[sqlite] Remove obsolete reference version 3.8.7.4.

third_party/sqlite/sqlite-src-3080704/src/fkey.c

Index: third_party/sqlite/sqlite-src-3080704/src/fkey.c
diff --git a/third_party/sqlite/sqlite-src-3080704/src/fkey.c b/third_party/sqlite/sqlite-src-3080704/src/fkey.c
deleted file mode 100644
index e816bd95daf30bcfa985eb89785c1e0c95d37a7a..0000000000000000000000000000000000000000
--- a/third_party/sqlite/sqlite-src-3080704/src/fkey.c
+++ /dev/null
@@ -1,1362 +0,0 @@
-/*
-**
-** 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
-#ifndef SQLITE_OMIT_TRIGGER
-
-/*
-** Deferred and Immediate FKs
-** --------------------------
-**
-** Foreign keys in SQLite come in two flavours: deferred and immediate.
-** If an immediate foreign key constraint is violated,
-** SQLITE_CONSTRAINT_FOREIGNKEY is returned 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 child table, search
-**        the parent table for a match. If none is found increment the
-**        constraint counter.
-**
-**   I.2) For each FK for which the table is the parent table, 
-**        search the child table for rows that correspond to the new
-**        row in the parent table. Decrement the counter for each row
-**        found (as the constraint is now satisfied).
-**
-** DELETE operations:
-**
-**   D.1) For each FK for which the table is the child table, 
-**        search the parent table for a row that corresponds to the 
-**        deleted row in the child table. If such a row is not found, 
-**        decrement the counter.
-**
-**   D.2) For each FK for which the table is the parent table, search 
-**        the child table for rows that correspond to the deleted row 
-**        in the parent table. For each found increment the counter.
-**
-** 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.
-**
-** Immediate constraints are usually handled similarly. The only difference 
-** is that the counter used is stored as part of each individual statement
-** object (struct Vdbe). If, after the statement has run, its immediate
-** constraint counter is greater than zero,
-** it returns SQLITE_CONSTRAINT_FOREIGNKEY
-** and the statement transaction is rolled back. An exception is an INSERT
-** statement that inserts a single row only (no triggers). In this case,
-** instead of using a counter, an exception is thrown immediately if the
-** INSERT violates a foreign key constraint. This is necessary as such
-** an INSERT does not open a statement transaction.
-**
-** 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. The functions used by the UPDATE/DELETE
-** generation code to query for this information are:
-**
-**   sqlite3FkRequired() - Test to see if FK processing is required.
-**   sqlite3FkOldmask()  - Query for the set of required old.* columns.
-**
-**
-** Externally accessible module functions
-** --------------------------------------
-**
-**   sqlite3FkCheck()    - Check for foreign key violations.
-**   sqlite3FkActions()  - Code triggers for ON UPDATE/ON DELETE actions.
-**   sqlite3FkDelete()   - Delete an FKey structure.
-*/
-
-/*
-** 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)
-*/
-
-/*
-** A foreign key constraint requires that the key columns in the parent
-** table are collectively subject to a UNIQUE or PRIMARY KEY constraint.
-** Given that pParent is the parent table for foreign key constraint pFKey, 
-** search the schema for a unique index on the parent key columns. 
-**
-** If successful, zero is returned. If the parent key is an INTEGER PRIMARY 
-** KEY column, then output variable *ppIdx is set to NULL. Otherwise, *ppIdx 
-** is set to point to the unique index. 
-** 
-** If the parent key consists of a single column (the foreign key constraint
-** is not a composite foreign key), output variable *paiCol is set to NULL.
-** Otherwise, it is set to point to an allocated array of size N, where
-** N is the number of columns in the parent key. The first element of the
-** array is the index of the child table column that is mapped by the FK
-** constraint to the parent table column stored in the left-most column
-** of index *ppIdx. The second element of the array is the index of the
-** child table column that corresponds to the second left-most column of
-** *ppIdx, and so on.
-**
-** If the required index cannot be found, either because:
-**
-**   1) The named parent key columns do not exist, or
-**
-**   2) The named parent key columns do exist, but are not subject to a
-**      UNIQUE or PRIMARY KEY constraint, or
-**
-**   3) No parent key columns were provided explicitly as part of the
-**      foreign key definition, and the parent table does not have a
-**      PRIMARY KEY, or
-**
-**   4) No parent key columns were provided explicitly as part of the
-**      foreign key definition, and the PRIMARY KEY of the parent table 
-**      consists of a different number of columns to the child key in 
-**      the child table.
-**
-** then non-zero is returned, and a "foreign key mismatch" error loaded
-** into pParse. If an OOM error occurs, non-zero is returned and the
-** pParse->db->mallocFailed flag is set.
-*/
-int sqlite3FkLocateIndex(
-  Parse *pParse,                  /* Parse context to store any error in */
-  Table *pParent,                 /* Parent table of FK constraint pFKey */
-  FKey *pFKey,                    /* Foreign key to find index for */
-  Index **ppIdx,                  /* OUT: Unique index on parent table */
-  int **paiCol                    /* OUT: Map of index columns in pFKey */
-){
-  Index *pIdx = 0;                    /* Value to return via *ppIdx */
-  int *aiCol = 0;                     /* Value to return via *paiCol */
-  int nCol = pFKey->nCol;             /* Number of columns in parent key */
-  char *zKey = pFKey->aCol[0].zCol;   /* Name of left-most parent key column */
-
-  /* The caller is responsible for zeroing output parameters. */
-  assert( ppIdx && *ppIdx==0 );
-  assert( !paiCol || *paiCol==0 );
-  assert( pParse );
-
-  /* If this is a non-composite (single column) foreign key, check if it 
-  ** maps to the INTEGER PRIMARY KEY of table pParent. 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) There is an INTEGER PRIMARY KEY column and the FK is implicitly 
-    **      mapped to the primary key of table pParent, or
-    **   2) The FK is explicitly mapped to a column declared as INTEGER
-    **      PRIMARY KEY.
