src/insert.c - master - clang/sqlite

src/insert.c
3 483 строки130 KB
dan
After a DELETE trigger is fired by REPLACE conflict handling, retest all UNIQUE constraints to ensure that the row being inserted or updated does not conflict with one written by the DELETE trigger. Abort the statement if it does. Possible fix for forum post [forum:/info/2026-07-18T03:35:48Z | 2026-07-18T03:35:48Z].
18 июл 2026, 22:31
18 июл 2026, 22:31c1c108f
/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle INSERT statements in SQLite.
*/
#include "sqliteInt.h"

/*
** Generate code that will
**
**   (1) acquire a lock for table pTab then
**   (2) open pTab as cursor iCur.
**
** If pTab is a WITHOUT ROWID table, then it is the PRIMARY KEY index
** for that table that is actually opened.
*/
void sqlite3OpenTable(
  Parse *pParse,  /* Generate code into this VDBE */
  int iCur,       /* The cursor number of the table */
  int iDb,        /* The database index in sqlite3.aDb[] */
  Table *pTab,    /* The table to be opened */
  int opcode      /* OP_OpenRead or OP_OpenWrite */
){
  Vdbe *v;
  assert( !IsVirtual(pTab) );
  assert( pParse->pVdbe!=0 );
  v = pParse->pVdbe;
  assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );
  if( !pParse->db->noSharedCache ){
    sqlite3TableLock(pParse, iDb, pTab->tnum,
                     (opcode==OP_OpenWrite)?1:0, pTab->zName);
  }
  if( HasRowid(pTab) ){
    sqlite3VdbeAddOp4Int(v, opcode, iCur, pTab->tnum, iDb, pTab->nNVCol);
    VdbeComment((v, "%s", pTab->zName));
  }else{
    Index *pPk = sqlite3PrimaryKeyIndex(pTab);
    assert( pPk!=0 );
    assert( pPk->tnum==pTab->tnum || CORRUPT_DB );
    sqlite3VdbeAddOp3(v, opcode, iCur, pPk->tnum, iDb);
    sqlite3VdbeSetP4KeyInfo(pParse, pPk);
    VdbeComment((v, "%s", pTab->zName));
  }
}

/*
** Return a pointer to the column affinity string associated with index
** pIdx. A column affinity string has one character for each column in
** the table, according to the affinity of the column:
**
**  Character      Column affinity
**  ------------------------------
**  'A'            BLOB
**  'B'            TEXT
**  'C'            NUMERIC
**  'D'            INTEGER
**  'F'            REAL
**
** An extra 'D' is appended to the end of the string to cover the
** rowid that appears as the last column in every index.
**
** Memory for the buffer containing the column index affinity string
** is managed along with the rest of the Index structure. It will be
** released when sqlite3DeleteIndex() is called.
*/
static SQLITE_NOINLINE const char *computeIndexAffStr(sqlite3 *db, Index *pIdx){
  /* The first time a column affinity string for a particular index is
  ** required, it is allocated and populated here. It is then stored as
  ** a member of the Index structure for subsequent use.
  **
  ** The column affinity string will eventually be deleted by
  ** sqliteDeleteIndex() when the Index structure itself is cleaned
  ** up.
  */
  int n;
  Table *pTab = pIdx->pTable;
  pIdx->zColAff = (char *)sqlite3DbMallocRaw(0, pIdx->nColumn+1);
  if( !pIdx->zColAff ){
    sqlite3OomFault(db);
    return 0;
  }
  for(n=0; n<pIdx->nColumn; n++){
    i16 x = pIdx->aiColumn[n];
    char aff;
    if( x>=0 ){
      aff = pTab->aCol[x].affinity;
    }else if( x==XN_ROWID ){
      aff = SQLITE_AFF_INTEGER;
    }else{
      assert( x==XN_EXPR );
      assert( pIdx->bHasExpr );
      assert( pIdx->aColExpr!=0 );
      aff = sqlite3ExprAffinity(pIdx->aColExpr->a[n].pExpr);
    }
    if( aff<SQLITE_AFF_BLOB ) aff = SQLITE_AFF_BLOB;
    if( aff>SQLITE_AFF_NUMERIC) aff = SQLITE_AFF_NUMERIC;
    pIdx->zColAff[n] = aff;
  }
  pIdx->zColAff[n] = 0;
  return pIdx->zColAff;
}
const char *sqlite3IndexAffinityStr(sqlite3 *db, Index *pIdx){
  if( !pIdx->zColAff ) return computeIndexAffStr(db, pIdx);
  return pIdx->zColAff;
}


/*
** Compute an affinity string for a table.   Space is obtained
** from sqlite3DbMalloc().  The caller is responsible for freeing
** the space when done.
*/
char *sqlite3TableAffinityStr(sqlite3 *db, const Table *pTab){
  char *zColAff;
  zColAff = (char *)sqlite3DbMallocRaw(db, pTab->nCol+1);
  if( zColAff ){
    int i, j;
    for(i=j=0; i<pTab->nCol; i++){
      if( (pTab->aCol[i].colFlags & COLFLAG_VIRTUAL)==0 ){
        zColAff[j++] = pTab->aCol[i].affinity;
      }
    }
    do{
      zColAff[j--] = 0;
    }while( j>=0 && zColAff[j]<=SQLITE_AFF_BLOB );
  }
  return zColAff; 
}

/*
** Make changes to the evolving bytecode to do affinity transformations
** of values that are about to be gathered into a row for table pTab.
**
** For ordinary (legacy, non-strict) tables:
** -----------------------------------------
**
** Compute the affinity string for table pTab, if it has not already been
** computed.  As an optimization, omit trailing SQLITE_AFF_BLOB affinities.
**
** If the affinity string is empty (because it was all SQLITE_AFF_BLOB entries
** which were then optimized out) then this routine becomes a no-op.
**
** Otherwise if iReg>0 then code an OP_Affinity opcode that will set the
** affinities for register iReg and following.  Or if iReg==0,
** then just set the P4 operand of the previous opcode (which should  be
** an OP_MakeRecord) to the affinity string.
**
** A column affinity string has one character per column:
**
**    Character      Column affinity
**    ---------      ---------------
**    'A'            BLOB
**    'B'            TEXT
**    'C'            NUMERIC
**    'D'            INTEGER
**    'E'            REAL
**
** For STRICT tables:
** ------------------
**
** Generate an appropriate OP_TypeCheck opcode that will verify the
** datatypes against the column definitions in pTab.  If iReg==0, that
** means an OP_MakeRecord opcode has already been generated and should be
** the last opcode generated.  The new OP_TypeCheck needs to be inserted
** before the OP_MakeRecord.  The new OP_TypeCheck should use the same
** register set as the OP_MakeRecord.  If iReg>0 then register iReg is
** the first of a series of registers that will form the new record.
** Apply the type checking to that array of registers.
*/
void sqlite3TableAffinity(Vdbe *v, Table *pTab, int iReg){
  int i;
  char *zColAff;
  if( pTab->tabFlags & TF_Strict ){
    if( iReg==0 ){
      /* Move the previous opcode (which should be OP_MakeRecord) forward
      ** by one slot and insert a new OP_TypeCheck where the current
      ** OP_MakeRecord is found */
      VdbeOp *pPrev;
      int p3;
      sqlite3VdbeAppendP4(v, pTab, P4_TABLE);
      pPrev = sqlite3VdbeGetLastOp(v);
      assert( pPrev!=0 );
      assert( pPrev->opcode==OP_MakeRecord || sqlite3VdbeDb(v)->mallocFailed );
      pPrev->opcode = OP_TypeCheck;
      p3 = pPrev->p3;
      pPrev->p3 = 0;
      sqlite3VdbeAddOp3(v, OP_MakeRecord, pPrev->p1, pPrev->p2, p3);
    }else{
      /* Insert an isolated OP_Typecheck */
      sqlite3VdbeAddOp2(v, OP_TypeCheck, iReg, pTab->nNVCol);
      sqlite3VdbeAppendP4(v, pTab, P4_TABLE);
    }
    return;
  }
  zColAff = pTab->zColAff;
  if( zColAff==0 ){
    zColAff = sqlite3TableAffinityStr(0, pTab);
    if( !zColAff ){
      sqlite3OomFault(sqlite3VdbeDb(v));
      return;
    }
    pTab->zColAff = zColAff;
  }
  assert( zColAff!=0 );
  i = sqlite3Strlen30NN(zColAff);
  if( i ){
    if( iReg ){
      sqlite3VdbeAddOp4(v, OP_Affinity, iReg, i, 0, zColAff, i);
    }else{
      assert( sqlite3VdbeGetLastOp(v)->opcode==OP_MakeRecord
              || sqlite3VdbeDb(v)->mallocFailed );
      sqlite3VdbeChangeP4(v, -1, zColAff, i);
    }
  }
}

