*prNotFound = rMayHaveNull = ++pParse->nMem;
      sqlite4VdbeAddOp2(v, OP_Null, 0, *prNotFound);
    }else{
      testcase( pParse->nQueryLoop>0 );
      pParse->nQueryLoop = 0;
      *piCov = 0;
    }
    sqlite4CodeSubselect(pParse, pX, rMayHaveNull, eType==IN_INDEX_ROWID);
    pParse->nQueryLoop = savedNQueryLoop;
  }else{
    pX->iTable = iTab;
  }
  return eType;
}
#endif
................................................................................
** For a SELECT or EXISTS operator, return the register that holds the
** result.  For IN operators or if an error occurs, the return value is 0.
*/
#ifndef SQLITE4_OMIT_SUBQUERY
int sqlite4CodeSubselect(
  Parse *pParse,          /* Parsing context */
  Expr *pExpr,            /* The IN, SELECT, or EXISTS operator */
  int rMayHaveNull,       /* Register that records whether NULLs exist in RHS */
  int isRowid             /* If true, LHS of IN operator is a rowid */
){
  int testAddr = -1;                      /* One-time test address */
  int rReg = 0;                           /* Register storing resulting */
  Vdbe *v = sqlite4GetVdbe(pParse);
  if( NEVER(v==0) ) return 0;
  sqlite4ExprCachePush(pParse);

................................................................................
      ** column is used to build the index keys. If both 'x' and the
      ** SELECT... statement are columns, then numeric affinity is used
      ** if either column has NUMERIC or INTEGER affinity. If neither
      ** 'x' nor the SELECT... statement are columns, then numeric affinity
      ** is used.
      */
      pExpr->iTable = pParse->nTab++;
      addr = sqlite4VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, !isRowid);
      memset(&keyInfo, 0, sizeof(keyInfo));
      keyInfo.nField = 1;

      if( ExprHasProperty(pExpr, EP_xIsSelect) ){
        /* Case 1:     expr IN (SELECT ...)
        **
        ** Generate code to write the results of the select into the temporary
        ** table allocated and opened above.
        */
        SelectDest dest;
        ExprList *pEList;

        assert( !isRowid );
        sqlite4SelectDestInit(&dest, SRT_Set, pExpr->iTable);
        dest.affinity = (u8)affinity;
        assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
        pExpr->x.pSelect->iLimit = 0;
        if( sqlite4Select(pParse, pExpr->x.pSelect, &dest) ){
          return 0;
        }
................................................................................
        ** store it in the temporary table. If <expr> is a column, then use
        ** that columns affinity when building index keys. If <expr> is not
        ** a column, use numeric affinity.
        */
        int i;
        ExprList *pList = pExpr->x.pList;
        ExprListItem *pItem;
        int r1, r2, r3;

        if( !affinity ){
          affinity = SQLITE4_AFF_NONE;
        }
        keyInfo.aColl[0] = sqlite4ExprCollSeq(pParse, pExpr->pLeft);

        /* Loop through each expression in <exprlist>. */
................................................................................
          */
          if( testAddr>=0 && !sqlite4ExprIsConstant(pE2) ){
            sqlite4VdbeChangeToNoop(v, testAddr);
            testAddr = -1;
          }

          /* Evaluate the expression and insert it into the temp table */
          if( isRowid && sqlite4ExprIsInteger(pE2, &iValToIns) ){
            sqlite4VdbeAddOp3(v, OP_InsertInt, pExpr->iTable, r2, iValToIns);
          }else{
            r3 = sqlite4ExprCodeTarget(pParse, pE2, r1);
            if( isRowid ){
              sqlite4VdbeAddOp2(v, OP_MustBeInt, r3,
                                sqlite4VdbeCurrentAddr(v)+2);
              sqlite4VdbeAddOp3(v, OP_Insert, pExpr->iTable, r2, r3);
            }else{
              int r4 = sqlite4GetTempReg(pParse);
              sqlite4VdbeAddOp2(v, OP_MakeKey, pExpr->iTable, r4);
              sqlite4VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1);
              sqlite4ExprCacheAffinityChange(pParse, r3, 1);
              sqlite4VdbeAddOp3(v, OP_IdxInsert, pExpr->iTable, r2, r4);
              sqlite4ReleaseTempReg(pParse, r4);
            }
          }
        }
        sqlite4ReleaseTempReg(pParse, r1);
        sqlite4ReleaseTempReg(pParse, r2);
      }
      if( !isRowid ){
        sqlite4VdbeChangeP4(v, addr, (void *)&keyInfo, P4_KEYINFO);
      }
      break;
    }

    case TK_EXISTS:
    case TK_SELECT:
    default: {
      /* If this has to be a scalar SELECT.  Generate code to put the
................................................................................
      break;
    }
#ifndef SQLITE4_OMIT_SUBQUERY
    case TK_EXISTS:
    case TK_SELECT: {
      testcase( op==TK_EXISTS );
      testcase( op==TK_SELECT );
      inReg = sqlite4CodeSubselect(pParse, pExpr, 0, 0);
      break;
    }
    case TK_IN: {
      int destIfFalse = sqlite4VdbeMakeLabel(v);
      int destIfNull = sqlite4VdbeMakeLabel(v);
      sqlite4VdbeAddOp2(v, OP_Null, 0, target);
      sqlite4ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);