-    */
-    if( pParent->iPKey>=0 ){
-      if( !zKey ) return 0;
-      if( !sqlite3StrICmp(pParent->aCol[pParent->iPKey].zName, zKey) ) return 0;
-    }
-  }else if( paiCol ){
-    assert( nCol>1 );
-    aiCol = (int *)sqlite3DbMallocRaw(pParse->db, nCol*sizeof(int));
-    if( !aiCol ) return 1;
-    *paiCol = aiCol;
-  }
-
-  for(pIdx=pParent->pIndex; pIdx; pIdx=pIdx->pNext){
-    if( pIdx->nKeyCol==nCol && IsUniqueIndex(pIdx) ){ 
-      /* 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( zKey==0 ){
-        /* If zKey is NULL, then this foreign key is implicitly mapped to 
-        ** the PRIMARY KEY of table pParent. The PRIMARY KEY index may be 
-        ** identified by the test.  */
-        if( IsPrimaryKeyIndex(pIdx) ){
-          if( aiCol ){
-            int i;
-            for(i=0; i<nCol; i++) aiCol[i] = pFKey->aCol[i].iFrom;
-          }
-          break;
-        }
-      }else{
-        /* If zKey is non-NULL, then this foreign key was declared to
-        ** map to an explicit list of columns in table pParent. Check if this
-        ** index matches those columns. Also, check that the index uses
-        ** the default collation sequences for each column. */
-        int i, j;
-        for(i=0; i<nCol; i++){
-          i16 iCol = pIdx->aiColumn[i];     /* Index of column in parent tbl */
-          char *zDfltColl;                  /* Def. collation for column */
-          char *zIdxCol;                    /* Name of indexed column */
-
-          /* If the index uses a collation sequence that is different from
-          ** the default collation sequence for the column, this index is
-          ** unusable. Bail out early in this case.  */
-          zDfltColl = pParent->aCol[iCol].zColl;
-          if( !zDfltColl ){
-            zDfltColl = "BINARY";
-          }
-          if( sqlite3StrICmp(pIdx->azColl[i], zDfltColl) ) break;
-
-          zIdxCol = pParent->aCol[iCol].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( !pIdx ){
-    if( !pParse->disableTriggers ){
-      sqlite3ErrorMsg(pParse,
-           "foreign key mismatch - \"%w\" referencing \"%w\"",
-           pFKey->pFrom->zName, pFKey->zTo);
-    }
-    sqlite3DbFree(pParse->db, aiCol);
-    return 1;
-  }
-
-  *ppIdx = pIdx;
-  return 0;
-}
-
-/*
-** This function is called when a row is inserted into or deleted from the 
-** child table of foreign key constraint pFKey. If an SQL UPDATE is executed 
-** on the child table of pFKey, this function is invoked twice for each row
-** affected - once to "delete" the old row, and then again to "insert" the
-** new row.
-**
-** Each time it is called, this function generates VDBE code to locate the
-** row in the parent table that corresponds to the row being inserted into 
-** or deleted from the child table. If the parent row can be found, no 
-** special action is taken. Otherwise, if the parent row can *not* be
-** found in the parent table:
-**
-**   Operation | FK type   | Action taken
-**   --------------------------------------------------------------------------
-**   INSERT      immediate   Increment the "immediate constraint counter".
-**
-**   DELETE      immediate   Decrement the "immediate constraint counter".
-**
-**   INSERT      deferred    Increment the "deferred constraint counter".
-**
-**   DELETE      deferred    Decrement the "deferred constraint counter".
-**
-** These operations are identified in the comment at the top of this file 
-** (fkey.c) as "I.1" and "D.1".
-*/
-static void fkLookupParent(
-  Parse *pParse,        /* Parse context */
-  int iDb,              /* Index of database housing pTab */
-  Table *pTab,          /* Parent table of FK pFKey */
-  Index *pIdx,          /* Unique index on parent key columns in pTab */
-  FKey *pFKey,          /* Foreign key constraint */
-  int *aiCol,           /* Map from parent key columns to child table columns */
-  int regData,          /* Address of array containing child table row */
-  int nIncr,            /* Increment constraint counter by this */
-  int isIgnore          /* If true, pretend pTab contains all NULL values */
-){
-  int i;                                    /* Iterator variable */
-  Vdbe *v = sqlite3GetVdbe(pParse);         /* Vdbe to add code to */
-  int iCur = pParse->nTab - 1;              /* Cursor number to use */
-  int iOk = sqlite3VdbeMakeLabel(v);        /* jump here if parent key found */
-
-  /* If nIncr is less than zero, then check at runtime if there are any
-  ** outstanding constraints to resolve. If there are not, there is no need
-  ** to check if deleting this row resolves any outstanding violations.
-  **
-  ** Check if any of the key columns in the child table row are NULL. If 
-  ** any are, then the constraint is considered satisfied. No need to 
-  ** search for a matching row in the parent table.  */
-  if( nIncr<0 ){
-    sqlite3VdbeAddOp2(v, OP_FkIfZero, pFKey->isDeferred, iOk);
-    VdbeCoverage(v);
-  }
-  for(i=0; i<pFKey->nCol; i++){
-    int iReg = aiCol[i] + regData + 1;
-    sqlite3VdbeAddOp2(v, OP_IsNull, iReg, iOk); VdbeCoverage(v);
-  }
-
-  if( isIgnore==0 ){
-    if( pIdx==0 ){
-      /* If pIdx is NULL, then the parent key is the INTEGER PRIMARY KEY
-      ** column of the parent table (table pTab).  */
-      int iMustBeInt;               /* Address of MustBeInt instruction */
-      int regTemp = sqlite3GetTempReg(pParse);
-  
-      /* Invoke MustBeInt to coerce the child key value to an integer (i.e. 
-      ** apply the affinity of the parent key). If this fails, then there
-      ** is no matching parent key. Before using MustBeInt, make a copy of
-      ** the value. Otherwise, the value inserted into the child key column
-      ** will have INTEGER affinity applied to it, which may not be correct.  */
-      sqlite3VdbeAddOp2(v, OP_SCopy, aiCol[0]+1+regData, regTemp);
-      iMustBeInt = sqlite3VdbeAddOp2(v, OP_MustBeInt, regTemp, 0);
-      VdbeCoverage(v);
-  
-      /* If the parent table is the same as the child table, and we are about
-      ** to increment the constraint-counter (i.e. this is an INSERT operation),
-      ** then check if the row being inserted matches itself. If so, do not
-      ** increment the constraint-counter.  */
-      if( pTab==pFKey->pFrom && nIncr==1 ){
-        sqlite3VdbeAddOp3(v, OP_Eq, regData, iOk, regTemp); VdbeCoverage(v);
-        sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
-      }
-  
-      sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenRead);
-      sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, regTemp); VdbeCoverage(v);
-      sqlite3VdbeAddOp2(v, OP_Goto, 0, iOk);
-      sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-2);
-      sqlite3VdbeJumpHere(v, iMustBeInt);
-      sqlite3ReleaseTempReg(pParse, regTemp);
-    }else{
-      int nCol = pFKey->nCol;
-      int regTemp = sqlite3GetTempRange(pParse, nCol);
-      int regRec = sqlite3GetTempReg(pParse);
-  
-      sqlite3VdbeAddOp3(v, OP_OpenRead, iCur, pIdx->tnum, iDb);
-      sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
-      for(i=0; i<nCol; i++){
-        sqlite3VdbeAddOp2(v, OP_Copy, aiCol[i]+1+regData, regTemp+i);
-      }
-  
-      /* If the parent table is the same as the child table, and we are about
-      ** to increment the constraint-counter (i.e. this is an INSERT operation),
-      ** then check if the row being inserted matches itself. If so, do not
-      ** increment the constraint-counter. 