/*
** Return non-zero if the table pTab in database iDb or any of its indices
** have been opened at any point in the VDBE program. This is used to see if
** a statement of the form  "INSERT INTO <iDb, pTab> SELECT ..." can
** run without using a temporary table for the results of the SELECT.
*/
static int readsTable(Parse *p, int iDb, Table *pTab){
  Vdbe *v = sqlite3GetVdbe(p);
  int i;
  int iEnd = sqlite3VdbeCurrentAddr(v);
#ifndef SQLITE_OMIT_VIRTUALTABLE
  VTable *pVTab = IsVirtual(pTab) ? sqlite3GetVTable(p->db, pTab) : 0;
#endif

  for(i=1; i<iEnd; i++){
    VdbeOp *pOp = sqlite3VdbeGetOp(v, i);
    assert( pOp!=0 );
    if( pOp->opcode==OP_OpenRead && pOp->p3==iDb ){
      Index *pIndex;
      Pgno tnum = pOp->p2;
      if( tnum==pTab->tnum ){
        return 1;
      }
      for(pIndex=pTab->pIndex; pIndex; pIndex=pIndex->pNext){
        if( tnum==pIndex->tnum ){
          return 1;
        }
      }
    }
#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( pOp->opcode==OP_VOpen && pOp->p4.pVtab==pVTab ){
      assert( pOp->p4.pVtab!=0 );
      assert( pOp->p4type==P4_VTAB );
      return 1;
    }
#endif
  }
  return 0;
}

/* This walker callback will compute the union of colFlags flags for all
** referenced columns in a CHECK constraint or generated column expression.
*/
static int exprColumnFlagUnion(Walker *pWalker, Expr *pExpr){
  if( pExpr->op==TK_COLUMN && pExpr->iColumn>=0 ){
    assert( pExpr->iColumn < pWalker->u.pTab->nCol );
    pWalker->eCode |= pWalker->u.pTab->aCol[pExpr->iColumn].colFlags;
  }
  return WRC_Continue;
}

#ifndef SQLITE_OMIT_GENERATED_COLUMNS
/*
** All regular columns for table pTab have been puts into registers
** starting with iRegStore.  The registers that correspond to STORED
** or VIRTUAL columns have not yet been initialized.  This routine goes
** back and computes the values for those columns based on the previously
** computed normal columns.
*/
void sqlite3ComputeGeneratedColumns(
  Parse *pParse,    /* Parsing context */
  int iRegStore,    /* Register holding the first column */
  Table *pTab       /* The table */
){
  int i;
  Walker w;
  Column *pRedo;
  int eProgress;
  VdbeOp *pOp;

  assert( pTab->tabFlags & TF_HasGenerated );
  testcase( pTab->tabFlags & TF_HasVirtual );
  testcase( pTab->tabFlags & TF_HasStored );

  /* Before computing generated columns, first go through and make sure
  ** that appropriate affinity has been applied to the regular columns
  */
  sqlite3TableAffinity(pParse->pVdbe, pTab, iRegStore);
  if( (pTab->tabFlags & TF_HasStored)!=0 ){
    pOp = sqlite3VdbeGetLastOp(pParse->pVdbe);
    if( pOp->opcode==OP_Affinity ){
      /* Change the OP_Affinity argument to '@' (NONE) for all stored
      ** columns.  '@' is the no-op affinity and those columns have not
      ** yet been computed. */
      int ii, jj;
      char *zP4 = pOp->p4.z;
      assert( zP4!=0 );
      assert( pOp->p4type==P4_DYNAMIC );
      for(ii=jj=0; zP4[jj]; ii++){
        if( pTab->aCol[ii].colFlags & COLFLAG_VIRTUAL ){
          continue;
        }
        if( pTab->aCol[ii].colFlags & COLFLAG_STORED ){
          zP4[jj] = SQLITE_AFF_NONE;
        }
        jj++;
      }
    }else if( pOp->opcode==OP_TypeCheck ){
      /* If an OP_TypeCheck was generated because the table is STRICT,
      ** then set the P3 operand to indicate that generated columns should
      ** not be checked */
      pOp->p3 = 1;
    }
  }

  /* Because there can be multiple generated columns that refer to one another,
  ** this is a two-pass algorithm.  On the first pass, mark all generated
  ** columns as "not available".
  */
  for(i=0; i<pTab->nCol; i++){
    if( pTab->aCol[i].colFlags & COLFLAG_GENERATED ){
      testcase( pTab->aCol[i].colFlags & COLFLAG_VIRTUAL );
      testcase( pTab->aCol[i].colFlags & COLFLAG_STORED );
      pTab->aCol[i].colFlags |= COLFLAG_NOTAVAIL;
    }
  }

  w.u.pTab = pTab;
  w.xExprCallback = exprColumnFlagUnion;
  w.xSelectCallback = 0;
  w.xSelectCallback2 = 0;

  /* On the second pass, compute the value of each NOT-AVAILABLE column.
  ** Companion code in the TK_COLUMN case of sqlite3ExprCodeTarget() will
  ** compute dependencies and mark remove the COLSPAN_NOTAVAIL mark, as
  ** they are needed.
  */
  pParse->iSelfTab = -iRegStore;
  do{
    eProgress = 0;
    pRedo = 0;
    for(i=0; i<pTab->nCol; i++){
      Column *pCol = pTab->aCol + i;
      if( (pCol->colFlags & COLFLAG_NOTAVAIL)!=0 ){
        int x;
        pCol->colFlags |= COLFLAG_BUSY;
        w.eCode = 0;
        sqlite3WalkExpr(&w, sqlite3ColumnExpr(pTab, pCol));
        pCol->colFlags &= ~COLFLAG_BUSY;
        if( w.eCode & COLFLAG_NOTAVAIL ){
          pRedo = pCol;
          continue;
        }
        eProgress = 1;
        assert( pCol->colFlags & COLFLAG_GENERATED );
        x = sqlite3TableColumnToStorage(pTab, i) + iRegStore;
        sqlite3ExprCodeGeneratedColumn(pParse, pTab, pCol, x);
        pCol->colFlags &= ~COLFLAG_NOTAVAIL;
      }
    }
  }while( pRedo && eProgress );
  if( pRedo ){
    sqlite3ErrorMsg(pParse, "generated column loop on \"%s\"", pRedo->zCnName);
  }
  pParse->iSelfTab = 0;
}
#endif /* SQLITE_OMIT_GENERATED_COLUMNS */


#ifndef SQLITE_OMIT_AUTOINCREMENT
/*
** Locate or create an AutoincInfo structure associated with table pTab
** which is in database iDb.  Return the register number for the register
** that holds the maximum rowid.  Return zero if pTab is not an AUTOINCREMENT
** table.  (Also return zero when doing a VACUUM since we do not want to
** update the AUTOINCREMENT counters during a VACUUM.)
**
** There is at most one AutoincInfo structure per table even if the
** same table is autoincremented multiple times due to inserts within
** triggers.  A new AutoincInfo structure is created if this is the
** first use of table pTab.  On 2nd and subsequent uses, the original
** AutoincInfo structure is used.
**
** Four consecutive registers are allocated:
**
**   (1)  The name of the pTab table.
**   (2)  The maximum ROWID of pTab.
**   (3)  The rowid in sqlite_sequence of pTab
**   (4)  The original value of the max ROWID in pTab, or NULL if none
**
** The 2nd register is the one that is returned.  That is all the
** insert routine needs to know about.
*/
static int autoIncBegin(
  Parse *pParse,      /* Parsing context */
  int iDb,            /* Index of the database holding pTab */
  Table *pTab         /* The table we are writing to */
){
  int memId = 0;      /* Register holding maximum rowid */
  assert( pParse->db->aDb[iDb].pSchema!=0 );
  if( (pTab->tabFlags & TF_Autoincrement)!=0
   && (pParse->db->mDbFlags & DBFLAG_Vacuum)==0
  ){
    Parse *pToplevel = sqlite3ParseToplevel(pParse);
    AutoincInfo *pInfo;
    Table *pSeqTab = pParse->db->aDb[iDb].pSchema->pSeqTab;

    /* Verify that the sqlite_sequence table exists and is an ordinary
    ** rowid table with exactly two columns.
    ** Ticket d8dc2b3a58cd5dc2918a1d4acb 2018-05-23 */
    if( pSeqTab==0
     || !HasRowid(pSeqTab)
     || NEVER(IsVirtual(pSeqTab))
     || pSeqTab->nCol!=2
    ){
      pParse->nErr++;
      pParse->rc = SQLITE_CORRUPT_SEQUENCE;
      return 0;
    }

    if( pToplevel->usesAinc==0 ){
      pToplevel->pAinc = 0;
    }
    pInfo = pToplevel->pAinc;
    while( pInfo && pInfo->pTab!=pTab ){ pInfo = pInfo->pNext; }
    if( pInfo==0 ){
      pInfo = sqlite3DbMallocRawNN(pParse->db, sizeof(*pInfo));
      sqlite3ParserAddCleanup(pToplevel, sqlite3DbFree, pInfo);
      testcase( pParse->earlyCleanup );
      if( pParse->db->mallocFailed ) return 0;
      pInfo->pNext = pToplevel->pAinc;
      pToplevel->pAinc = pInfo;
      pToplevel->usesAinc = 1;
      pInfo->pTab = pTab;
      pInfo->iDb = iDb;
      pToplevel->nMem++;                  /* Register to hold name of table */
      pInfo->regCtr = ++pToplevel->nMem;  /* Max rowid register */
      pToplevel->nMem +=2;       /* Rowid in sqlite_sequence + orig max val */
    }
    memId = pInfo->regCtr;
  }
  return memId;
}

