j++){
          if( pIdx->aiColumn[j]==iCol ){


            zFault = "indexed";




          }
        }
      }
      if( zFault ){
        sqlite3DbFree(db, zErr);
        zErr = sqlite3MPrintf(db, "cannot open %s column for writing", zFault);
        rc = SQLITE_ERROR;
        (void)sqlite3SafetyOff(db);
        sqlite3BtreeLeaveAll(db);
        goto blob_open_out;
      }
    }

    v = sqlite3VdbeCreate(db);
    if( v ){
      int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
      sqlite3VdbeAddOpList(v, sizeof(openBlob)/sizeof(VdbeOpList), openBlob);
      flags = !!flags;                 /* flags = (flags ? 1 : 0); */

  set authargs {}
  execsql {
    UPDATE v1 SET x=1 WHERE x=117
  }
  set authargs
} [list \
  SQLITE_UPDATE v1     x  main {} \



  SQLITE_SELECT {}     {} {}   v1 \
  SQLITE_READ   t2     a  main v1 \
  SQLITE_READ   t2     b  main v1 \
  SQLITE_SELECT {}     {} {}   {} \
  SQLITE_READ   v1     x  main v1 \
  SQLITE_INSERT v1chng {} main r2 \
  SQLITE_READ   v1     x  main r2 \
  SQLITE_READ   v1     x  main r2 \
]

do_test auth-4.4 {
  execsql {
    CREATE TRIGGER r3 INSTEAD OF DELETE ON v1 BEGIN
      INSERT INTO v1chng VALUES(OLD.x,NULL);
    END;
    SELECT * FROM v1;
  }

      y TEXT
    );
  }
} {}
do_test fkey1-1.2 {
  execsql {
    CREATE TABLE t3(
      a INTEGER REFERENCES t2,
      b INTEGER REFERENCES t1,
      FOREIGN KEY (a,b) REFERENCES t2(x,y)
    );
  }
} {}

do_test fkey1-2.1 {

    CREATE TABLE t5(a PRIMARY KEY, b, c);
    CREATE TABLE t6(
      d REFERENCES t5,
      e REFERENCES t5(c)
    );
    PRAGMA foreign_key_list(t6);
  }
} [concat                                         \
  {0 0 t5 e c {NO ACTION} {NO ACTION} NONE}       \
  {1 0 t5 d {} {NO ACTION} {NO ACTION} NONE}      \
]
do_test fkey1-3.2 {
  execsql {
    CREATE TABLE t7(d, e, f,
      FOREIGN KEY (d, e) REFERENCES t5(a, b)
    );
    PRAGMA foreign_key_list(t7);
  }
} [concat                                   \
  {0 0 t5 d a {NO ACTION} {NO ACTION} NONE} \
  {0 1 t5 e b {NO ACTION} {NO ACTION} NONE} \
]
do_test fkey1-3.3 {
  execsql {
    CREATE TABLE t8(d, e, f,
      FOREIGN KEY (d, e) REFERENCES t5 ON DELETE CASCADE ON UPDATE SET NULL
    );
    PRAGMA foreign_key_list(t8);

# 2009 September 15
#
# 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 implements regression tests for SQLite library.
#
# This file implements tests for foreign keys.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

#-------------------------------------------------------------------------
# Test structure:
#
# fkey2-1.*: Simple tests to check that immediate and deferred foreign key 
#            constraints work when not inside a transaction.
#            
# fkey2-2.*: Tests to verify that deferred foreign keys work inside
#            explicit transactions (i.e that processing really is deferred).
#
# fkey2-3.*: Tests that a statement transaction is rolled back if an
#            immediate foreign key constraint is violated.
#
# fkey2-4.*: Test that FK actions may recurse even when recursive triggers
#            are disabled.
#
# fkey2-5.*: Check that if foreign-keys are enabled, it is not possible
#            to write to an FK column using the incremental blob API.
#
# fkey2-genfkey.*: Tests that were used with the shell tool .genfkey
#            command. Recycled to test the built-in implementation.
#


proc drop_all_tables {{db db}} {
  set tbls [execsql {SELECT name FROM sqlite_master WHERE type = 'table'}]
  foreach t [execsql {
    SELECT name FROM sqlite_master 
    WHERE type = 'table' AND name NOT like 'sqlite_%'
  }] {
    execsql "DROP TABLE $t"
  }
}


execsql { PRAGMA foreign_keys = on }

set FkeySimpleSchema {
  PRAGMA foreign_keys = on;
  CREATE TABLE t1(a PRIMARY KEY, b);
  CREATE TABLE t2(c REFERENCES t1(a) /D/ , d);

