[sql] Import reference version of SQLite 3.8.7.4.

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

 /*
 **
 ** 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
-** is returned and the current statement transaction rolled back. If a 
+** 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
@@ skipping 43 matching lines @@
 **
 ** 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
+** 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?
 **
 **
@@ skipping 35 matching lines @@
 **   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 a unique index on the parent key columns. 
+** 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 a different number of columns to the child key in 
+**      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.
 */
-static int locateFkeyIndex(
+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 */
@@ skipping 24 matching lines @@
       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->nColumn==nCol && pIdx->onError!=OE_None ){ 
+    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 (Index.autoIndex==2).  */
-        if( pIdx->autoIndex==2 ){
+        ** 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++){
-          int iCol = pIdx->aiColumn[i];     /* Index of column in parent tbl */
+          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");
+      sqlite3ErrorMsg(pParse,
+           "foreign key mismatch - \"%w\" referencing \"%w\"",
+           pFKey->pFrom->zName, pFKey->zTo);
     }
     sqlite3DbFree(pParse->db, aiCol);
     return 1;
   }
 
   *ppIdx = pIdx;
   return 0;
 }
 
 /*
@@ skipping 40 matching lines @@
 
   /* 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);
+    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);
+        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);
+      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);
-      KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
   
       sqlite3VdbeAddOp3(v, OP_OpenRead, iCur, pIdx->tnum, iDb);
-      sqlite3VdbeChangeP4(v, -1, (char*)pKey, P4_KEYINFO_HANDOFF);
+      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.  */
+      ** 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;
-          sqlite3VdbeAddOp3(v, OP_Ne, iChild, iJump, iParent);
+          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);
       }
   
-      sqlite3VdbeAddOp3(v, OP_MakeRecord, regTemp, nCol, regRec);
-      sqlite3VdbeChangeP4(v, -1, sqlite3IndexAffinityStr(v,pIdx), P4_TRANSIENT);
-      sqlite3VdbeAddOp4Int(v, OP_Found, iCur, iOk, regRec, 0);
+      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->pToplevel && !pParse->isMultiWrite ){
+  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, OE_Abort, "foreign key constraint failed", P4_STATIC
-    );
+    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.
+**                           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.
+**                           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,                  /* SrcList containing the table to scan */
-  Table *pTab,
-  Index *pIdx,                    /* Foreign key index */
-  FKey *pFKey,                    /* Foreign key relationship */
+  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,                    /* Referenced table data starts here */
+  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 || pIdx->pTable==pTab );
+  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) */
-    int iCol;                     /* Index of column in child table */ 
+    i16 iCol;                     /* Index of column in child table */ 
     const char *zCol;             /* Name of column in child table */
 
-    pLeft = sqlite3Expr(db, TK_REGISTER, 0);
-    if( pLeft ){
-      /* Set the collation sequence and affinity of the LHS of each TK_EQ
-      ** expression to the parent key column defaults.  */
-      if( pIdx ){
-        Column *pCol;
-        iCol = pIdx->aiColumn[i];
-        pCol = &pTab->aCol[iCol];
-        if( pTab->iPKey==iCol ) iCol = -1;
-        pLeft->iTable = regData+iCol+1;
-        pLeft->affinity = pCol->affinity;
-        pLeft->pColl = sqlite3LocateCollSeq(pParse, pCol->zColl);
-      }else{
-        pLeft->iTable = regData;
-        pLeft->affinity = SQLITE_AFF_INTEGER;
-      }
-    }
+    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, and this scan
-  ** is taking place as part of a DELETE operation (operation D.2), omit the
-  ** row being deleted from the scan by adding ($rowid != rowid) to the WHERE 
-  ** clause, where $rowid is the rowid of the row being deleted.  */
+  /* 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 *pEq;                    /* Expression (pLeft = pRight) */
+    Expr *pNe;                    /* Expression (pLeft != pRight) */
     Expr *pLeft;                  /* Value from parent table row */
     Expr *pRight;                 /* Column ref to child table */
-    pLeft = sqlite3Expr(db, TK_REGISTER, 0);
-    pRight = sqlite3Expr(db, TK_COLUMN, 0);
-    if( pLeft && pRight ){
-      pLeft->iTable = regData;
-      pLeft->affinity = SQLITE_AFF_INTEGER;
-      pRight->iTable = pSrc->a[0].iCursor;
-      pRight->iColumn = -1;
+    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);
     }
-    pEq = sqlite3PExpr(pParse, TK_NE, pLeft, pRight, 0);
-    pWhere = sqlite3ExprAnd(db, pWhere, pEq);
+    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);
+  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 pointer to the head of a linked list of FK
-** constraints for which table pTab is the parent table. For example,
+** 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){
-  int nName = sqlite3Strlen30(pTab->zName);
-  return (FKey *)sqlite3HashFind(&pTab->pSchema->fkeyHash, pTab->zName, nName);
+  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.
 */
@@ skipping 33 matching lines @@
 