/*
** This routine generates code that will initialize all of the
** register used by the autoincrement tracker. 
*/
void sqlite3AutoincrementBegin(Parse *pParse){
  AutoincInfo *p;            /* Information about an AUTOINCREMENT */
  sqlite3 *db = pParse->db;  /* The database connection */
  Db *pDb;                   /* Database only autoinc table */
  int memId;                 /* Register holding max rowid */
  Vdbe *v = pParse->pVdbe;   /* VDBE under construction */

  /* This routine is never called during trigger-generation.  It is
  ** only called from the top-level */
  assert( pParse->pTriggerTab==0 );
  assert( sqlite3IsToplevel(pParse) );

  assert( v );   /* We failed long ago if this is not so */
  assert( pParse->usesAinc );
  for(p = pParse->pAinc; p; p = p->pNext){
    static const int iLn = VDBE_OFFSET_LINENO(2);
    static const VdbeOpList autoInc[] = {
      /* 0  */ {OP_Null,    0,  0, 0},
      /* 1  */ {OP_Rewind,  0, 10, 0},
      /* 2  */ {OP_Column,  0,  0, 0},
      /* 3  */ {OP_Ne,      0,  9, 0},
      /* 4  */ {OP_Rowid,   0,  0, 0},
      /* 5  */ {OP_Column,  0,  1, 0},
      /* 6  */ {OP_AddImm,  0,  0, 0},
      /* 7  */ {OP_Copy,    0,  0, 0},
      /* 8  */ {OP_Goto,    0, 11, 0},
      /* 9  */ {OP_Next,    0,  2, 0},
      /* 10 */ {OP_Integer, 0,  0, 0},
      /* 11 */ {OP_Close,   0,  0, 0}
    };
    VdbeOp *aOp;
    pDb = &db->aDb[p->iDb];
    memId = p->regCtr;
    assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );
    sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenRead);
    sqlite3VdbeLoadString(v, memId-1, p->pTab->zName);
    aOp = sqlite3VdbeAddOpList(v, ArraySize(autoInc), autoInc, iLn);
    if( aOp==0 ) break;
    aOp[0].p2 = memId;
    aOp[0].p3 = memId+2;
    aOp[2].p3 = memId;
    aOp[3].p1 = memId-1;
    aOp[3].p3 = memId;
    aOp[3].p5 = SQLITE_JUMPIFNULL;
    aOp[4].p2 = memId+1;
    aOp[5].p3 = memId;
    aOp[6].p1 = memId;
    aOp[7].p2 = memId+2;
    aOp[7].p1 = memId;
    aOp[10].p2 = memId;
    if( pParse->nTab==0 ) pParse->nTab = 1;
  }
}

/*
** Update the maximum rowid for an autoincrement calculation.
**
** This routine should be called when the regRowid register holds a
** new rowid that is about to be inserted.  If that new rowid is
** larger than the maximum rowid in the memId memory cell, then the
** memory cell is updated.
*/
static void autoIncStep(Parse *pParse, int memId, int regRowid){
  if( memId>0 ){
    sqlite3VdbeAddOp2(pParse->pVdbe, OP_MemMax, memId, regRowid);
  }
}

/*
** This routine generates the code needed to write autoincrement
** maximum rowid values back into the sqlite_sequence register.
** Every statement that might do an INSERT into an autoincrement
** table (either directly or through triggers) needs to call this
** routine just before the "exit" code.
*/
static SQLITE_NOINLINE void autoIncrementEnd(Parse *pParse){
  AutoincInfo *p;
  Vdbe *v = pParse->pVdbe;
  sqlite3 *db = pParse->db;

  assert( v );
  assert( pParse->usesAinc );
  for(p = pParse->pAinc; p; p = p->pNext){
    static const int iLn = VDBE_OFFSET_LINENO(2);
    static const VdbeOpList autoIncEnd[] = {
      /* 0 */ {OP_NotNull,     0, 2, 0},
      /* 1 */ {OP_NewRowid,    0, 0, 0},
      /* 2 */ {OP_MakeRecord,  0, 2, 0},
      /* 3 */ {OP_Insert,      0, 0, 0},
      /* 4 */ {OP_Close,       0, 0, 0}
    };
    VdbeOp *aOp;
    Db *pDb = &db->aDb[p->iDb];
    int iRec;
    int memId = p->regCtr;

    iRec = sqlite3GetTempReg(pParse);
    assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );
    sqlite3VdbeAddOp3(v, OP_Le, memId+2, sqlite3VdbeCurrentAddr(v)+7, memId);
    VdbeCoverage(v);
    sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenWrite);
    aOp = sqlite3VdbeAddOpList(v, ArraySize(autoIncEnd), autoIncEnd, iLn);
    if( aOp==0 ) break;
    aOp[0].p1 = memId+1;
    aOp[1].p2 = memId+1;
    aOp[2].p1 = memId-1;
    aOp[2].p3 = iRec;
    aOp[3].p2 = iRec;
    aOp[3].p3 = memId+1;
    aOp[3].p5 = OPFLAG_APPEND;
    sqlite3ReleaseTempReg(pParse, iRec);
  }
}
void sqlite3AutoincrementEnd(Parse *pParse){
  if( pParse->usesAinc ) autoIncrementEnd(pParse);
}
#else
/*
** If SQLITE_OMIT_AUTOINCREMENT is defined, then the three routines
** above are all no-ops
*/
# define autoIncBegin(A,B,C) (0)
# define autoIncStep(A,B,C)
#endif /* SQLITE_OMIT_AUTOINCREMENT */

/*
** If argument pVal is a Select object returned by an sqlite3MultiValues()
** that was able to use the co-routine optimization, finish coding the
** co-routine.
*/
void sqlite3MultiValuesEnd(Parse *pParse, Select *pVal){
  if( ALWAYS(pVal) && pVal->pSrc->nSrc>0 ){
    SrcItem *pItem = &pVal->pSrc->a[0];
    assert( (pItem->fg.isSubquery && pItem->u4.pSubq!=0) || pParse->nErr );
    if( pItem->fg.isSubquery ){
      sqlite3VdbeEndCoroutine(pParse->pVdbe, pItem->u4.pSubq->regReturn);
      sqlite3VdbeJumpHere(pParse->pVdbe, pItem->u4.pSubq->addrFillSub - 1);
    }
  }
}

/*
** Return true if all expressions in the expression-list passed as the
** only argument are constant.
*/
static int exprListIsConstant(Parse *pParse, ExprList *pRow){
  int ii;
  for(ii=0; ii<pRow->nExpr; ii++){
    if( 0==sqlite3ExprIsConstant(pParse, pRow->a[ii].pExpr) ) return 0;
  }
  return 1;
}

/*
** Return true if all expressions in the expression-list passed as the
** only argument are both constant and have no affinity.
*/
static int exprListIsNoAffinity(Parse *pParse, ExprList *pRow){
  int ii;
  if( exprListIsConstant(pParse,pRow)==0 ) return 0;
  for(ii=0; ii<pRow->nExpr; ii++){
    Expr *pExpr = pRow->a[ii].pExpr;
    assert( pExpr->op!=TK_RAISE );
    assert( pExpr->affExpr==0 );
    if( 0!=sqlite3ExprAffinity(pExpr) ) return 0;
  }
  return 1;

}

/*
** This function is called by the parser for the second and subsequent
** rows of a multi-row VALUES clause. Argument pLeft is the part of
** the VALUES clause already parsed, argument pRow is the vector of values
** for the new row. The Select object returned represents the complete
** VALUES clause, including the new row.
**
** There are two ways in which this may be achieved - by incremental 
** coding of a co-routine (the "co-routine" method) or by returning a
** Select object equivalent to the following (the "UNION ALL" method):
**
**        "pLeft UNION ALL SELECT pRow"
**
** If the VALUES clause contains a lot of rows, this compound Select
** object may consume a lot of memory.
**
** When the co-routine method is used, each row that will be returned
** by the VALUES clause is coded into part of a co-routine as it is 
** passed to this function. The returned Select object is equivalent to:
**
**     SELECT * FROM (
**       Select object to read co-routine
**     )
**
** The co-routine method is used in most cases. Exceptions are:
**
**    a) If the current statement has a WITH clause. This is to avoid
**       statements like:
**
**            WITH cte AS ( VALUES('x'), ('y') ... )
**            SELECT * FROM cte AS a, cte AS b;
**
**       This will not work, as the co-routine uses a hard-coded register
**       for its OP_Yield instructions, and so it is not possible for two
**       cursors to iterate through it concurrently.
**
**    b) The schema is currently being parsed (i.e. the VALUES clause is part 
**       of a schema item like a VIEW or TRIGGER). In this case there is no VM
**       being generated when parsing is taking place, and so generating 
**       a co-routine is not possible.
**
**    c) There are non-constant expressions in the VALUES clause (e.g.
**       the VALUES clause is part of a correlated sub-query).
**
**    d) One or more of the values in the first row of the VALUES clause
**       has an affinity (i.e. is a CAST expression). This causes problems
**       because the complex rules SQLite uses (see function 
**       sqlite3SubqueryColumnTypes() in select.c) to determine the effective
**       affinity of such a column for all rows require access to all values in
**       the column simultaneously. 
*/
Select *sqlite3MultiValues(Parse *pParse, Select *pLeft, ExprList *pRow){