  CREATE TABLE t3(a PRIMARY KEY, b);
  CREATE TABLE t4(c REFERENCES t3 /D/, d);

  CREATE TABLE t5(a INTEGER PRIMARY KEY, b);
  CREATE TABLE t6(c REFERENCES t5(oid) /D/, d);

  CREATE TABLE t7(a, b INTEGER PRIMARY KEY);
  CREATE TABLE t8(c REFERENCES t7 /D/, d);

  CREATE TABLE t9(a REFERENCES nosuchtable, b);
  CREATE TABLE t10(a REFERENCES t9(c) /D/, b);
}
set FkeySimpleTests {
  1.1  "INSERT INTO t2 VALUES(1, 3)"      {1 {foreign key constraint failed}}
  1.2  "INSERT INTO t1 VALUES(1, 2)"      {0 {}}
  1.3  "INSERT INTO t2 VALUES(1, 3)"      {0 {}}
  1.4  "INSERT INTO t2 VALUES(2, 4)"      {1 {foreign key constraint failed}}
  1.5  "INSERT INTO t2 VALUES(NULL, 4)"   {0 {}}
  1.6  "UPDATE t2 SET c=2 WHERE d=4"      {1 {foreign key constraint failed}}
  1.7  "UPDATE t2 SET c=1 WHERE d=4"      {0 {}}
  1.9  "UPDATE t2 SET c=1 WHERE d=4"      {0 {}}
  1.10 "UPDATE t2 SET c=NULL WHERE d=4"   {0 {}}
  1.11 "DELETE FROM t1 WHERE a=1"         {1 {foreign key constraint failed}}
  1.12 "UPDATE t1 SET a = 2"              {1 {foreign key constraint failed}}
  1.13 "UPDATE t1 SET a = 1"              {0 {}}

  2.1  "INSERT INTO t4 VALUES(1, 3)"      {1 {foreign key constraint failed}}
  2.2  "INSERT INTO t3 VALUES(1, 2)"      {0 {}}
  2.3  "INSERT INTO t4 VALUES(1, 3)"      {0 {}}

  3.1  "INSERT INTO t6 VALUES(1, 3)"      {1 {foreign key constraint failed}}
  3.2  "INSERT INTO t5 VALUES(1, 2)"      {0 {}}
  3.3  "INSERT INTO t6 VALUES(1, 3)"      {0 {}}

  4.1  "INSERT INTO t8 VALUES(1, 3)"      {1 {foreign key constraint failed}}
  4.2  "INSERT INTO t7 VALUES(2, 1)"      {0 {}}
  4.3  "INSERT INTO t8 VALUES(1, 3)"      {0 {}}
  4.4  "INSERT INTO t8 VALUES(2, 4)"      {1 {foreign key constraint failed}}
  4.5  "INSERT INTO t8 VALUES(NULL, 4)"   {0 {}}
  4.6  "UPDATE t8 SET c=2 WHERE d=4"      {1 {foreign key constraint failed}}
  4.7  "UPDATE t8 SET c=1 WHERE d=4"      {0 {}}
  4.9  "UPDATE t8 SET c=1 WHERE d=4"      {0 {}}
  4.10 "UPDATE t8 SET c=NULL WHERE d=4"   {0 {}}
  4.11 "DELETE FROM t7 WHERE b=1"         {1 {foreign key constraint failed}}
  4.12 "UPDATE t7 SET b = 2"              {1 {foreign key constraint failed}}
  4.13 "UPDATE t7 SET b = 1"              {0 {}}