-      **
-      ** If any of the parent-key values are NULL, then the row cannot match 
-      ** itself. So set JUMPIFNULL to make sure we do the OP_Found if any
-      ** of the parent-key values are NULL (at this point it is known that
-      ** none of the child key values are).
-      */
-      if( pTab==pFKey->pFrom && nIncr==1 ){
-        int iJump = sqlite3VdbeCurrentAddr(v) + nCol + 1;
-        for(i=0; i<nCol; i++){
-          int iChild = aiCol[i]+1+regData;
-          int iParent = pIdx->aiColumn[i]+1+regData;
-          assert( aiCol[i]!=pTab->iPKey );
-          if( pIdx->aiColumn[i]==pTab->iPKey ){
-            /* The parent key is a composite key that includes the IPK column */
-            iParent = regData;
-          }
-          sqlite3VdbeAddOp3(v, OP_Ne, iChild, iJump, iParent); VdbeCoverage(v);
-          sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);
-        }
-        sqlite3VdbeAddOp2(v, OP_Goto, 0, iOk);
-      }
-  
-      sqlite3VdbeAddOp4(v, OP_MakeRecord, regTemp, nCol, regRec,
-                        sqlite3IndexAffinityStr(v,pIdx), nCol);
-      sqlite3VdbeAddOp4Int(v, OP_Found, iCur, iOk, regRec, 0); VdbeCoverage(v);
-  
-      sqlite3ReleaseTempReg(pParse, regRec);
-      sqlite3ReleaseTempRange(pParse, regTemp, nCol);
-    }
-  }
-
-  if( !pFKey->isDeferred && !(pParse->db->flags & SQLITE_DeferFKs)
-   && !pParse->pToplevel 
-   && !pParse->isMultiWrite 
-  ){
-    /* Special case: If this is an INSERT statement that will insert exactly
-    ** one row into the table, raise a constraint immediately instead of
-    ** incrementing a counter. This is necessary as the VM code is being
-    ** generated for will not open a statement transaction.  */
-    assert( nIncr==1 );
-    sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_FOREIGNKEY,
-        OE_Abort, 0, P4_STATIC, P5_ConstraintFK);
-  }else{
-    if( nIncr>0 && pFKey->isDeferred==0 ){
-      sqlite3ParseToplevel(pParse)->mayAbort = 1;
-    }
-    sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, nIncr);
-  }
-
-  sqlite3VdbeResolveLabel(v, iOk);
-  sqlite3VdbeAddOp1(v, OP_Close, iCur);
-}
-
-
-/*
-** Return an Expr object that refers to a memory register corresponding
-** to column iCol of table pTab.
-**
-** regBase is the first of an array of register that contains the data
-** for pTab.  regBase itself holds the rowid.  regBase+1 holds the first
-** column.  regBase+2 holds the second column, and so forth.
-*/
-static Expr *exprTableRegister(
-  Parse *pParse,     /* Parsing and code generating context */
-  Table *pTab,       /* The table whose content is at r[regBase]... */
-  int regBase,       /* Contents of table pTab */
-  i16 iCol           /* Which column of pTab is desired */
-){
-  Expr *pExpr;
-  Column *pCol;
-  const char *zColl;
-  sqlite3 *db = pParse->db;
-
-  pExpr = sqlite3Expr(db, TK_REGISTER, 0);
-  if( pExpr ){
-    if( iCol>=0 && iCol!=pTab->iPKey ){
-      pCol = &pTab->aCol[iCol];
-      pExpr->iTable = regBase + iCol + 1;
-      pExpr->affinity = pCol->affinity;
-      zColl = pCol->zColl;
-      if( zColl==0 ) zColl = db->pDfltColl->zName;
-      pExpr = sqlite3ExprAddCollateString(pParse, pExpr, zColl);
-    }else{
-      pExpr->iTable = regBase;
-      pExpr->affinity = SQLITE_AFF_INTEGER;
-    }
-  }
-  return pExpr;
-}
-
-/*
-** Return an Expr object that refers to column iCol of table pTab which
-** has cursor iCur.
-*/
-static Expr *exprTableColumn(
-  sqlite3 *db,      /* The database connection */
-  Table *pTab,      /* The table whose column is desired */
-  int iCursor,      /* The open cursor on the table */
-  i16 iCol          /* The column that is wanted */
-){
-  Expr *pExpr = sqlite3Expr(db, TK_COLUMN, 0);
-  if( pExpr ){
-    pExpr->pTab = pTab;
-    pExpr->iTable = iCursor;
-    pExpr->iColumn = iCol;
-  }
-  return pExpr;
-}
-
-/*
-** This function is called to generate code executed when a row is deleted
-** from the parent table of foreign key constraint pFKey and, if pFKey is 
-** deferred, when a row is inserted into the same table. When generating
-** code for an SQL UPDATE operation, this function may be called twice -
-** once to "delete" the old row and once to "insert" the new row.
-**
-** The code generated by this function scans through the rows in the child
-** table that correspond to the parent table row being deleted or inserted.
-** For each child row found, one of the following actions is taken:
-**
-**   Operation | FK type   | Action taken
-**   --------------------------------------------------------------------------
-**   DELETE      immediate   Increment the "immediate constraint counter".
-**                           Or, if the ON (UPDATE|DELETE) action is RESTRICT,
-**                           throw a "FOREIGN KEY constraint failed" exception.
-**
-**   INSERT      immediate   Decrement the "immediate constraint counter".
-**
-**   DELETE      deferred    Increment the "deferred constraint counter".
-**                           Or, if the ON (UPDATE|DELETE) action is RESTRICT,
-**                           throw a "FOREIGN KEY constraint failed" exception.
-**
-**   INSERT      deferred    Decrement the "deferred constraint counter".
-**
-** These operations are identified in the comment at the top of this file 
-** (fkey.c) as "I.2" and "D.2".