  if( pParse->bHasWith                   /* condition (a) above */
   || pParse->db->init.busy              /* condition (b) above */
   || exprListIsConstant(pParse,pRow)==0 /* condition (c) above */
   || (pLeft->pSrc->nSrc==0 &&
       exprListIsNoAffinity(pParse,pLeft->pEList)==0) /* condition (d) above */
   || IN_SPECIAL_PARSE
  ){
    /* The co-routine method cannot be used. Fall back to UNION ALL. */
    Select *pSelect = 0;
    int f = SF_Values | SF_MultiValue;
    if( pLeft->pSrc->nSrc ){
      sqlite3MultiValuesEnd(pParse, pLeft);
      f = SF_Values;
    }else if( pLeft->pPrior ){
      /* In this case set the SF_MultiValue flag only if it was set on pLeft */
      f = (f & pLeft->selFlags);
    }
    pSelect = sqlite3SelectNew(pParse, pRow, 0, 0, 0, 0, 0, f, 0);
    pLeft->selFlags &= ~(u32)SF_MultiValue;
    if( pSelect ){
      pSelect->op = TK_ALL;
      pSelect->pPrior = pLeft;
      pLeft = pSelect;
    }
  }else{
    SrcItem *p = 0;               /* SrcItem that reads from co-routine */

    if( pLeft->pSrc->nSrc==0 ){
      /* Co-routine has not yet been started and the special Select object
      ** that accesses the co-routine has not yet been created. This block 
      ** does both those things. */
      Vdbe *v = sqlite3GetVdbe(pParse);
      Select *pRet = sqlite3SelectNew(pParse, 0, 0, 0, 0, 0, 0, 0, 0);

      /* Ensure the database schema has been read. This is to ensure we have
      ** the correct text encoding.  */
      if( (pParse->db->mDbFlags & DBFLAG_SchemaKnownOk)==0 ){
        sqlite3ReadSchema(pParse);
      }

      if( pRet ){
        SelectDest dest;
        Subquery *pSubq;
        pRet->pSrc->nSrc = 1;
        pRet->pPrior = pLeft->pPrior;
        pRet->op = pLeft->op;
        if( pRet->pPrior ) pRet->selFlags |= SF_Values;
        pLeft->pPrior = 0;
        pLeft->op = TK_SELECT;
        assert( pLeft->pNext==0 );
        assert( pRet->pNext==0 );
        p = &pRet->pSrc->a[0];
        p->fg.viaCoroutine = 1;
        p->iCursor = -1;
        assert( !p->fg.isIndexedBy && !p->fg.isTabFunc );
        p->u1.nRow = 2;
        if( sqlite3SrcItemAttachSubquery(pParse, p, pLeft, 0) ){
          pSubq = p->u4.pSubq;
          pSubq->addrFillSub = sqlite3VdbeCurrentAddr(v) + 1;
          pSubq->regReturn = ++pParse->nMem;
          sqlite3VdbeAddOp3(v, OP_InitCoroutine,
                            pSubq->regReturn, 0, pSubq->addrFillSub);
          sqlite3SelectDestInit(&dest, SRT_Coroutine, pSubq->regReturn);

          /* Allocate registers for the output of the co-routine. Do so so
          ** that there are two unused registers immediately before those
          ** used by the co-routine. This allows the code in sqlite3Insert()
          ** to use these registers directly, instead of copying the output
          ** of the co-routine to a separate array for processing.  */
          dest.iSdst = pParse->nMem + 3; 
          dest.nSdst = pLeft->pEList->nExpr;
          pParse->nMem += 2 + dest.nSdst;

          pLeft->selFlags |= SF_MultiValue;
          sqlite3Select(pParse, pLeft, &dest);
          pSubq->regResult = dest.iSdst;
          assert( pParse->nErr || dest.iSdst>0 );
        }
        pLeft = pRet;
      }
    }else{
      p = &pLeft->pSrc->a[0];
      assert( !p->fg.isTabFunc && !p->fg.isIndexedBy );
      p->u1.nRow++;
    }
  
    if( pParse->nErr==0 ){
      Subquery *pSubq;
      assert( p!=0 );
      assert( p->fg.isSubquery );
      pSubq = p->u4.pSubq;
      assert( pSubq!=0 );
      assert( pSubq->pSelect!=0 );
      assert( pSubq->pSelect->pEList!=0 );
      if( pSubq->pSelect->pEList->nExpr!=pRow->nExpr ){
        sqlite3SelectWrongNumTermsError(pParse, pSubq->pSelect);
      }else{
        sqlite3ExprCodeExprList(pParse, pRow, pSubq->regResult, 0, 0);
        sqlite3VdbeAddOp1(pParse->pVdbe, OP_Yield, pSubq->regReturn);
      }
    }
    sqlite3ExprListDelete(pParse->db, pRow);
  }

  return pLeft;
}

/* Forward declaration */
static int xferOptimization(
  Parse *pParse,        /* Parser context */
  Table *pDest,         /* The table we are inserting into */
  Select *pSelect,      /* A SELECT statement to use as the data source */
  int onError,          /* How to handle constraint errors */
  int iDbDest           /* The database of pDest */
);

/*
** This routine is called to handle SQL of the following forms:
**
**    insert into TABLE (IDLIST) values(EXPRLIST),(EXPRLIST),...
**    insert into TABLE (IDLIST) select
**    insert into TABLE (IDLIST) default values
**
** The IDLIST following the table name is always optional.  If omitted,
** then a list of all (non-hidden) columns for the table is substituted.
** The IDLIST appears in the pColumn parameter.  pColumn is NULL if IDLIST
** is omitted.
**
** For the pSelect parameter holds the values to be inserted for the
** first two forms shown above.  A VALUES clause is really just short-hand
** for a SELECT statement that omits the FROM clause and everything else
** that follows.  If the pSelect parameter is NULL, that means that the
** DEFAULT VALUES form of the INSERT statement is intended.
**
** The code generated follows one of four templates.  For a simple
** insert with data coming from a single-row VALUES clause, the code executes
** once straight down through.  Pseudo-code follows (we call this
** the "1st template"):
**
**         open write cursor to <table> and its indices
**         put VALUES clause expressions into registers
**         write the resulting record into <table>
**         cleanup
**
** The three remaining templates assume the statement is of the form
**
**   INSERT INTO <table> SELECT ...
**
** If the SELECT clause is of the restricted form "SELECT * FROM <table2>" -
** in other words if the SELECT pulls all columns from a single table
** and there is no WHERE or LIMIT or GROUP BY or ORDER BY clauses, and
** if <table2> and <table1> are distinct tables but have identical
** schemas, including all the same indices, then a special optimization
** is invoked that copies raw records from <table2> over to <table1>.
** See the xferOptimization() function for the implementation of this
** template.  This is the 2nd template.
**
**         open a write cursor to <table>
**         open read cursor on <table2>
**         transfer all records in <table2> over to <table>
**         close cursors
**         foreach index on <table>
**           open a write cursor on the <table> index
**           open a read cursor on the corresponding <table2> index
**           transfer all records from the read to the write cursors
**           close cursors
**         end foreach
**
** The 3rd template is for when the second template does not apply
** and the SELECT clause does not read from <table> at any time.
** The generated code follows this template:
**
**         X <- A
**         goto B
**      A: setup for the SELECT
**         loop over the rows in the SELECT
**           load values into registers R..R+n
**           yield X
**         end loop
**         cleanup after the SELECT
**         end-coroutine X
**      B: open write cursor to <table> and its indices
**      C: yield X, at EOF goto D
**         insert the select result into <table> from R..R+n
**         goto C
**      D: cleanup
**
** The 4th template is used if the insert statement takes its
** values from a SELECT but the data is being inserted into a table
** that is also read as part of the SELECT.  In the third form,
** we have to use an intermediate table to store the results of
** the select.  The template is like this:
**
**         X <- A
**         goto B
**      A: setup for the SELECT
**         loop over the tables in the SELECT
**           load value into register R..R+n
**           yield X
**         end loop
**         cleanup after the SELECT
**         end co-routine R
**      B: open temp table
**      L: yield X, at EOF goto M
**         insert row from R..R+n into temp table
**         goto L
**      M: open write cursor to <table> and its indices
**         rewind temp table
**      C: loop over rows of intermediate table
**           transfer values form intermediate table into <table>
**         end loop
**      D: cleanup
*/
void sqlite3Insert(
  Parse *pParse,        /* Parser context */
  SrcList *pTabList,    /* Name of table into which we are inserting */
  Select *pSelect,      /* A SELECT statement to use as the data source */
  IdList *pColumn,      /* Column names corresponding to IDLIST, or NULL. */
  int onError,          /* How to handle constraint errors */
  Upsert *pUpsert       /* ON CONFLICT clauses for upsert, or NULL */
){
  sqlite3 *db;          /* The main database structure */
  Table *pTab;          /* The table to insert into.  aka TABLE */
  int i, j;             /* Loop counters */
  Vdbe *v;              /* Generate code into this virtual machine */
  Index *pIdx;          /* For looping over indices of the table */
  int nColumn;          /* Number of columns in the data */
  int nHidden = 0;      /* Number of hidden columns if TABLE is virtual */
  int iDataCur = 0;     /* VDBE cursor that is the main data repository */
  int iIdxCur = 0;      /* First index cursor */
  int ipkColumn = -1;   /* Column that is the INTEGER PRIMARY KEY */
  int endOfLoop;        /* Label for the end of the insertion loop */
  int srcTab = 0;       /* Data comes from this temporary cursor if >=0 */
  int addrInsTop = 0;   /* Jump to label "D" */
  int addrCont = 0;     /* Top of insert loop. Label "C" in templates 3 and 4 */
  SelectDest dest;      /* Destination for SELECT on rhs of INSERT */
  int iDb;              /* Index of database holding TABLE */
  u8 useTempTable = 0;  /* Store SELECT results in intermediate table */
  u8 appendFlag = 0;    /* True if the insert is likely to be an append */
  u8 withoutRowid;      /* 0 for normal table.  1 for WITHOUT ROWID table */
  u8 bIdListInOrder;    /* True if IDLIST is in table order */
  ExprList *pList = 0;  /* List of VALUES() to be inserted  */
  int iRegStore;        /* Register in which to store next column */