  5.1  "INSERT INTO t9 VALUES(1, 3)"      {1 {no such table: main.nosuchtable}}
  5.2  "INSERT INTO t10 VALUES(1, 3)"     {1 {foreign key mismatch}}
}

do_test fkey2-1.1.0 {
  execsql [string map {/D/ {}} $FkeySimpleSchema]
} {}
foreach {tn zSql res} $FkeySimpleTests {
  do_test fkey2-1.1.$tn { catchsql $zSql } $res
}
drop_all_tables

do_test fkey2-1.2.0 {
  execsql [string map {/D/ {DEFERRABLE INITIALLY DEFERRED}} $FkeySimpleSchema
  ]
} {}
foreach {tn zSql res} $FkeySimpleTests {
  do_test fkey2-1.2.$tn { catchsql $zSql } $res
}
drop_all_tables

#-------------------------------------------------------------------------
# This section (test cases fkey2-2.*) contains tests to check that the
# deferred foreign key constraint logic works.
#
proc fkey2-2-test {tn nocommit sql {res {}}} {
  if {$res eq "FKV"} {
    set expected {1 {foreign key constraint failed}}
  } else {
    set expected [list 0 $res]
  }
  do_test fkey2-2.$tn [list catchsql $sql] $expected
  if {$nocommit} {
    do_test fkey2-2.${tn}c {
      catchsql COMMIT
    } {1 {foreign key constraint failed}}
  }
}

fkey2-2-test 1 0 {
  CREATE TABLE node(
    nodeid PRIMARY KEY,
    parent REFERENCES node DEFERRABLE INITIALLY DEFERRED
  );
  CREATE TABLE leaf(
    cellid PRIMARY KEY,
    parent REFERENCES node DEFERRABLE INITIALLY DEFERRED
  );
}

fkey2-2-test 1  0 "INSERT INTO node VALUES(1, 0)"       FKV
fkey2-2-test 2  0 "BEGIN"
fkey2-2-test 3  1   "INSERT INTO node VALUES(1, 0)"
fkey2-2-test 4  0   "UPDATE node SET parent = NULL"
fkey2-2-test 5  0 "COMMIT"
fkey2-2-test 6  0 "SELECT * FROM node" {1 {}}

fkey2-2-test 7  0 "BEGIN"
fkey2-2-test 8  1   "INSERT INTO leaf VALUES('a', 2)"
fkey2-2-test 9  1   "INSERT INTO node VALUES(2, 0)"
fkey2-2-test 10 0   "UPDATE node SET parent = 1 WHERE nodeid = 2"
fkey2-2-test 11 0 "COMMIT"
fkey2-2-test 12 0 "SELECT * FROM node" {1 {} 2 1}
fkey2-2-test 13 0 "SELECT * FROM leaf" {a 2}

fkey2-2-test 14 0 "BEGIN"
fkey2-2-test 15 1   "DELETE FROM node WHERE nodeid = 2"
fkey2-2-test 16 0   "INSERT INTO node VALUES(2, NULL)"
fkey2-2-test 17 0 "COMMIT"
fkey2-2-test 18 0 "SELECT * FROM node" {1 {} 2 {}}
fkey2-2-test 19 0 "SELECT * FROM leaf" {a 2}

fkey2-2-test 20 0 "BEGIN"
fkey2-2-test 21 0   "INSERT INTO leaf VALUES('b', 1)"
fkey2-2-test 22 0   "SAVEPOINT save"
fkey2-2-test 23 0     "DELETE FROM node WHERE nodeid = 1"
fkey2-2-test 24 0   "ROLLBACK TO save"
fkey2-2-test 25 0 "COMMIT"
fkey2-2-test 26 0 "SELECT * FROM node" {1 {} 2 {}}
fkey2-2-test 27 0 "SELECT * FROM leaf" {a 2 b 1}

fkey2-2-test 28 0 "BEGIN"
fkey2-2-test 29 0   "INSERT INTO leaf VALUES('c', 1)"
fkey2-2-test 30 0   "SAVEPOINT save"
fkey2-2-test 31 0     "DELETE FROM node WHERE nodeid = 1"
fkey2-2-test 32 1   "RELEASE save"
fkey2-2-test 33 1   "DELETE FROM leaf WHERE cellid = 'b'"
fkey2-2-test 34 0   "DELETE FROM leaf WHERE cellid = 'c'"
fkey2-2-test 35 0 "COMMIT"
fkey2-2-test 36 0 "SELECT * FROM node" {2 {}} 
fkey2-2-test 37 0 "SELECT * FROM leaf" {a 2}