-*/
-static void fkScanChildren(
-  Parse *pParse,                  /* Parse context */
-  SrcList *pSrc,                  /* The child table to be scanned */
-  Table *pTab,                    /* The parent table */
-  Index *pIdx,                    /* Index on parent covering the foreign key */
-  FKey *pFKey,                    /* The foreign key linking pSrc to pTab */
-  int *aiCol,                     /* Map from pIdx cols to child table cols */
-  int regData,                    /* Parent row 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() */
-  int iFkIfZero = 0;              /* Address of OP_FkIfZero */
-  Vdbe *v = sqlite3GetVdbe(pParse);
-
-  assert( pIdx==0 || pIdx->pTable==pTab );
-  assert( pIdx==0 || pIdx->nKeyCol==pFKey->nCol );
-  assert( pIdx!=0 || pFKey->nCol==1 );
-  assert( pIdx!=0 || HasRowid(pTab) );
-
-  if( nIncr<0 ){
-    iFkIfZero = sqlite3VdbeAddOp2(v, OP_FkIfZero, pFKey->isDeferred, 0);
-    VdbeCoverage(v);
-  }
-
-  /* Create an Expr object representing an SQL expression like:
-  **
-  **   <parent-key1> = <child-key1> AND <parent-key2> = <child-key2> ...
-  **
-  ** The collation sequence used for the comparison should be that of
-  ** the parent key columns. The affinity of the parent key column should
-  ** be applied to each child key value before the comparison takes place.
-  */
-  for(i=0; i<pFKey->nCol; i++){
-    Expr *pLeft;                  /* Value from parent table row */
-    Expr *pRight;                 /* Column ref to child table */
-    Expr *pEq;                    /* Expression (pLeft = pRight) */
-    i16 iCol;                     /* Index of column in child table */ 
-    const char *zCol;             /* Name of column in child table */
-
-    iCol = pIdx ? pIdx->aiColumn[i] : -1;
-    pLeft = exprTableRegister(pParse, pTab, regData, iCol);
-    iCol = aiCol ? aiCol[i] : pFKey->aCol[0].iFrom;
-    assert( iCol>=0 );
-    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);
-  }
-
-  /* If the child table is the same as the parent table, then add terms
-  ** to the WHERE clause that prevent this entry from being scanned.
-  ** The added WHERE clause terms are like this:
-  **
-  **     $current_rowid!=rowid
-  **     NOT( $current_a==a AND $current_b==b AND ... )
-  **
-  ** The first form is used for rowid tables.  The second form is used
-  ** for WITHOUT ROWID tables.  In the second form, the primary key is
-  ** (a,b,...)
-  */
-  if( pTab==pFKey->pFrom && nIncr>0 ){
-    Expr *pNe;                    /* Expression (pLeft != pRight) */
-    Expr *pLeft;                  /* Value from parent table row */
-    Expr *pRight;                 /* Column ref to child table */
-    if( HasRowid(pTab) ){
-      pLeft = exprTableRegister(pParse, pTab, regData, -1);
-      pRight = exprTableColumn(db, pTab, pSrc->a[0].iCursor, -1);
-      pNe = sqlite3PExpr(pParse, TK_NE, pLeft, pRight, 0);
-    }else{
-      Expr *pEq, *pAll = 0;
-      Index *pPk = sqlite3PrimaryKeyIndex(pTab);
-      assert( pIdx!=0 );
-      for(i=0; i<pPk->nKeyCol; i++){
-        i16 iCol = pIdx->aiColumn[i];
-        pLeft = exprTableRegister(pParse, pTab, regData, iCol);
-        pRight = exprTableColumn(db, pTab, pSrc->a[0].iCursor, iCol);
-        pEq = sqlite3PExpr(pParse, TK_EQ, pLeft, pRight, 0);
-        pAll = sqlite3ExprAnd(db, pAll, pEq);
-      }
-      pNe = sqlite3PExpr(pParse, TK_NOT, pAll, 0, 0);
-    }
-    pWhere = sqlite3ExprAnd(db, pWhere, pNe);
-  }
-
-  /* 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, 0, 0);
-  if( nIncr>0 && pFKey->isDeferred==0 ){
-    sqlite3ParseToplevel(pParse)->mayAbort = 1;
-  }
-  sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, nIncr);
-  if( pWInfo ){
-    sqlite3WhereEnd(pWInfo);
-  }
-
-  /* Clean up the WHERE clause constructed above. */
-  sqlite3ExprDelete(db, pWhere);
-  if( iFkIfZero ){
-    sqlite3VdbeJumpHere(v, iFkIfZero);
-  }
-}
-
-/*
-** This function returns a linked list of FKey objects (connected by
-** FKey.pNextTo) holding all children of table pTab.  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 for which t2 is the parent
-** table).
-*/
-FKey *sqlite3FkReferences(Table *pTab){
-  return (FKey *)sqlite3HashFind(&pTab->pSchema->fkeyHash, pTab->zName);
-}
-
-/*
-** The second argument is a Trigger structure allocated by the 
-** fkActionTrigger() routine. This function deletes the Trigger structure
-** and all of its sub-components.
-**
-** The Trigger structure or any of its sub-components may be allocated from
-** the lookaside buffer belonging to database handle dbMem.
-*/
-static void fkTriggerDelete(sqlite3 *dbMem, Trigger *p){
-  if( p ){
-    TriggerStep *pStep = p->step_list;
-    sqlite3ExprDelete(dbMem, pStep->pWhere);
-    sqlite3ExprListDelete(dbMem, pStep->pExprList);
-    sqlite3SelectDelete(dbMem, pStep->pSelect);
-    sqlite3ExprDelete(dbMem, p->pWhen);
-    sqlite3DbFree(dbMem, p);
-  }
-}
-
-/*
-** This function is called to generate code that runs when table pTab is
-** being dropped from the database. The SrcList passed as the second argument
-** to this function contains a single entry guaranteed to resolve to
-** table pTab.
-**
-** Normally, no code is required. However, if either
-**
-**   (a) The table is the parent table of a FK constraint, or
-**   (b) The table is the child table of a deferred FK constraint and it is
-**       determined at runtime that there are outstanding deferred FK 
-**       constraint violations in the database,
-**
-** then the equivalent of "DELETE FROM <tbl>" is executed before dropping
-** the table from the database. Triggers are disabled while running this
-** DELETE, but foreign key actions are not.