  /* Register allocations */
  int regFromSelect = 0;/* Base register for data coming from SELECT */
  int regAutoinc = 0;   /* Register holding the AUTOINCREMENT counter */
  int regRowCount = 0;  /* Memory cell used for the row counter */
  int regIns;           /* Block of regs holding rowid+data being inserted */
  int regRowid;         /* registers holding insert rowid */
  int regData;          /* register holding first column to insert */
  int *aRegIdx = 0;     /* One register allocated to each index */
  int *aTabColMap = 0;  /* Mapping from pTab columns to pCol entries */

#ifndef SQLITE_OMIT_TRIGGER
  int isView;                 /* True if attempting to insert into a view */
  Trigger *pTrigger;          /* List of triggers on pTab, if required */
  int tmask;                  /* Mask of trigger times */
#endif

  db = pParse->db;
  assert( db->pParse==pParse );
  if( pParse->nErr ){
    goto insert_cleanup;
  }
  assert( db->mallocFailed==0 );
  dest.iSDParm = 0;  /* Suppress a harmless compiler warning */

  /* If the Select object is really just a simple VALUES() list with a
  ** single row (the common case) then keep that one row of values
  ** and discard the other (unused) parts of the pSelect object
  */
  if( pSelect && (pSelect->selFlags & SF_Values)!=0 && pSelect->pPrior==0 ){
    pList = pSelect->pEList;
    pSelect->pEList = 0;
    sqlite3SelectDelete(db, pSelect);
    pSelect = 0;
  }

  /* Locate the table into which we will be inserting new information.
  */
  assert( pTabList->nSrc==1 );
  pTab = sqlite3SrcListLookup(pParse, pTabList);
  if( pTab==0 ){
    goto insert_cleanup;
  }
  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
  assert( iDb<db->nDb );
  if( sqlite3AuthCheck(pParse, SQLITE_INSERT, pTab->zName, 0,
                       db->aDb[iDb].zDbSName) ){
    goto insert_cleanup;
  }
  withoutRowid = !HasRowid(pTab);

  /* Figure out if we have any triggers and if the table being
  ** inserted into is a view
  */
#ifndef SQLITE_OMIT_TRIGGER
  pTrigger = sqlite3TriggersExist(pParse, pTab, TK_INSERT, 0, &tmask);
  isView = IsView(pTab);
#else
# define pTrigger 0
# define tmask 0
# define isView 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif
  assert( (pTrigger && tmask) || (pTrigger==0 && tmask==0) );

#if TREETRACE_ENABLED
  if( sqlite3TreeTrace & 0x10000 ){
    sqlite3TreeViewLine(0, "In sqlite3Insert() at %s:%d", __FILE__, __LINE__);
    sqlite3TreeViewInsert(pParse->pWith, pTabList, pColumn, pSelect, pList,
                          onError, pUpsert, pTrigger);
  }
#endif

  /* If pTab is really a view, make sure it has been initialized.
  ** ViewGetColumnNames() is a no-op if pTab is not a view.
  */
  if( sqlite3ViewGetColumnNames(pParse, pTab) ){
    goto insert_cleanup;
  }

  /* Cannot insert into a read-only table.
  */
  if( sqlite3IsReadOnly(pParse, pTab, pTrigger) ){
    goto insert_cleanup;
  }

  /* Allocate a VDBE
  */
  v = sqlite3GetVdbe(pParse);
  if( v==0 ) goto insert_cleanup;
  if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
  sqlite3BeginWriteOperation(pParse, pSelect || pTrigger, iDb);

#ifndef SQLITE_OMIT_XFER_OPT
  /* If the statement is of the form
  **
  **       INSERT INTO <table1> SELECT * FROM <table2>;
  **
  ** Then special optimizations can be applied that make the transfer
  ** very fast and which reduce fragmentation of indices.
  **
  ** This is the 2nd template.
  */
  if( pColumn==0
   && pSelect!=0
   && pTrigger==0
   && xferOptimization(pParse, pTab, pSelect, onError, iDb)
  ){
    assert( !pTrigger );
    assert( pList==0 );
    goto insert_end;
  }
#endif /* SQLITE_OMIT_XFER_OPT */

  /* If this is an AUTOINCREMENT table, look up the sequence number in the
  ** sqlite_sequence table and store it in memory cell regAutoinc.
  */
  regAutoinc = autoIncBegin(pParse, iDb, pTab);

  /* Allocate a block registers to hold the rowid and the values
  ** for all columns of the new row.
  */
  regRowid = regIns = pParse->nMem+1;
  pParse->nMem += pTab->nCol + 1;
  if( IsVirtual(pTab) ){
    regRowid++;
    pParse->nMem++;
  }
  regData = regRowid+1;

  /* If the INSERT statement included an IDLIST term, then make sure
  ** all elements of the IDLIST really are columns of the table and
  ** remember the column indices.
  **
  ** If the table has an INTEGER PRIMARY KEY column and that column
  ** is named in the IDLIST, then record in the ipkColumn variable
  ** the index into IDLIST of the primary key column.  ipkColumn is
  ** the index of the primary key as it appears in IDLIST, not as
  ** is appears in the original table.  (The index of the INTEGER
  ** PRIMARY KEY in the original table is pTab->iPKey.)  After this
  ** loop, if ipkColumn==(-1), that means that integer primary key
  ** is unspecified, and hence the table is either WITHOUT ROWID or
  ** it will automatically generated an integer primary key.
  **
  ** bIdListInOrder is true if the columns in IDLIST are in storage
  ** order.  This enables an optimization that avoids shuffling the
  ** columns into storage order.  False negatives are harmless,
  ** but false positives will cause database corruption.
  */
  bIdListInOrder = (pTab->tabFlags & (TF_OOOHidden|TF_HasStored))==0;
  if( pColumn ){
    aTabColMap = sqlite3DbMallocZero(db, pTab->nCol*sizeof(int));
    if( aTabColMap==0 ) goto insert_cleanup;
    for(i=0; i<pColumn->nId; i++){
      j = sqlite3ColumnIndex(pTab, pColumn->a[i].zName);
      if( j>=0 ){
        if( aTabColMap[j]==0 ) aTabColMap[j] = i+1;
        if( i!=j ) bIdListInOrder = 0;
        if( j==pTab->iPKey ){
          ipkColumn = i;  assert( !withoutRowid );
        }
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
        if( pTab->aCol[j].colFlags & (COLFLAG_STORED|COLFLAG_VIRTUAL) ){
          sqlite3ErrorMsg(pParse,
             "cannot INSERT into generated column \"%s\"",
             pTab->aCol[j].zCnName);
          goto insert_cleanup;
        }
#endif
      }else{
        if( sqlite3IsRowid(pColumn->a[i].zName) && !withoutRowid ){
          ipkColumn = i;
          bIdListInOrder = 0;
        }else{
          sqlite3ErrorMsg(pParse, "table %S has no column named %s",
              pTabList->a, pColumn->a[i].zName);
          pParse->checkSchema = 1;
          goto insert_cleanup;
        }
      }
    }
  }