fkey2-2-test 38 0 "SAVEPOINT outer"
fkey2-2-test 39 1   "INSERT INTO leaf VALUES('d', 3)"
fkey2-2-test 40 1 "RELEASE outer"    FKV
fkey2-2-test 41 1   "INSERT INTO leaf VALUES('e', 3)"
fkey2-2-test 42 0   "INSERT INTO node VALUES(3, 2)"
fkey2-2-test 43 0 "RELEASE outer"

fkey2-2-test 44 0 "SAVEPOINT outer"
fkey2-2-test 45 1   "DELETE FROM node WHERE nodeid=3"
fkey2-2-test 47 0   "INSERT INTO node VALUES(3, 2)"
fkey2-2-test 48 0 "ROLLBACK TO outer"
fkey2-2-test 49 0 "RELEASE outer"

fkey2-2-test 50 0 "SAVEPOINT outer"
fkey2-2-test 51 1   "INSERT INTO leaf VALUES('f', 4)"
fkey2-2-test 52 1   "SAVEPOINT inner"
fkey2-2-test 53 1     "INSERT INTO leaf VALUES('g', 4)"
fkey2-2-test 54 1  "RELEASE outer"   FKV
fkey2-2-test 55 1   "ROLLBACK TO inner"
fkey2-2-test 56 0  "COMMIT"          FKV
fkey2-2-test 57 0   "INSERT INTO node VALUES(4, NULL)"
fkey2-2-test 58 0 "RELEASE outer"
fkey2-2-test 59 0 "SELECT * FROM node" {2 {} 3 2 4 {}}
fkey2-2-test 60 0 "SELECT * FROM leaf" {a 2 d 3 e 3 f 4}

# The following set of tests check that if a statement that affects 
# multiple rows violates some foreign key constraints, then strikes a 
# constraint that causes the statement-transaction to be rolled back, 
# the deferred constraint counter is correctly reset to the value it 
# had before the statement-transaction was opened.
#
fkey2-2-test 61 0 "BEGIN"
fkey2-2-test 62 0   "DELETE FROM leaf"
fkey2-2-test 63 0   "DELETE FROM node"
fkey2-2-test 64 1   "INSERT INTO leaf VALUES('a', 1)"
fkey2-2-test 65 1   "INSERT INTO leaf VALUES('b', 2)"
fkey2-2-test 66 1   "INSERT INTO leaf VALUES('c', 1)"
do_test fkey2-2-test-67 {
  catchsql          "INSERT INTO node SELECT parent, 3 FROM leaf"
} {1 {column nodeid is not unique}}
fkey2-2-test 68 0 "COMMIT"           FKV
fkey2-2-test 69 1   "INSERT INTO node VALUES(1, NULL)"
fkey2-2-test 70 0   "INSERT INTO node VALUES(2, NULL)"
fkey2-2-test 71 0 "COMMIT"

fkey2-2-test 72 0 "BEGIN"
fkey2-2-test 73 1   "DELETE FROM node"
fkey2-2-test 74 0   "INSERT INTO node(nodeid) SELECT DISTINCT parent FROM leaf"
fkey2-2-test 75 0 "COMMIT"

#-------------------------------------------------------------------------
# Test cases fkey2-3.* test that a program that executes foreign key
# actions (CASCADE, SET DEFAULT, SET NULL etc.) or tests FK constraints
# opens a statement transaction if required.
#
# fkey2-3.1.*: Test UPDATE statements.
# fkey2-3.2.*: Test DELETE statements.
#
drop_all_tables
do_test fkey2-3.1.1 {
  execsql {
    CREATE TABLE ab(a PRIMARY KEY, b);
    CREATE TABLE cd(
      c PRIMARY KEY REFERENCES ab ON UPDATE CASCADE ON DELETE CASCADE, 
      d
    );
    CREATE TABLE ef(
      e REFERENCES cd ON UPDATE CASCADE, 
      f, CHECK (e!=5)
    );
  }
} {}
do_test fkey2-3.1.2 {
  execsql {
    INSERT INTO ab VALUES(1, 'b');
    INSERT INTO cd VALUES(1, 'd');
    INSERT INTO ef VALUES(1, 'e');
  }
} {}
do_test fkey2-3.1.3 {
  catchsql { UPDATE ab SET a = 5 }
} {1 {constraint failed}}
do_test fkey2-3.1.4 {
  execsql { SELECT * FROM ab }
} {1 b}
do_test fkey2-3.1.4 {
  execsql BEGIN;
  catchsql { UPDATE ab SET a = 5 }
} {1 {constraint failed}}
do_test fkey2-3.1.5 {
  execsql COMMIT;
  execsql { SELECT * FROM ab; SELECT * FROM cd; SELECT * FROM ef }
} {1 b 1 d 1 e}
do_test fkey2-3.2.1 {
  execsql BEGIN;
  catchsql { DELETE FROM ab }
} {1 {foreign key constraint failed}}
do_test fkey2-3.2.2 {
  execsql COMMIT
  execsql { SELECT * FROM ab; SELECT * FROM cd; SELECT * FROM ef }
} {1 b 1 d 1 e}