      *prNotFound = rMayHaveNull = ++pParse->nMem;
      sqlite4VdbeAddOp2(v, OP_Null, 0, *prNotFound);
    }else{
      testcase( pParse->nQueryLoop>0 );
      pParse->nQueryLoop = 0;
      *piCov = 0;
    }
    sqlite4CodeSubselect(pParse, pX, rMayHaveNull);
    pParse->nQueryLoop = savedNQueryLoop;
  }else{
    pX->iTable = iTab;
  }
  return eType;
}
#endif
................................................................................
** For a SELECT or EXISTS operator, return the register that holds the
** result.  For IN operators or if an error occurs, the return value is 0.
*/
#ifndef SQLITE4_OMIT_SUBQUERY
int sqlite4CodeSubselect(
  Parse *pParse,          /* Parsing context */
  Expr *pExpr,            /* The IN, SELECT, or EXISTS operator */
  int rMayHaveNull        /* Register that records whether NULLs exist in RHS */

){
  int testAddr = -1;                      /* One-time test address */
  int rReg = 0;                           /* Register storing resulting */
  Vdbe *v = sqlite4GetVdbe(pParse);
  if( NEVER(v==0) ) return 0;
  sqlite4ExprCachePush(pParse);

................................................................................
      ** column is used to build the index keys. If both 'x' and the
      ** SELECT... statement are columns, then numeric affinity is used
      ** if either column has NUMERIC or INTEGER affinity. If neither
      ** 'x' nor the SELECT... statement are columns, then numeric affinity
      ** is used.
      */
      pExpr->iTable = pParse->nTab++;
      addr = sqlite4VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, 1);
      memset(&keyInfo, 0, sizeof(keyInfo));
      keyInfo.nField = 1;

      if( ExprHasProperty(pExpr, EP_xIsSelect) ){
        /* Case 1:     expr IN (SELECT ...)
        **
        ** Generate code to write the results of the select into the temporary
        ** table allocated and opened above.
        */
        SelectDest dest;
        ExprList *pEList;


        sqlite4SelectDestInit(&dest, SRT_Set, pExpr->iTable);
        dest.affinity = (u8)affinity;
        assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
        pExpr->x.pSelect->iLimit = 0;
        if( sqlite4Select(pParse, pExpr->x.pSelect, &dest) ){
          return 0;
        }
................................................................................
        ** store it in the temporary table. If <expr> is a column, then use
        ** that columns affinity when building index keys. If <expr> is not
        ** a column, use numeric affinity.
        */
        int i;
        ExprList *pList = pExpr->x.pList;
        ExprListItem *pItem;
        int r1, r2, r3, r4;

        if( !affinity ){
          affinity = SQLITE4_AFF_NONE;
        }
        keyInfo.aColl[0] = sqlite4ExprCollSeq(pParse, pExpr->pLeft);

        /* Loop through each expression in <exprlist>. */
................................................................................
          */
          if( testAddr>=0 && !sqlite4ExprIsConstant(pE2) ){
            sqlite4VdbeChangeToNoop(v, testAddr);
            testAddr = -1;
          }

          /* Evaluate the expression and insert it into the temp table */



          r3 = sqlite4ExprCodeTarget(pParse, pE2, r1);





          r4 = sqlite4GetTempReg(pParse);
          sqlite4VdbeAddOp2(v, OP_MakeKey, pExpr->iTable, r4);
          sqlite4VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1);
          sqlite4ExprCacheAffinityChange(pParse, r3, 1);
          sqlite4VdbeAddOp3(v, OP_IdxInsert, pExpr->iTable, r2, r4);
          sqlite4ReleaseTempReg(pParse, r4);


        }
        sqlite4ReleaseTempReg(pParse, r1);
        sqlite4ReleaseTempReg(pParse, r2);
      }

      sqlite4VdbeChangeP4(v, addr, (void *)&keyInfo, P4_KEYINFO);

      break;
    }

    case TK_EXISTS:
    case TK_SELECT:
    default: {
      /* If this has to be a scalar SELECT.  Generate code to put the
................................................................................
      break;
    }
#ifndef SQLITE4_OMIT_SUBQUERY
    case TK_EXISTS:
    case TK_SELECT: {
      testcase( op==TK_EXISTS );
      testcase( op==TK_SELECT );
      inReg = sqlite4CodeSubselect(pParse, pExpr, 0);
      break;
    }
    case TK_IN: {
      int destIfFalse = sqlite4VdbeMakeLabel(v);
      int destIfNull = sqlite4VdbeMakeLabel(v);
      sqlite4VdbeAddOp2(v, OP_Null, 0, target);
      sqlite4ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);