-*/
-void sqlite3FkDropTable(Parse *pParse, SrcList *pName, Table *pTab){
-  sqlite3 *db = pParse->db;
-  if( (db->flags&SQLITE_ForeignKeys) && !IsVirtual(pTab) && !pTab->pSelect ){
-    int iSkip = 0;
-    Vdbe *v = sqlite3GetVdbe(pParse);
-
-    assert( v );                  /* VDBE has already been allocated */
-    if( sqlite3FkReferences(pTab)==0 ){
-      /* Search for a deferred foreign key constraint for which this table
-      ** is the child table. If one cannot be found, return without 
-      ** generating any VDBE code. If one can be found, then jump over
-      ** the entire DELETE if there are no outstanding deferred constraints
-      ** when this statement is run.  */
-      FKey *p;
-      for(p=pTab->pFKey; p; p=p->pNextFrom){
-        if( p->isDeferred || (db->flags & SQLITE_DeferFKs) ) break;
-      }
-      if( !p ) return;
-      iSkip = sqlite3VdbeMakeLabel(v);
-      sqlite3VdbeAddOp2(v, OP_FkIfZero, 1, iSkip); VdbeCoverage(v);
-    }
-
-    pParse->disableTriggers = 1;
-    sqlite3DeleteFrom(pParse, sqlite3SrcListDup(db, pName, 0), 0);
-    pParse->disableTriggers = 0;
-
-    /* If the DELETE has generated immediate foreign key constraint 
-    ** violations, halt the VDBE and return an error at this point, before
-    ** any modifications to the schema are made. This is because statement
-    ** transactions are not able to rollback schema changes.  
-    **
-    ** If the SQLITE_DeferFKs flag is set, then this is not required, as
-    ** the statement transaction will not be rolled back even if FK
-    ** constraints are violated.
-    */
-    if( (db->flags & SQLITE_DeferFKs)==0 ){
-      sqlite3VdbeAddOp2(v, OP_FkIfZero, 0, sqlite3VdbeCurrentAddr(v)+2);
-      VdbeCoverage(v);
-      sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_FOREIGNKEY,
-          OE_Abort, 0, P4_STATIC, P5_ConstraintFK);
-    }
-
-    if( iSkip ){
-      sqlite3VdbeResolveLabel(v, iSkip);
-    }
-  }
-}
-
-
-/*
-** The second argument points to an FKey object representing a foreign key
-** for which pTab is the child table. An UPDATE statement against pTab
-** is currently being processed. For each column of the table that is 
-** actually updated, the corresponding element in the aChange[] array
-** is zero or greater (if a column is unmodified the corresponding element
-** is set to -1). If the rowid column is modified by the UPDATE statement
-** the bChngRowid argument is non-zero.
-**
-** This function returns true if any of the columns that are part of the
-** child key for FK constraint *p are modified.
-*/
-static int fkChildIsModified(
-  Table *pTab,                    /* Table being updated */
-  FKey *p,                        /* Foreign key for which pTab is the child */
-  int *aChange,                   /* Array indicating modified columns */
-  int bChngRowid                  /* True if rowid is modified by this update */
-){
-  int i;
-  for(i=0; i<p->nCol; i++){
-    int iChildKey = p->aCol[i].iFrom;
-    if( aChange[iChildKey]>=0 ) return 1;
-    if( iChildKey==pTab->iPKey && bChngRowid ) return 1;
-  }
-  return 0;
-}
-
-/*
-** The second argument points to an FKey object representing a foreign key
-** for which pTab is the parent table. An UPDATE statement against pTab
-** is currently being processed. For each column of the table that is 
-** actually updated, the corresponding element in the aChange[] array
-** is zero or greater (if a column is unmodified the corresponding element
-** is set to -1). If the rowid column is modified by the UPDATE statement
-** the bChngRowid argument is non-zero.
-**
-** This function returns true if any of the columns that are part of the
-** parent key for FK constraint *p are modified.
-*/
-static int fkParentIsModified(
-  Table *pTab, 
-  FKey *p, 
-  int *aChange, 
-  int bChngRowid
-){
-  int i;
-  for(i=0; i<p->nCol; i++){
-    char *zKey = p->aCol[i].zCol;
-    int iKey;
-    for(iKey=0; iKey<pTab->nCol; iKey++){
-      if( aChange[iKey]>=0 || (iKey==pTab->iPKey && bChngRowid) ){
-        Column *pCol = &pTab->aCol[iKey];
-        if( zKey ){
-          if( 0==sqlite3StrICmp(pCol->zName, zKey) ) return 1;
-        }else if( pCol->colFlags & COLFLAG_PRIMKEY ){
-          return 1;
-        }
-      }
-    }
-  }
-  return 0;
-}
-
-/*
-** This function is called when inserting, deleting or updating a row of
-** table pTab to generate VDBE code to perform foreign key constraint 
-** processing for the operation.
-**
-** For a DELETE operation, parameter regOld is passed the index of the
-** first register in an array of (pTab->nCol+1) registers containing the
-** rowid of the row being deleted, followed by each of the column values
-** of the row being deleted, from left to right. Parameter regNew is passed
-** zero in this case.
-**
-** For an INSERT operation, regOld is passed zero and regNew is passed the
-** first register of an array of (pTab->nCol+1) registers containing the new
-** row data.
-**
-** For an UPDATE operation, this function is called twice. Once before
-** the original record is deleted from the table using the calling convention
-** described for DELETE. Then again after the original record is deleted
-** but before the new record is inserted using the INSERT convention. 