#-------------------------------------------------------------------------
# Test cases fkey2-4.* test that recursive foreign key actions 
# (i.e. CASCADE) are allowed even if recursive triggers are disabled.
#
drop_all_tables
do_test fkey2-4.1 {
  execsql {
    CREATE TABLE t1(
      node PRIMARY KEY, 
      parent REFERENCES t1 ON DELETE CASCADE
    );
    CREATE TABLE t2(node PRIMARY KEY, parent);
    CREATE TRIGGER t2t AFTER DELETE ON t2 BEGIN
      DELETE FROM t2 WHERE parent = old.node;
    END;
    INSERT INTO t1 VALUES(1, NULL);
    INSERT INTO t1 VALUES(2, 1);
    INSERT INTO t1 VALUES(3, 1);
    INSERT INTO t1 VALUES(4, 2);
    INSERT INTO t1 VALUES(5, 2);
    INSERT INTO t1 VALUES(6, 3);
    INSERT INTO t1 VALUES(7, 3);
    INSERT INTO t2 SELECT * FROM t1;
  }
} {}
do_test fkey2-4.2 {
  execsql { PRAGMA recursive_triggers = off }
  execsql { 
    BEGIN;
      DELETE FROM t1 WHERE node = 1;
      SELECT node FROM t1;
  }
} {}
do_test fkey2-4.3 {
  execsql { 
      DELETE FROM t2 WHERE node = 1;
      SELECT node FROM t2;
    ROLLBACK;
  }
} {4 5 6 7}
do_test fkey2-4.4 {
  execsql { PRAGMA recursive_triggers = on }
  execsql { 
    BEGIN;
      DELETE FROM t1 WHERE node = 1;
      SELECT node FROM t1;
  }
} {}
do_test fkey2-4.3 {
  execsql { 
      DELETE FROM t2 WHERE node = 1;
      SELECT node FROM t2;
    ROLLBACK;
  }
} {}

#-------------------------------------------------------------------------
# Test cases fkey2-5.* verify that the incremental blob API may not
# write to a foreign key column while foreign-keys are enabled.
#
drop_all_tables
do_test fkey2-5.1 {
  execsql {
    CREATE TABLE t1(a PRIMARY KEY, b);
    CREATE TABLE t2(a PRIMARY KEY, b REFERENCES t1(a));
    INSERT INTO t1 VALUES('hello', 'world');
    INSERT INTO t2 VALUES('key', 'hello');
  }
} {}
do_test fkey2-5.2 {
  set rc [catch { set fd [db incrblob t2 b 1] } msg]
  list $rc $msg
} {1 {cannot open foreign key column for writing}}
do_test fkey2-5.3 {
  set rc [catch { set fd [db incrblob -readonly t2 b 1] } msg]
  close $fd
  set rc
} {0}
do_test fkey2-5.4 {
  execsql { PRAGMA foreign_keys = off }
  set rc [catch { set fd [db incrblob t2 b 1] } msg]
  close $fd
  set rc
} {0}
do_test fkey2-5.5 {
  execsql { PRAGMA foreign_keys = on }
} {}