#endif
void sqlite4Reindex(Parse*, Token*, Token*);
void sqlite4AlterFunctions(sqlite4_env*);
void sqlite4AlterRenameTable(Parse*, SrcList*, Token*);
int sqlite4GetToken(const unsigned char *, int *);
void sqlite4NestedParse(Parse*, const char*, ...);
void sqlite4ExpirePreparedStatements(sqlite4*);
int sqlite4CodeSubselect(Parse *, Expr *, int, int);
void sqlite4SelectPrep(Parse*, Select*, NameContext*);
int sqlite4ResolveExprNames(NameContext*, Expr*);
void sqlite4ResolveSelectNames(Parse*, Select*, NameContext*);
int sqlite4ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
void sqlite4ColumnDefault(Vdbe *, Table *, int, int);
void sqlite4AlterFinishAddColumn(Parse *, Token *);
void sqlite4AlterBeginAddColumn(Parse *, SrcList *);

#endif
void sqlite4Reindex(Parse*, Token*, Token*);
void sqlite4AlterFunctions(sqlite4_env*);
void sqlite4AlterRenameTable(Parse*, SrcList*, Token*);
int sqlite4GetToken(const unsigned char *, int *);
void sqlite4NestedParse(Parse*, const char*, ...);
void sqlite4ExpirePreparedStatements(sqlite4*);
int sqlite4CodeSubselect(Parse *, Expr *, int);
void sqlite4SelectPrep(Parse*, Select*, NameContext*);
int sqlite4ResolveExprNames(NameContext*, Expr*);
void sqlite4ResolveSelectNames(Parse*, Select*, NameContext*);
int sqlite4ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
void sqlite4ColumnDefault(Vdbe *, Table *, int, int);
void sqlite4AlterFinishAddColumn(Parse *, Token *);
void sqlite4AlterBeginAddColumn(Parse *, SrcList *);

** and register P2 becomes ephemeral.  If the cursor is changed, the
** value of register P2 will then change.  Make sure this does not
** cause any problems.)
**
** This instruction only works on tables.  The equivalent instruction
** for indices is OP_IdxInsert.
*/
/* Opcode: InsertInt P1 P2 P3 P4 P5
**
** This works exactly like OP_Insert except that the key is the
** integer value P3, not the value of the integer stored in register P3.
*/
case OP_Insert:
case OP_InsertInt: {
  Mem *pData;       /* MEM cell holding data for the record to be inserted */
  Mem *pKey;        /* MEM cell holding key  for the record */
  i64 iKey;         /* The integer ROWID or key for the record to be inserted */
  VdbeCursor *pC;   /* Cursor to table into which insert is written */
  int n;
  KVByteArray aKey[24];

................................................................................
  pData = &aMem[pOp->p2];
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( memIsValid(pData) );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  REGISTER_TRACE(pOp->p2, pData);

  if( pOp->opcode==OP_Insert ){
    pKey = &aMem[pOp->p3];
    assert( pKey->flags & MEM_Int );
    assert( memIsValid(pKey) );
    REGISTER_TRACE(pOp->p3, pKey);
    iKey = sqlite4_num_to_int64(pKey->u.num, 0);
  }else{
    /* assert( pOp->opcode==OP_InsertInt ); */
    iKey = pOp->p3;
  }

  if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;
  if( pData->flags & MEM_Null ){
    pData->z = 0;
    pData->n = 0;
  }else{
    assert( pData->flags & (MEM_Blob|MEM_Str) );

** and register P2 becomes ephemeral.  If the cursor is changed, the
** value of register P2 will then change.  Make sure this does not
** cause any problems.)
**
** This instruction only works on tables.  The equivalent instruction
** for indices is OP_IdxInsert.
*/





case OP_Insert: {

  Mem *pData;       /* MEM cell holding data for the record to be inserted */
  Mem *pKey;        /* MEM cell holding key  for the record */
  i64 iKey;         /* The integer ROWID or key for the record to be inserted */
  VdbeCursor *pC;   /* Cursor to table into which insert is written */
  int n;
  KVByteArray aKey[24];

................................................................................
  pData = &aMem[pOp->p2];
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( memIsValid(pData) );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  REGISTER_TRACE(pOp->p2, pData);


  pKey = &aMem[pOp->p3];
  assert( pKey->flags & MEM_Int );
  assert( memIsValid(pKey) );
  REGISTER_TRACE(pOp->p3, pKey);
  iKey = sqlite4_num_to_int64(pKey->u.num, 0);





  if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;
  if( pData->flags & MEM_Null ){
    pData->z = 0;
    pData->n = 0;
  }else{
    assert( pData->flags & (MEM_Blob|MEM_Str) );