-*/
-void sqlite3FkCheck(
-  Parse *pParse,                  /* Parse context */
-  Table *pTab,                    /* Row is being deleted from this table */ 
-  int regOld,                     /* Previous row data is stored here */
-  int regNew,                     /* New row data is stored here */
-  int *aChange,                   /* Array indicating UPDATEd columns (or 0) */
-  int bChngRowid                  /* True if rowid is UPDATEd */
-){
-  sqlite3 *db = pParse->db;       /* Database handle */
-  FKey *pFKey;                    /* Used to iterate through FKs */
-  int iDb;                        /* Index of database containing pTab */
-  const char *zDb;                /* Name of database containing pTab */
-  int isIgnoreErrors = pParse->disableTriggers;
-
-  /* Exactly one of regOld and regNew should be non-zero. */
-  assert( (regOld==0)!=(regNew==0) );
-
-  /* If foreign-keys are disabled, this function is a no-op. */
-  if( (db->flags&SQLITE_ForeignKeys)==0 ) return;
-
-  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
-  zDb = db->aDb[iDb].zName;
-
-  /* Loop through all the foreign key constraints for which pTab is the
-  ** child table (the table that the foreign key definition is part of).  */
-  for(pFKey=pTab->pFKey; pFKey; pFKey=pFKey->pNextFrom){
-    Table *pTo;                   /* Parent table of foreign key pFKey */
-    Index *pIdx = 0;              /* Index on key columns in pTo */
-    int *aiFree = 0;
-    int *aiCol;
-    int iCol;
-    int i;
-    int isIgnore = 0;
-
-    if( aChange 
-     && sqlite3_stricmp(pTab->zName, pFKey->zTo)!=0
-     && fkChildIsModified(pTab, pFKey, aChange, bChngRowid)==0 
-    ){
-      continue;
-    }
-
-    /* Find the parent table of this foreign key. Also find a unique index 
-    ** on the parent key columns in the parent table. If either of these 
-    ** schema items cannot be located, set an error in pParse and return 
-    ** early.  */
-    if( pParse->disableTriggers ){
-      pTo = sqlite3FindTable(db, pFKey->zTo, zDb);
-    }else{
-      pTo = sqlite3LocateTable(pParse, 0, pFKey->zTo, zDb);
-    }
-    if( !pTo || sqlite3FkLocateIndex(pParse, pTo, pFKey, &pIdx, &aiFree) ){
-      assert( isIgnoreErrors==0 || (regOld!=0 && regNew==0) );
-      if( !isIgnoreErrors || db->mallocFailed ) return;
-      if( pTo==0 ){
-        /* If isIgnoreErrors is true, then a table is being dropped. In this
-        ** case SQLite runs a "DELETE FROM xxx" on the table being dropped
-        ** before actually dropping it in order to check FK constraints.
-        ** If the parent table of an FK constraint on the current table is
-        ** missing, behave as if it is empty. i.e. decrement the relevant
-        ** FK counter for each row of the current table with non-NULL keys.
-        */
-        Vdbe *v = sqlite3GetVdbe(pParse);
-        int iJump = sqlite3VdbeCurrentAddr(v) + pFKey->nCol + 1;
-        for(i=0; i<pFKey->nCol; i++){
-          int iReg = pFKey->aCol[i].iFrom + regOld + 1;
-          sqlite3VdbeAddOp2(v, OP_IsNull, iReg, iJump); VdbeCoverage(v);
-        }
-        sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, -1);
-      }
-      continue;
-    }
-    assert( pFKey->nCol==1 || (aiFree && pIdx) );
-
-    if( aiFree ){
-      aiCol = aiFree;
-    }else{
-      iCol = pFKey->aCol[0].iFrom;
-      aiCol = &iCol;
-    }
-    for(i=0; i<pFKey->nCol; i++){
-      if( aiCol[i]==pTab->iPKey ){
-        aiCol[i] = -1;
-      }
-#ifndef SQLITE_OMIT_AUTHORIZATION
-      /* Request permission to read the parent key columns. If the 
-      ** authorization callback returns SQLITE_IGNORE, behave as if any
-      ** values read from the parent table are NULL. */
-      if( db->xAuth ){
-        int rcauth;
-        char *zCol = pTo->aCol[pIdx ? pIdx->aiColumn[i] : pTo->iPKey].zName;
-        rcauth = sqlite3AuthReadCol(pParse, pTo->zName, zCol, iDb);
-        isIgnore = (rcauth==SQLITE_IGNORE);
-      }
-#endif
-    }
-
-    /* Take a shared-cache advisory read-lock on the parent table. Allocate 
-    ** a cursor to use to search the unique index on the parent key columns 
-    ** in the parent table.  */
-    sqlite3TableLock(pParse, iDb, pTo->tnum, 0, pTo->zName);
-    pParse->nTab++;
-
-    if( regOld!=0 ){
-      /* A row is being removed from the child table. Search for the parent.
-      ** If the parent does not exist, removing the child row resolves an 
-      ** outstanding foreign key constraint violation. */
-      fkLookupParent(pParse, iDb, pTo, pIdx, pFKey, aiCol, regOld, -1,isIgnore);
-    }
-    if( regNew!=0 ){
-      /* A row is being added to the child table. If a parent row cannot
-      ** be found, adding the child row has violated the FK constraint. */ 
-      fkLookupParent(pParse, iDb, pTo, pIdx, pFKey, aiCol, regNew, +1,isIgnore);
-    }
-
-    sqlite3DbFree(db, aiFree);
-  }
-
-  /* Loop through all the foreign key constraints that refer to this table.
-  ** (the "child" constraints) */
-  for(pFKey = sqlite3FkReferences(pTab); pFKey; pFKey=pFKey->pNextTo){
-    Index *pIdx = 0;              /* Foreign key index for pFKey */
-    SrcList *pSrc;
-    int *aiCol = 0;
-
-    if( aChange && fkParentIsModified(pTab, pFKey, aChange, bChngRowid)==0 ){
-      continue;
-    }
-
-    if( !pFKey->isDeferred && !(db->flags & SQLITE_DeferFKs) 
-     && !pParse->pToplevel && !pParse->isMultiWrite 
-    ){
-      assert( regOld==0 && regNew!=0 );
-      /* Inserting a single row into a parent table cannot cause an immediate
-      ** foreign key violation. So do nothing in this case.  */
-      continue;
-    }
-
-    if( sqlite3FkLocateIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ){
-      if( !isIgnoreErrors || db->mallocFailed ) return;
-      continue;
-    }
-    assert( aiCol || pFKey->nCol==1 );
-
-    /* Create a SrcList structure containing the child table.  We need the
-    ** child table as a SrcList for sqlite3WhereBegin() */
-    pSrc = sqlite3SrcListAppend(db, 0, 0, 0);
-    if( pSrc ){
-      struct SrcList_item *pItem = pSrc->a;
-      pItem->pTab = pFKey->pFrom;
-      pItem->zName = pFKey->pFrom->zName;
-      pItem->pTab->nRef++;
-      pItem->iCursor = pParse->nTab++;
-  
-      if( regNew!=0 ){
-        fkScanChildren(pParse, pSrc, pTab, pIdx, pFKey, aiCol, regNew, -1);
-      }
-      if( regOld!=0 ){
-        /* If there is a RESTRICT action configured for the current operation
-        ** on the parent 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.  */
-        fkScanChildren(pParse, pSrc, pTab, pIdx, pFKey, aiCol, regOld, 1);
-      }
-      pItem->zName = 0;
-      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.