#-------------------------------------------------------------------------
# The following block of tests, those prefixed with "fkey2-genfkey.", are 
# the same tests that were used to test the ".genfkey" command provided 
# by the shell tool. So these tests show that the built-in foreign key 
# implementation is more or less compatible with the triggers generated 
# by genfkey.
#
drop_all_tables
do_test fkey2-genfkey.1.1 {
  execsql {
    CREATE TABLE t1(a INTEGER PRIMARY KEY, b, c, UNIQUE(b, c));
    CREATE TABLE t2(e REFERENCES t1, f);
    CREATE TABLE t3(g, h, i, FOREIGN KEY (h, i) REFERENCES t1(b, c));
  }
} {}
do_test fkey2-genfkey.1.2 {
  catchsql { INSERT INTO t2 VALUES(1, 2) }
} {1 {foreign key constraint failed}}
do_test fkey2-genfkey.1.3 {
  execsql {
    INSERT INTO t1 VALUES(1, 2, 3);
    INSERT INTO t2 VALUES(1, 2);
  }
} {}
do_test fkey2-genfkey.1.4 {
  execsql { INSERT INTO t2 VALUES(NULL, 3) }
} {}
do_test fkey2-genfkey.1.5 {
  catchsql { UPDATE t2 SET e = 5 WHERE e IS NULL }
} {1 {foreign key constraint failed}}
do_test fkey2-genfkey.1.6 {
  execsql { UPDATE t2 SET e = 1 WHERE e IS NULL }
} {}
do_test fkey2-genfkey.1.7 {
  execsql { UPDATE t2 SET e = NULL WHERE f = 3 }
} {}
do_test fkey2-genfkey.1.8 {
  catchsql { UPDATE t1 SET a = 10 }
} {1 {foreign key constraint failed}}
do_test fkey2-genfkey.1.9 {
  catchsql { UPDATE t1 SET a = NULL }
} {1 {datatype mismatch}}
do_test fkey2-genfkey.1.10 {
  catchsql { DELETE FROM t1 }
} {1 {foreign key constraint failed}}
do_test fkey2-genfkey.1.11 {
  execsql { UPDATE t2 SET e = NULL }
} {}
do_test fkey2-genfkey.1.12 {
  execsql { 
    UPDATE t1 SET a = 10;
    DELETE FROM t1;
    DELETE FROM t2;
  }
} {}
do_test fkey2-genfkey.1.13 {
  execsql {
    INSERT INTO t3 VALUES(1, NULL, NULL);
    INSERT INTO t3 VALUES(1, 2, NULL);
    INSERT INTO t3 VALUES(1, NULL, 3);
  }
} {}
do_test fkey2-genfkey.1.14 {
  catchsql { INSERT INTO t3 VALUES(3, 1, 4) }
} {1 {foreign key constraint failed}}
do_test fkey2-genfkey.1.15 {
  execsql { 
    INSERT INTO t1 VALUES(1, 1, 4);
    INSERT INTO t3 VALUES(3, 1, 4);
  }
} {}
do_test fkey2-genfkey.1.16 {
  catchsql { DELETE FROM t1 }
} {1 {foreign key constraint failed}}
do_test fkey2-genfkey.1.17 {
  catchsql { UPDATE t1 SET b = 10}
} {1 {foreign key constraint failed}}
do_test fkey2-genfkey.1.18 {
  execsql { UPDATE t1 SET a = 10}
} {}
do_test fkey2-genfkey.1.19 {
  catchsql { UPDATE t3 SET h = 'hello' WHERE i = 3}
} {1 {foreign key constraint failed}}

drop_all_tables
do_test fkey2-genfkey.2.1 {
  execsql {
    CREATE TABLE t1(a INTEGER PRIMARY KEY, b, c, UNIQUE(b, c));
    CREATE TABLE t2(e REFERENCES t1 ON UPDATE CASCADE ON DELETE CASCADE, f);
    CREATE TABLE t3(g, h, i, 
        FOREIGN KEY (h, i) 
        REFERENCES t1(b, c) ON UPDATE CASCADE ON DELETE CASCADE
    );
  }
} {}
do_test fkey2-genfkey.2.2 {
  execsql {
    INSERT INTO t1 VALUES(1, 2, 3);
    INSERT INTO t1 VALUES(4, 5, 6);
    INSERT INTO t2 VALUES(1, 'one');
    INSERT INTO t2 VALUES(4, 'four');
  }
} {}
do_test fkey2-genfkey.2.3 {
  execsql {
    UPDATE t1 SET a = 2 WHERE a = 1;
    SELECT * FROM t2;
  }
} {2 one 4 four}
do_test fkey2-genfkey.2.4 {
  execsql {
    DELETE FROM t1 WHERE a = 4;
    SELECT * FROM t2;
  }
} {2 one}
do_test fkey2-genfkey.2.5 {
  execsql {
    INSERT INTO t3 VALUES('hello', 2, 3);
    UPDATE t1 SET c = 2;
    SELECT * FROM t3;
  }
} {hello 2 2}
do_test fkey2-genfkey.2.6 {
  execsql {
    DELETE FROM t1;
    SELECT * FROM t3;
  }
} {}