  /* Figure out how many columns of data are supplied.  If the data
  ** is coming from a SELECT statement, then generate a co-routine that
  ** produces a single row of the SELECT on each invocation.  The
  ** co-routine is the common header to the 3rd and 4th templates.
  */
  if( pSelect ){
    /* Data is coming from a SELECT or from a multi-row VALUES clause.
    ** Generate a co-routine to run the SELECT. */
    int rc;             /* Result code */

    if( pSelect->pSrc->nSrc==1 
     && pSelect->pSrc->a[0].fg.viaCoroutine 
     && pSelect->pPrior==0
    ){
      SrcItem *pItem = &pSelect->pSrc->a[0];
      Subquery *pSubq;
      assert( pItem->fg.isSubquery );
      pSubq = pItem->u4.pSubq;
      dest.iSDParm = pSubq->regReturn;
      regFromSelect = pSubq->regResult;
      assert( pSubq->pSelect!=0 );
      assert( pSubq->pSelect->pEList!=0 );
      nColumn = pSubq->pSelect->pEList->nExpr;
      ExplainQueryPlan((pParse, 0, "SCAN %S", pItem));
      if( bIdListInOrder && nColumn==pTab->nCol ){
        regData = regFromSelect;
        regRowid = regData - 1;
        regIns = regRowid - (IsVirtual(pTab) ? 1 : 0);
      }
    }else{
      int addrTop;        /* Top of the co-routine */
      int regYield = ++pParse->nMem;
      addrTop = sqlite3VdbeCurrentAddr(v) + 1;
      sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, addrTop);
      sqlite3SelectDestInit(&dest, SRT_Coroutine, regYield);
      dest.iSdst = bIdListInOrder ? regData : 0;
      dest.nSdst = pTab->nCol;
      rc = sqlite3Select(pParse, pSelect, &dest);
      regFromSelect = dest.iSdst;
      assert( db->pParse==pParse );
      if( rc || pParse->nErr ) goto insert_cleanup;
      assert( db->mallocFailed==0 );
      sqlite3VdbeEndCoroutine(v, regYield);
      sqlite3VdbeJumpHere(v, addrTop - 1);                       /* label B: */
      assert( pSelect->pEList );
      nColumn = pSelect->pEList->nExpr;
    }

    /* Set useTempTable to TRUE if the result of the SELECT statement
    ** should be written into a temporary table (template 4).  Set to
    ** FALSE if each output row of the SELECT can be written directly into
    ** the destination table (template 3).
    **
    ** A temp table must be used if the table being updated is also one
    ** of the tables being read by the SELECT statement.  Also use a
    ** temp table in the case of row triggers.
    */
    if( pTrigger || readsTable(pParse, iDb, pTab) ){
      useTempTable = 1;
    }

    if( useTempTable ){
      /* Invoke the coroutine to extract information from the SELECT
      ** and add it to a transient table srcTab.  The code generated
      ** here is from the 4th template:
      **
      **      B: open temp table
      **      L: yield X, goto M at EOF
      **         insert row from R..R+n into temp table
      **         goto L
      **      M: ...
      */
      int regRec;          /* Register to hold packed record */
      int regTempRowid;    /* Register to hold temp table ROWID */
      int addrL;           /* Label "L" */

      srcTab = pParse->nTab++;
      regRec = sqlite3GetTempReg(pParse);
      regTempRowid = sqlite3GetTempReg(pParse);
      sqlite3VdbeAddOp2(v, OP_OpenEphemeral, srcTab, nColumn);
      addrL = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm); VdbeCoverage(v);
      sqlite3VdbeAddOp3(v, OP_MakeRecord, regFromSelect, nColumn, regRec);
      sqlite3VdbeAddOp2(v, OP_NewRowid, srcTab, regTempRowid);
      sqlite3VdbeAddOp3(v, OP_Insert, srcTab, regRec, regTempRowid);
      sqlite3VdbeGoto(v, addrL);
      sqlite3VdbeJumpHere(v, addrL);
      sqlite3ReleaseTempReg(pParse, regRec);
      sqlite3ReleaseTempReg(pParse, regTempRowid);
    }
  }else{
    /* This is the case if the data for the INSERT is coming from a
    ** single-row VALUES clause
    */
    NameContext sNC;
    memset(&sNC, 0, sizeof(sNC));
    sNC.pParse = pParse;
    srcTab = -1;
    assert( useTempTable==0 );
    if( pList ){
      nColumn = pList->nExpr;
      if( sqlite3ResolveExprListNames(&sNC, pList) ){
        goto insert_cleanup;
      }
    }else{
      nColumn = 0;
    }
  }

  /* If there is no IDLIST term but the table has an integer primary
  ** key, the set the ipkColumn variable to the integer primary key
  ** column index in the original table definition.
  */
  if( pColumn==0 && nColumn>0 ){
    ipkColumn = pTab->iPKey;
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
    if( ipkColumn>=0 && (pTab->tabFlags & TF_HasGenerated)!=0 ){
      testcase( pTab->tabFlags & TF_HasVirtual );
      testcase( pTab->tabFlags & TF_HasStored );
      for(i=ipkColumn-1; i>=0; i--){
        if( pTab->aCol[i].colFlags & COLFLAG_GENERATED ){
          testcase( pTab->aCol[i].colFlags & COLFLAG_VIRTUAL );
          testcase( pTab->aCol[i].colFlags & COLFLAG_STORED );
          ipkColumn--;
        }
      }
    }
#endif

    /* Make sure the number of columns in the source data matches the number
    ** of columns to be inserted into the table.
    */
    assert( TF_HasHidden==COLFLAG_HIDDEN );
    assert( TF_HasGenerated==COLFLAG_GENERATED );
    assert( COLFLAG_NOINSERT==(COLFLAG_GENERATED|COLFLAG_HIDDEN) );
    if( (pTab->tabFlags & (TF_HasGenerated|TF_HasHidden))!=0 ){
      for(i=0; i<pTab->nCol; i++){
        if( pTab->aCol[i].colFlags & COLFLAG_NOINSERT ) nHidden++;
      }
    }
    if( nColumn!=(pTab->nCol-nHidden) ){
      sqlite3ErrorMsg(pParse,
         "table %S has %d columns but %d values were supplied",
         pTabList->a, pTab->nCol-nHidden, nColumn);
     goto insert_cleanup;
    }
  }
  if( pColumn!=0 && nColumn!=pColumn->nId ){
    sqlite3ErrorMsg(pParse, "%d values for %d columns", nColumn, pColumn->nId);
    goto insert_cleanup;
  }
   
  /* Initialize the count of rows to be inserted
  */
  if( (db->flags & SQLITE_CountRows)!=0
   && !pParse->nested
   && !pParse->pTriggerTab
   && !pParse->bReturning
  ){
    regRowCount = ++pParse->nMem;
    sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);
  }

  /* If this is not a view, open the table and and all indices */
  if( !isView ){
    int nIdx;
    nIdx = sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, 0, -1, 0,
                                      &iDataCur, &iIdxCur);
    aRegIdx = sqlite3DbMallocRawNN(db, sizeof(int)*(nIdx+2));
    if( aRegIdx==0 ){
      goto insert_cleanup;
    }
    for(i=0, pIdx=pTab->pIndex; i<nIdx; pIdx=pIdx->pNext, i++){
      assert( pIdx );
      aRegIdx[i] = ++pParse->nMem;
      pParse->nMem += pIdx->nColumn;
    }
    aRegIdx[i] = ++pParse->nMem;  /* Register to store the table record */
  }
#ifndef SQLITE_OMIT_UPSERT
  if( pUpsert ){
    Upsert *pNx;
    if( IsVirtual(pTab) ){
      sqlite3ErrorMsg(pParse, "UPSERT not implemented for virtual table \"%s\"",
              pTab->zName);
      goto insert_cleanup;
    }
    if( IsView(pTab) ){
      sqlite3ErrorMsg(pParse, "cannot UPSERT a view");
      goto insert_cleanup;
    }
    if( sqlite3HasExplicitNulls(pParse, pUpsert->pUpsertTarget) ){
      goto insert_cleanup;
    }
    pTabList->a[0].iCursor = iDataCur;
    pNx = pUpsert;
    do{
      pNx->pUpsertSrc = pTabList;
      pNx->regData = regData;
      pNx->iDataCur = iDataCur;
      pNx->iIdxCur = iIdxCur;
      if( pNx->pUpsertTarget ){
        if( sqlite3UpsertAnalyzeTarget(pParse, pTabList, pNx, pUpsert) ){
          goto insert_cleanup;
        }
      }
      pNx = pNx->pNextUpsert;
    }while( pNx!=0 );
  }
#endif