-*/
-u32 sqlite3FkOldmask(
-  Parse *pParse,                  /* Parse context */
-  Table *pTab                     /* Table being modified */
-){
-  u32 mask = 0;
-  if( pParse->db->flags&SQLITE_ForeignKeys ){
-    FKey *p;
-    int i;
-    for(p=pTab->pFKey; p; p=p->pNextFrom){
-      for(i=0; i<p->nCol; i++) mask |= COLUMN_MASK(p->aCol[i].iFrom);
-    }
-    for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){
-      Index *pIdx = 0;
-      sqlite3FkLocateIndex(pParse, pTab, p, &pIdx, 0);
-      if( pIdx ){
-        for(i=0; i<pIdx->nKeyCol; 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 a DELETE, then
-** parameter aChange is passed a NULL value. For an UPDATE, aChange points
-** to an array of size N, where N is the number of columns in table pTab.
-** If the i'th column is not modified by the UPDATE, then the corresponding 
-** entry in the aChange[] array is set to -1. If the column is modified,
-** the value is 0 or greater. Parameter chngRowid is set to true if the
-** UPDATE statement modifies the rowid fields of the table.
-**
-** 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 */
-  int *aChange,                   /* Non-NULL for UPDATE operations */
-  int chngRowid                   /* True for UPDATE that affects rowid */
-){
-  if( pParse->db->flags&SQLITE_ForeignKeys ){
-    if( !aChange ){
-      /* A DELETE operation. Foreign key processing is required if the 
-      ** table in question is either the child or parent table for any 
-      ** foreign key constraint.  */
-      return (sqlite3FkReferences(pTab) || pTab->pFKey);
-    }else{
-      /* This is an UPDATE. Foreign key processing is only required if the
-      ** operation modifies one or more child or parent key columns. */
-      FKey *p;
-
-      /* Check if any child key columns are being modified. */
-      for(p=pTab->pFKey; p; p=p->pNextFrom){
-        if( fkChildIsModified(pTab, p, aChange, chngRowid) ) return 1;
-      }
-
-      /* Check if any parent key columns are being modified. */
-      for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){
-        if( fkParentIsModified(pTab, p, aChange, chngRowid) ) return 1;
-      }
-    }
-  }
-  return 0;
-}
-
-/*
-** This function is called when an UPDATE or DELETE operation is being 
-** compiled on table pTab, which is the parent table of foreign-key pFKey.
-** If the current operation is an UPDATE, then the pChanges parameter is
-** passed a pointer to the list of columns being modified. If it is a
-** DELETE, pChanges is passed a NULL pointer.
-**
-** It returns a pointer to a Trigger structure containing a trigger
-** equivalent to the ON UPDATE or ON DELETE action specified by pFKey.
-** If the action is "NO ACTION" or "RESTRICT", then a NULL pointer is
-** returned (these actions require no special handling by the triggers
-** sub-system, code for them is created by fkScanChildren()).
-**
-** For example, if pFKey is the foreign key and pTab is table "p" in 
-** the following schema:
-**
-**   CREATE TABLE p(pk PRIMARY KEY);
-**   CREATE TABLE c(ck REFERENCES p ON DELETE CASCADE);
-**
-** then the returned trigger structure is equivalent to:
-**
-**   CREATE TRIGGER ... DELETE ON p BEGIN
-**     DELETE FROM c WHERE ck = old.pk;
-**   END;
-**
-** The returned pointer is cached as part of the foreign key object. It
-** is eventually freed along with the rest of the foreign key object by 
-** sqlite3FkDelete().
-*/
-static Trigger *fkActionTrigger(
-  Parse *pParse,                  /* Parse context */
-  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;                     /* One of OE_None, OE_Cascade etc. */
-  Trigger *pTrigger;              /* Trigger definition to return */
-  int iAction = (pChanges!=0);    /* 1 for UPDATE, 0 for DELETE */
-
-  action = pFKey->aAction[iAction];
-  pTrigger = pFKey->apTrigger[iAction];
-
-  if( action!=OE_None && !pTrigger ){
-    u8 enableLookaside;           /* Copy of db->lookaside.bEnabled */
-    char const *zFrom;            /* Name of child table */
-    int nFrom;                    /* Length in bytes of zFrom */
-    Index *pIdx = 0;              /* Parent key index for this FK */
-    int *aiCol = 0;               /* child table cols -> parent key cols */
-    TriggerStep *pStep = 0;        /* First (only) step of trigger program */
-    Expr *pWhere = 0;             /* WHERE clause of trigger step */
-    ExprList *pList = 0;          /* Changes list if ON UPDATE CASCADE */
-    Select *pSelect = 0;          /* If RESTRICT, "SELECT RAISE(...)" */
-    int i;                        /* Iterator variable */
-    Expr *pWhen = 0;              /* WHEN clause for the trigger */
-
-    if( sqlite3FkLocateIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ) return 0;
-    assert( aiCol || pFKey->nCol==1 );
-
-    for(i=0; i<pFKey->nCol; i++){
-      Token tOld = { "old", 3 };  /* Literal "old" token */
-      Token tNew = { "new", 3 };  /* Literal "new" token */
-      Token tFromCol;             /* Name of column in child table */
-      Token tToCol;               /* Name of column in parent table */
-      int iFromCol;               /* Idx of column in child table */
-      Expr *pEq;                  /* tFromCol = OLD.tToCol */
-
-      iFromCol = aiCol ? aiCol[i] : pFKey->aCol[0].iFrom;
-      assert( iFromCol>=0 );
-      tToCol.z = pIdx ? pTab->aCol[pIdx->aiColumn[i]].zName : "oid";
-      tFromCol.z = pFKey->pFrom->aCol[iFromCol].zName;
-
-      tToCol.n = sqlite3Strlen30(tToCol.z);
-      tFromCol.n = sqlite3Strlen30(tFromCol.z);
-
-      /* Create the expression "OLD.zToCol = zFromCol". It is important
-      ** that the "OLD.zToCol" term is on the LHS of the = operator, so
-      ** that the affinity and collation sequence associated with the
-      ** parent table are used for the comparison. */
-      pEq = sqlite3PExpr(pParse, TK_EQ,
-          sqlite3PExpr(pParse, TK_DOT, 
-            sqlite3PExpr(pParse, TK_ID, 0, 0, &tOld),
-            sqlite3PExpr(pParse, TK_ID, 0, 0, &tToCol)
-          , 0),
-          sqlite3PExpr(pParse, TK_ID, 0, 0, &tFromCol)
-      , 0);
-      pWhere = sqlite3ExprAnd(db, pWhere, pEq);
-
-      /* For ON UPDATE, construct the next term of the WHEN clause.