drop_all_tables
do_test fkey2-genfkey.3.1 {
  execsql {
    CREATE TABLE t1(a INTEGER PRIMARY KEY, b, c, UNIQUE(c, b));
    CREATE TABLE t2(e REFERENCES t1 ON UPDATE SET NULL ON DELETE SET NULL, f);
    CREATE TABLE t3(g, h, i, 
        FOREIGN KEY (h, i) 
        REFERENCES t1(b, c) ON UPDATE SET NULL ON DELETE SET NULL
    );
  }
} {}
do_test fkey2-genfkey.3.2 {
  execsql {
    INSERT INTO t1 VALUES(1, 2, 3);
    INSERT INTO t1 VALUES(4, 5, 6);
    INSERT INTO t2 VALUES(1, 'one');
    INSERT INTO t2 VALUES(4, 'four');
  }
} {}
do_test fkey2-genfkey.3.3 {
  execsql {
    UPDATE t1 SET a = 2 WHERE a = 1;
    SELECT * FROM t2;
  }
} {{} one 4 four}
do_test fkey2-genfkey.3.4 {
  execsql {
    DELETE FROM t1 WHERE a = 4;
    SELECT * FROM t2;
  }
} {{} one {} four}
do_test fkey2-genfkey.3.5 {
  execsql {
    INSERT INTO t3 VALUES('hello', 2, 3);
    UPDATE t1 SET c = 2;
    SELECT * FROM t3;
  }
} {hello {} {}}
do_test fkey2-genfkey.3.6 {
  execsql {
    UPDATE t3 SET h = 2, i = 2;
    DELETE FROM t1;
    SELECT * FROM t3;
  }
} {hello {} {}}

finish_test

db nullvalue {}
ifcapable {foreignkey} {
  do_test pragma-6.3.1 {
    execsql {
      CREATE TABLE t3(a int references t2(b), b UNIQUE);
      pragma foreign_key_list(t3);
    }
  } {0 0 t2 a b {NO ACTION} {NO ACTION} NONE}
  do_test pragma-6.3.2 {
    execsql {
      pragma foreign_key_list;
    }
  } {}
  do_test pragma-6.3.3 {
    execsql {

catchsql { pragma recursive_triggers = off } 

# Test that we can cause ROLLBACK, FAIL and ABORT correctly
#
catchsql { CREATE TABLE tbl(a, b ,c) }
execsql {
    CREATE TRIGGER before_tbl_insert BEFORE INSERT ON tbl BEGIN SELECT CASE 
        WHEN (new.a = 4) THEN RAISE(IGNORE) END;
    END;

    CREATE TRIGGER after_tbl_insert AFTER INSERT ON tbl BEGIN SELECT CASE 
        WHEN (new.a = 1) THEN RAISE(ABORT,    'Trigger abort') 
        WHEN (new.a = 2) THEN RAISE(FAIL,     'Trigger fail') 
        WHEN (new.a = 3) THEN RAISE(ROLLBACK, 'Trigger rollback') END;
    END;
}
# ABORT
do_test trigger3-1.1 {
    catchsql {
        BEGIN;
        INSERT INTO tbl VALUES (5, 5, 6);
        INSERT INTO tbl VALUES (1, 5, 6);
    }
} {1 {Trigger abort}}
do_test trigger3-1.2 {
    execsql {
        SELECT * FROM tbl;
        ROLLBACK;
    }
} {5 5 6}
do_test trigger3-1.3 {
    execsql {SELECT * FROM tbl}
} {}