  /* This is the top of the main insertion loop */
  if( useTempTable ){
    /* This block codes the top of loop only.  The complete loop is the
    ** following pseudocode (template 4):
    **
    **         rewind temp table, if empty goto D
    **      C: loop over rows of intermediate table
    **           transfer values form intermediate table into <table>
    **         end loop
    **      D: ...
    */
    addrInsTop = sqlite3VdbeAddOp1(v, OP_Rewind, srcTab); VdbeCoverage(v);
    addrCont = sqlite3VdbeCurrentAddr(v);
  }else if( pSelect ){
    /* This block codes the top of loop only.  The complete loop is the
    ** following pseudocode (template 3):
    **
    **      C: yield X, at EOF goto D
    **         insert the select result into <table> from R..R+n
    **         goto C
    **      D: ...
    */
    sqlite3VdbeReleaseRegisters(pParse, regData, pTab->nCol, 0, 0);
    addrInsTop = addrCont = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm);
    VdbeCoverage(v);
    if( ipkColumn>=0 ){
      /* tag-20191021-001: If the INTEGER PRIMARY KEY is being generated by the
      ** SELECT, go ahead and copy the value into the rowid slot now, so that
      ** the value does not get overwritten by a NULL at tag-20191021-002. */
      sqlite3VdbeAddOp2(v, OP_Copy, regFromSelect+ipkColumn, regRowid);
    }
  }

  /* Compute data for ordinary columns of the new entry.  Values
  ** are written in storage order into registers starting with regData.
  ** Only ordinary columns are computed in this loop. The rowid
  ** (if there is one) is computed later and generated columns are
  ** computed after the rowid since they might depend on the value
  ** of the rowid.
  */
  nHidden = 0;
  iRegStore = regData;  assert( regData==regRowid+1 );
  for(i=0; i<pTab->nCol; i++, iRegStore++){
    int k;
    u32 colFlags;
    assert( i>=nHidden );
    if( i==pTab->iPKey ){
      /* tag-20191021-002: References to the INTEGER PRIMARY KEY are filled
      ** using the rowid. So put a NULL in the IPK slot of the record to avoid
      ** using excess space.  The file format definition requires this extra
      ** NULL - we cannot optimize further by skipping the column completely */
      sqlite3VdbeAddOp1(v, OP_SoftNull, iRegStore);
      continue;
    }
    if( ((colFlags = pTab->aCol[i].colFlags) & COLFLAG_NOINSERT)!=0 ){
      nHidden++;
      if( (colFlags & COLFLAG_VIRTUAL)!=0 ){
        /* Virtual columns do not participate in OP_MakeRecord.  So back up
        ** iRegStore by one slot to compensate for the iRegStore++ in the
        ** outer for() loop */
        iRegStore--;
        continue;
      }else if( (colFlags & COLFLAG_STORED)!=0 ){
        /* Stored columns are computed later.  But if there are BEFORE
        ** triggers, the slots used for stored columns will be OP_Copy-ed
        ** to a second block of registers, so the register needs to be
        ** initialized to NULL to avoid an uninitialized register read */
        if( tmask & TRIGGER_BEFORE ){
          sqlite3VdbeAddOp1(v, OP_SoftNull, iRegStore);
        }
        continue;
      }else if( pColumn==0 ){
        /* Hidden columns that are not explicitly named in the INSERT
        ** get their default value */
        sqlite3ExprCodeFactorable(pParse,
            sqlite3ColumnExpr(pTab, &pTab->aCol[i]),
            iRegStore);
        continue;
      }
    }
    if( pColumn ){
      j = aTabColMap[i];
      assert( j>=0 && j<=pColumn->nId );   
      if( j==0 ){
        /* A column not named in the insert column list gets its
        ** default value */
        sqlite3ExprCodeFactorable(pParse,
            sqlite3ColumnExpr(pTab, &pTab->aCol[i]),
            iRegStore);
        continue;
      }
      k = j - 1;
    }else if( nColumn==0 ){
      /* This is INSERT INTO ... DEFAULT VALUES.  Load the default value. */
      sqlite3ExprCodeFactorable(pParse,
          sqlite3ColumnExpr(pTab, &pTab->aCol[i]),
          iRegStore);
      continue;
    }else{
      k = i - nHidden;
    }

    if( useTempTable ){
      sqlite3VdbeAddOp3(v, OP_Column, srcTab, k, iRegStore);
    }else if( pSelect ){
      if( regFromSelect!=regData ){
        sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+k, iRegStore);
      }
    }else{
      Expr *pX = pList->a[k].pExpr;
      int y = sqlite3ExprCodeTarget(pParse, pX, iRegStore);
      if( y!=iRegStore ){
        sqlite3VdbeAddOp2(v,
          ExprHasProperty(pX, EP_Subquery) ? OP_Copy : OP_SCopy, y, iRegStore);
      }
    }
  }


  /* Run the BEFORE and INSTEAD OF triggers, if there are any
  */
  endOfLoop = sqlite3VdbeMakeLabel(pParse);
  if( tmask & TRIGGER_BEFORE ){
    int regCols = sqlite3GetTempRange(pParse, pTab->nCol+1);

    /* build the NEW.* reference row.  Note that if there is an INTEGER
    ** PRIMARY KEY into which a NULL is being inserted, that NULL will be
    ** translated into a unique ID for the row.  But on a BEFORE trigger,
    ** we do not know what the unique ID will be (because the insert has
    ** not happened yet) so we substitute a rowid of -1
    */
    if( ipkColumn<0 ){
      sqlite3VdbeAddOp2(v, OP_Integer, -1, regCols);
    }else{
      int addr1;
      assert( !withoutRowid );
      if( useTempTable ){
        sqlite3VdbeAddOp3(v, OP_Column, srcTab, ipkColumn, regCols);
      }else{
        assert( pSelect==0 );  /* Otherwise useTempTable is true */
        sqlite3ExprCode(pParse, pList->a[ipkColumn].pExpr, regCols);
      }
      addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, regCols); VdbeCoverage(v);
      sqlite3VdbeAddOp2(v, OP_Integer, -1, regCols);
      sqlite3VdbeJumpHere(v, addr1);
      sqlite3VdbeAddOp1(v, OP_MustBeInt, regCols); VdbeCoverage(v);
    }

    /* Copy the new data already generated. */
    assert( pTab->nNVCol>0 || pParse->nErr>0 );
    sqlite3VdbeAddOp3(v, OP_Copy, regRowid+1, regCols+1, pTab->nNVCol-1);

#ifndef SQLITE_OMIT_GENERATED_COLUMNS
    /* Compute the new value for generated columns after all other
    ** columns have already been computed.  This must be done after
    ** computing the ROWID in case one of the generated columns
    ** refers to the ROWID. */
    if( pTab->tabFlags & TF_HasGenerated ){
      testcase( pTab->tabFlags & TF_HasVirtual );
      testcase( pTab->tabFlags & TF_HasStored );
      sqlite3ComputeGeneratedColumns(pParse, regCols+1, pTab);
    }
#endif

    /* If this is an INSERT on a view with an INSTEAD OF INSERT trigger,
    ** do not attempt any conversions before assembling the record.
    ** If this is a real table, attempt conversions as required by the
    ** table column affinities.
    */
    if( !isView ){
      sqlite3TableAffinity(v, pTab, regCols+1);
    }

    /* Fire BEFORE or INSTEAD OF triggers */
    sqlite3CodeRowTrigger(pParse, pTrigger, TK_INSERT, 0, TRIGGER_BEFORE,
        pTab, regCols-pTab->nCol-1, onError, endOfLoop);

    sqlite3ReleaseTempRange(pParse, regCols, pTab->nCol+1);
  }

  if( !isView ){
    if( IsVirtual(pTab) ){
      /* The row that the VUpdate opcode will delete: none */
      sqlite3VdbeAddOp2(v, OP_Null, 0, regIns);
    }
    if( ipkColumn>=0 ){
      /* Compute the new rowid */
      if( useTempTable ){
        sqlite3VdbeAddOp3(v, OP_Column, srcTab, ipkColumn, regRowid);
      }else if( pSelect ){
        /* Rowid already initialized at tag-20191021-001 */
      }else{
        Expr *pIpk = pList->a[ipkColumn].pExpr;
        if( pIpk->op==TK_NULL && !IsVirtual(pTab) ){
          sqlite3VdbeAddOp3(v, OP_NewRowid, iDataCur, regRowid, regAutoinc);
          appendFlag = 1;
        }else{
          sqlite3ExprCode(pParse, pList->a[ipkColumn].pExpr, regRowid);
        }
      }
      /* If the PRIMARY KEY expression is NULL, then use OP_NewRowid
      ** to generate a unique primary key value.
      */
      if( !appendFlag ){
        int addr1;
        if( !IsVirtual(pTab) ){
          addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, regRowid); VdbeCoverage(v);
          sqlite3VdbeAddOp3(v, OP_NewRowid, iDataCur, regRowid, regAutoinc);
          sqlite3VdbeJumpHere(v, addr1);
        }else{
          addr1 = sqlite3VdbeCurrentAddr(v);
          sqlite3VdbeAddOp2(v, OP_IsNull, regRowid, addr1+2); VdbeCoverage(v);
        }
        sqlite3VdbeAddOp1(v, OP_MustBeInt, regRowid); VdbeCoverage(v);
      }
    }else if( IsVirtual(pTab) || withoutRowid ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, regRowid);
    }else{
      sqlite3VdbeAddOp3(v, OP_NewRowid, iDataCur, regRowid, regAutoinc);
      appendFlag = 1;
    }
    autoIncStep(pParse, regAutoinc, regRowid);