-      ** The final WHEN clause will be like this:
-      **
-      **    WHEN NOT(old.col1 IS new.col1 AND ... AND old.colN IS new.colN)
-      */
-      if( pChanges ){
-        pEq = sqlite3PExpr(pParse, TK_IS,
-            sqlite3PExpr(pParse, TK_DOT, 
-              sqlite3PExpr(pParse, TK_ID, 0, 0, &tOld),
-              sqlite3PExpr(pParse, TK_ID, 0, 0, &tToCol),
-              0),
-            sqlite3PExpr(pParse, TK_DOT, 
-              sqlite3PExpr(pParse, TK_ID, 0, 0, &tNew),
-              sqlite3PExpr(pParse, TK_ID, 0, 0, &tToCol),
-              0),
-            0);
-        pWhen = sqlite3ExprAnd(db, pWhen, pEq);
-      }
-  
-      if( action!=OE_Restrict && (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 = pFKey->pFrom->aCol[iFromCol].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(db, aiCol);
-
-    zFrom = pFKey->pFrom->zName;
-    nFrom = sqlite3Strlen30(zFrom);
-
-    if( action==OE_Restrict ){
-      Token tFrom;
-      Expr *pRaise; 
-
-      tFrom.z = zFrom;
-      tFrom.n = nFrom;
-      pRaise = sqlite3Expr(db, TK_RAISE, "FOREIGN KEY constraint failed");
-      if( pRaise ){
-        pRaise->affinity = OE_Abort;
-      }
-      pSelect = sqlite3SelectNew(pParse, 
-          sqlite3ExprListAppend(pParse, 0, pRaise),
-          sqlite3SrcListAppend(db, 0, &tFrom, 0),
-          pWhere,
-          0, 0, 0, 0, 0, 0
-      );
-      pWhere = 0;
-    }
-
-    /* Disable lookaside memory allocation */
-    enableLookaside = db->lookaside.bEnabled;
-    db->lookaside.bEnabled = 0;
-
-    pTrigger = (Trigger *)sqlite3DbMallocZero(db, 
-        sizeof(Trigger) +         /* struct Trigger */
-        sizeof(TriggerStep) +     /* Single step in trigger program */
-        nFrom + 1                 /* Space for pStep->target.z */
-    );
-    if( pTrigger ){
-      pStep = pTrigger->step_list = (TriggerStep *)&pTrigger[1];
-      pStep->target.z = (char *)&pStep[1];
-      pStep->target.n = nFrom;
-      memcpy((char *)pStep->target.z, zFrom, nFrom);
-  
-      pStep->pWhere = sqlite3ExprDup(db, pWhere, EXPRDUP_REDUCE);
-      pStep->pExprList = sqlite3ExprListDup(db, pList, EXPRDUP_REDUCE);
-      pStep->pSelect = sqlite3SelectDup(db, pSelect, EXPRDUP_REDUCE);
-      if( pWhen ){
-        pWhen = sqlite3PExpr(pParse, TK_NOT, pWhen, 0, 0);
-        pTrigger->pWhen = sqlite3ExprDup(db, pWhen, EXPRDUP_REDUCE);
-      }
-    }
-
-    /* Re-enable the lookaside buffer, if it was disabled earlier. */
-    db->lookaside.bEnabled = enableLookaside;
-
-    sqlite3ExprDelete(db, pWhere);
-    sqlite3ExprDelete(db, pWhen);
-    sqlite3ExprListDelete(db, pList);
-    sqlite3SelectDelete(db, pSelect);
-    if( db->mallocFailed==1 ){
-      fkTriggerDelete(db, pTrigger);
-      return 0;
-    }
-    assert( pStep!=0 );
-
-    switch( action ){
-      case OE_Restrict:
-        pStep->op = TK_SELECT; 
-        break;
-      case OE_Cascade: 
-        if( !pChanges ){ 
-          pStep->op = TK_DELETE; 
-          break; 
-        }
-      default:
-        pStep->op = TK_UPDATE;
-    }
-    pStep->pTrig = pTrigger;
-    pTrigger->pSchema = pTab->pSchema;
-    pTrigger->pTabSchema = pTab->pSchema;
-    pFKey->apTrigger[iAction] = pTrigger;
-    pTrigger->op = (pChanges ? TK_UPDATE : TK_DELETE);
-  }
-
-  return pTrigger;
-}
-
-/*
-** 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 */
-  int *aChange,                   /* Array indicating UPDATEd columns (or 0) */
-  int bChngRowid                  /* True if rowid is UPDATEd */
-){
-  /* 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 = sqlite3FkReferences(pTab); pFKey; pFKey=pFKey->pNextTo){
-      if( aChange==0 || fkParentIsModified(pTab, pFKey, aChange, bChngRowid) ){
-        Trigger *pAct = fkActionTrigger(pParse, pTab, pFKey, pChanges);
-        if( pAct ){
-          sqlite3CodeRowTriggerDirect(pParse, pAct, pTab, regOld, OE_Abort, 0);
-        }
-      }
-    }
-  }
-}
-
-#endif /* ifndef SQLITE_OMIT_TRIGGER */
-
-/*
-** 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(sqlite3 *db, Table *pTab){
-  FKey *pFKey;                    /* Iterator variable */
-  FKey *pNext;                    /* Copy of pFKey->pNextFrom */
-
-  assert( db==0 || sqlite3SchemaMutexHeld(db, 0, pTab->pSchema) );
-  for(pFKey=pTab->pFKey; pFKey; pFKey=pNext){
-
-    /* Remove the FK from the fkeyHash hash table. */
-    if( !db || db->pnBytesFreed==0 ){
-      if( pFKey->pPrevTo ){
-        pFKey->pPrevTo->pNextTo = pFKey->pNextTo;
-      }else{
-        void *p = (void *)pFKey->pNextTo;
-        const char *z = (p ? pFKey->pNextTo->zTo : pFKey->zTo);
-        sqlite3HashInsert(&pTab->pSchema->fkeyHash, z, p);
-      }
-      if( pFKey->pNextTo ){
-        pFKey->pNextTo->pPrevTo = pFKey->pPrevTo;
-      }
-    }
-
-    /* EV: R-30323-21917 Each foreign key constraint in SQLite is
-    ** classified as either immediate or deferred.
-    */
-    assert( pFKey->isDeferred==0 || pFKey->isDeferred==1 );
-
-    /* Delete any triggers created to implement actions for this FK. */
-#ifndef SQLITE_OMIT_TRIGGER
-    fkTriggerDelete(db, pFKey->apTrigger[0]);
-    fkTriggerDelete(db, pFKey->apTrigger[1]);
-#endif
-
-    pNext = pFKey->pNextFrom;
-    sqlite3DbFree(db, pFKey);
-  }
-}
-#endif /* ifndef SQLITE_OMIT_FOREIGN_KEY */