# FAIL
do_test trigger3-2.1 {
    catchsql {
        BEGIN;
        INSERT INTO tbl VALUES (5, 5, 6);
        INSERT INTO tbl VALUES (2, 5, 6);
    }
} {1 {Trigger fail}}
do_test trigger3-2.2 {
    execsql {
        SELECT * FROM tbl;
        ROLLBACK;
    }
} {5 5 6 2 5 6}
# ROLLBACK
do_test trigger3-3.1 {
    catchsql {
        BEGIN;
        INSERT INTO tbl VALUES (5, 5, 6);
        INSERT INTO tbl VALUES (3, 5, 6);
    }
} {1 {Trigger rollback}}
do_test trigger3-3.2 {
    execsql {
        SELECT * FROM tbl;
    }
} {}

# Verify that a ROLLBACK trigger works like a FAIL trigger if
# we are not within a transaction.  Ticket #3035.
#
do_test trigger3-3.3 {
    catchsql {COMMIT}
    catchsql {
        INSERT INTO tbl VALUES (3, 9, 10);
    }
} {1 {Trigger rollback}}
do_test trigger3-3.4 {
    execsql {SELECT * FROM tbl}
} {}

# IGNORE
do_test trigger3-4.1 {
    catchsql {
        BEGIN;
        INSERT INTO tbl VALUES (5, 5, 6);
        INSERT INTO tbl VALUES (4, 5, 6);
    }
} {0 {}}
do_test trigger3-4.2 {
    execsql {
        SELECT * FROM tbl;
        ROLLBACK;
    }
} {5 5 6}

# Check that we can also do RAISE(IGNORE) for UPDATE and DELETE
execsql {DROP TABLE tbl;}
execsql {CREATE TABLE tbl (a, b, c);}
execsql {INSERT INTO tbl VALUES(1, 2, 3);}
execsql {INSERT INTO tbl VALUES(4, 5, 6);}
execsql {
    CREATE TRIGGER before_tbl_update BEFORE UPDATE ON tbl BEGIN
        SELECT CASE WHEN (old.a = 1) THEN RAISE(IGNORE) END;
    END;

    CREATE TRIGGER before_tbl_delete BEFORE DELETE ON tbl BEGIN
        SELECT CASE WHEN (old.a = 1) THEN RAISE(IGNORE) END;
    END;
}
do_test trigger3-5.1 {
    execsql {
        UPDATE tbl SET c = 10;
        SELECT * FROM tbl;
    }
} {1 2 3 4 5 10}
do_test trigger3-5.2 {
    execsql {
        DELETE FROM tbl;
        SELECT * FROM tbl;
    }
} {1 2 3}

# Check that RAISE(IGNORE) works correctly for nested triggers:
execsql {CREATE TABLE tbl2(a, b, c)}
execsql {
    CREATE TRIGGER after_tbl2_insert AFTER INSERT ON tbl2 BEGIN
        UPDATE tbl SET c = 10;
        INSERT INTO tbl2 VALUES (new.a, new.b, new.c);
    END;
}
do_test trigger3-6 {
    execsql {
        INSERT INTO tbl2 VALUES (1, 2, 3);
        SELECT * FROM tbl2;
        SELECT * FROM tbl;
    }
} {1 2 3 1 2 3 1 2 3}

# Check that things also work for view-triggers

ifcapable view {

execsql {CREATE VIEW tbl_view AS SELECT * FROM tbl}
execsql {
    CREATE TRIGGER tbl_view_insert INSTEAD OF INSERT ON tbl_view BEGIN
        SELECT CASE WHEN (new.a = 1) THEN RAISE(ROLLBACK, 'View rollback')
                    WHEN (new.a = 2) THEN RAISE(IGNORE) 
                    WHEN (new.a = 3) THEN RAISE(ABORT, 'View abort') END;
    END;
}

do_test trigger3-7.1 {
    catchsql {
        INSERT INTO tbl_view VALUES(1, 2, 3);
    }
} {1 {View rollback}}
do_test trigger3-7.2 {
    catchsql {
        INSERT INTO tbl_view VALUES(2, 2, 3);
    }
} {0 {}}
do_test trigger3-7.3 {
    catchsql {
        INSERT INTO tbl_view VALUES(3, 2, 3);
    }
} {1 {View abort}}

} ;# ifcapable view

integrity_check trigger3-8.1

catchsql { DROP TABLE tbl; } 
catchsql { DROP TABLE tbl2; } 
catchsql { DROP VIEW tbl_view; }

finish_test