     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 ) break;
+        if( p->isDeferred || (db->flags & SQLITE_DeferFKs) ) break;
       }
       if( !p ) return;
       iSkip = sqlite3VdbeMakeLabel(v);
-      sqlite3VdbeAddOp2(v, OP_FkIfZero, 1, iSkip);
+      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.  */
-    sqlite3VdbeAddOp2(v, OP_FkIfZero, 0, sqlite3VdbeCurrentAddr(v)+2);
-    sqlite3HaltConstraint(
-        pParse, OE_Abort, "foreign key constraint failed", P4_STATIC
-    );
+    ** 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 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 || locateFkeyIndex(pParse, pTo, pFKey, &pIdx, &aiFree) ){
+    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;
     }
@@ skipping 28 matching lines @@
     }
     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 */
+  /* 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( !pFKey->isDeferred && !pParse->pToplevel && !pParse->isMultiWrite ){
+    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( locateFkeyIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ){
+    if( sqlite3FkLocateIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ){
       if( !isIgnoreErrors || db->mallocFailed ) return;
       continue;
     }
     assert( aiCol || pFKey->nCol==1 );
 
-    /* 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.  */
+    /* 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);
@@ skipping 26 matching lines @@
 ){
   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;
-      locateFkeyIndex(pParse, pTab, p, &pIdx, 0);
+      sqlite3FkLocateIndex(pParse, pTab, p, &pIdx, 0);
       if( pIdx ){
-        for(i=0; i<pIdx->nColumn; i++) mask |= COLUMN_MASK(pIdx->aiColumn[i]);
+        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. */
-      int i;
       FKey *p;
 
       /* Check if any child key columns are being modified. */
       for(p=pTab->pFKey; p; p=p->pNextFrom){
-        for(i=0; i<p->nCol; i++){
-          int iChildKey = p->aCol[i].iFrom;
-          if( aChange[iChildKey]>=0 ) return 1;
-          if( iChildKey==pTab->iPKey && chngRowid ) return 1;
-        }
+        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){
-        for(i=0; i<p->nCol; i++){
-          char *zKey = p->aCol[i].zCol;
-          int iKey;
-          for(iKey=0; iKey<pTab->nCol; iKey++){
-            Column *pCol = &pTab->aCol[iKey];
-            if( (zKey ? !sqlite3StrICmp(pCol->zName, zKey) : pCol->isPrimKey) ){
-              if( aChange[iKey]>=0 ) return 1;
-              if( iKey==pTab->iPKey && chngRowid ) return 1;
-            }
-          }
-        }
+        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
@@ skipping 42 matching lines @@
     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( locateFkeyIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ) return 0;
+    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 */
 
@@ skipping 62 matching lines @@
 
     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");
+      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;
@@ skipping 27 matching lines @@
     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; 
         }
@@ skipping 11 matching lines @@
 }
 
 /*
 ** 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 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){
-      Trigger *pAction = fkActionTrigger(pParse, pTab, pFKey, pChanges);
-      if( pAction ){
-        sqlite3CodeRowTriggerDirect(pParse, pAction, pTab, regOld, OE_Abort, 0);
+      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, sqlite3Strlen30(z), p);
+        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 */