#ifndef SQLITE_OMIT_GENERATED_COLUMNS
    /* Compute the new value for generated columns after all other
    ** columns have already been computed.  This must be done after
    ** computing the ROWID in case one of the generated columns
    ** is derived from the INTEGER PRIMARY KEY. */
    if( pTab->tabFlags & TF_HasGenerated ){
      sqlite3ComputeGeneratedColumns(pParse, regRowid+1, pTab);
    }
#endif

    /* Generate code to check constraints and generate index keys and
    ** do the insertion.
    */
#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( IsVirtual(pTab) ){
      const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
      sqlite3VtabMakeWritable(pParse, pTab);
      sqlite3VdbeAddOp4(v, OP_VUpdate, 1, pTab->nCol+2, regIns, pVTab, P4_VTAB);
      sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError);
      sqlite3MayAbort(pParse);
    }else
#endif
    {
      int isReplace = 0;/* Set to true if constraints may cause a replace */
      int bUseSeek;     /* True to use OPFLAG_SEEKRESULT */
      sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,
          regIns, 0, ipkColumn>=0, onError, endOfLoop, &isReplace, 0, pUpsert
      );
      if( db->flags & SQLITE_ForeignKeys ){
        sqlite3FkCheck(pParse, pTab, 0, regIns, 0, 0);
      }

      /* Set the OPFLAG_USESEEKRESULT flag if either (a) there are no REPLACE
      ** constraints or (b) there are no triggers and this table is not a
      ** parent table in a foreign key constraint. It is safe to set the
      ** flag in the second case as if any REPLACE constraint is hit, an
      ** OP_Delete or OP_IdxDelete instruction will be executed on each
      ** cursor that is disturbed. And these instructions both clear the
      ** VdbeCursor.seekResult variable, disabling the OPFLAG_USESEEKRESULT
      ** functionality.  */
      bUseSeek = (isReplace==0 || !sqlite3VdbeHasSubProgram(v));
      sqlite3CompleteInsertion(pParse, pTab, iDataCur, iIdxCur,
          regIns, aRegIdx, 0, appendFlag, bUseSeek
      );
    }
#ifdef SQLITE_ALLOW_ROWID_IN_VIEW
  }else if( pParse->bReturning ){
    /* If there is a RETURNING clause, populate the rowid register with
    ** constant value -1, in case one or more of the returned expressions
    ** refer to the "rowid" of the view.  */
    sqlite3VdbeAddOp2(v, OP_Integer, -1, regRowid);
#endif
  }

  /* Update the count of rows that are inserted
  */
  if( regRowCount ){
    sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);
  }

  if( pTrigger ){
    /* Code AFTER triggers */
    sqlite3CodeRowTrigger(pParse, pTrigger, TK_INSERT, 0, TRIGGER_AFTER,
        pTab, regData-2-pTab->nCol, onError, endOfLoop);
  }

  /* The bottom of the main insertion loop, if the data source
  ** is a SELECT statement.
  */
  sqlite3VdbeResolveLabel(v, endOfLoop);
  if( useTempTable ){
    sqlite3VdbeAddOp2(v, OP_Next, srcTab, addrCont); VdbeCoverage(v);
    sqlite3VdbeJumpHere(v, addrInsTop);
    sqlite3VdbeAddOp1(v, OP_Close, srcTab);
  }else if( pSelect ){
    sqlite3VdbeGoto(v, addrCont);
#ifdef SQLITE_DEBUG
    /* If we are jumping back to an OP_Yield that is preceded by an
    ** OP_ReleaseReg, set the p5 flag on the OP_Goto so that the
    ** OP_ReleaseReg will be included in the loop. */
    if( sqlite3VdbeGetOp(v, addrCont-1)->opcode==OP_ReleaseReg ){
      assert( sqlite3VdbeGetOp(v, addrCont)->opcode==OP_Yield );
      sqlite3VdbeChangeP5(v, 1);
    }
#endif
    sqlite3VdbeJumpHere(v, addrInsTop);
  }

#ifndef SQLITE_OMIT_XFER_OPT
insert_end:
#endif /* SQLITE_OMIT_XFER_OPT */
  /* Update the sqlite_sequence table by storing the content of the
  ** maximum rowid counter values recorded while inserting into
  ** autoincrement tables.
  */
  if( pParse->nested==0 && pParse->pTriggerTab==0 ){
    sqlite3AutoincrementEnd(pParse);
  }

  /*
  ** Return the number of rows inserted. If this routine is
  ** generating code because of a call to sqlite3NestedParse(), do not
  ** invoke the callback function.
  */
  if( regRowCount ){
    sqlite3CodeChangeCount(v, regRowCount, "rows inserted");
  }

insert_cleanup:
  sqlite3SrcListDelete(db, pTabList);
  sqlite3ExprListDelete(db, pList);
  sqlite3UpsertDelete(db, pUpsert);
  sqlite3SelectDelete(db, pSelect);
  if( pColumn ){
    sqlite3IdListDelete(db, pColumn);
    sqlite3DbFree(db, aTabColMap);
  }
  if( aRegIdx ) sqlite3DbNNFreeNN(db, aRegIdx);
}

/* Make sure "isView" and other macros defined above are undefined. Otherwise
** they may interfere with compilation of other functions in this file
** (or in another file, if this file becomes part of the amalgamation).  */
#ifdef isView
 #undef isView
#endif
#ifdef pTrigger
 #undef pTrigger
#endif
#ifdef tmask
 #undef tmask
#endif

/*
** Meanings of bits in of pWalker->eCode for
** sqlite3ExprReferencesUpdatedColumn()
*/
#define CKCNSTRNT_COLUMN   0x01    /* CHECK constraint uses a changing column */
#define CKCNSTRNT_ROWID    0x02    /* CHECK constraint references the ROWID */

/* This is the Walker callback from sqlite3ExprReferencesUpdatedColumn().
*  Set bit 0x01 of pWalker->eCode if pWalker->eCode to 0 and if this
** expression node references any of the
** columns that are being modified by an UPDATE statement.
*/
static int checkConstraintExprNode(Walker *pWalker, Expr *pExpr){
  if( pExpr->op==TK_COLUMN ){
    assert( pExpr->iColumn>=0 || pExpr->iColumn==-1 );
    if( pExpr->iColumn>=0 ){
      if( pWalker->u.aiCol[pExpr->iColumn]>=0 ){
        pWalker->eCode |= CKCNSTRNT_COLUMN;
      }
    }else{
      pWalker->eCode |= CKCNSTRNT_ROWID;
    }
  }
  return WRC_Continue;
}

/*
** pExpr is a CHECK constraint on a row that is being UPDATE-ed.  The
** only columns that are modified by the UPDATE are those for which
** aiChng[i]>=0, and also the ROWID is modified if chngRowid is true.
**
** Return true if CHECK constraint pExpr uses any of the
** changing columns (or the rowid if it is changing).  In other words,
** return true if this CHECK constraint must be validated for
** the new row in the UPDATE statement.
**
** 2018-09-15: pExpr might also be an expression for an index-on-expressions.
** The operation of this routine is the same - return true if an only if
** the expression uses one or more of columns identified by the second and
** third arguments.
*/
int sqlite3ExprReferencesUpdatedColumn(
  Expr *pExpr,    /* The expression to be checked */
  int *aiChng,    /* aiChng[x]>=0 if column x changed by the UPDATE */
  int chngRowid   /* True if UPDATE changes the rowid */
){
  Walker w;
  memset(&w, 0, sizeof(w));
  w.eCode = 0;
  w.xExprCallback = checkConstraintExprNode;
  w.u.aiCol = aiChng;
  sqlite3WalkExpr(&w, pExpr);
  if( !chngRowid ){
    testcase( (w.eCode & CKCNSTRNT_ROWID)!=0 );
    w.eCode &= ~CKCNSTRNT_ROWID;
  }
  testcase( w.eCode==0 );
  testcase( w.eCode==CKCNSTRNT_COLUMN );
  testcase( w.eCode==CKCNSTRNT_ROWID );
  testcase( w.eCode==(CKCNSTRNT_ROWID|CKCNSTRNT_COLUMN) );
  return w.eCode!=0;
}

/*
** The sqlite3GenerateConstraintChecks() routine usually wants to visit
** the indexes of a table in the order provided in the Table->pIndex list.
** However, sometimes (rarely - when there is an upsert) it wants to visit
** the indexes in a different order.  The following data structures accomplish
** this.
**
** The IndexIterator object is used to walk through all of the indexes
** of a table in either Index.pNext order, or in some other order established
** by an array of IndexListTerm objects.
*/
typedef struct IndexListTerm IndexListTerm;
typedef struct IndexIterator IndexIterator;
struct IndexIterator {
  int eType;    /* 0 for Index.pNext list.  1 for an array of IndexListTerm */
  int i;        /* Index of the current item from the list */
  union {
    struct {    /* Use this object for eType==0: A Index.pNext list */
      Index *pIdx;   /* The current Index */
    } lx;     
    struct {    /* Use this object for eType==1; Array of IndexListTerm */
      int nIdx;               /* Size of the array */
      IndexListTerm *aIdx;    /* Array of IndexListTerms */
    } ax;
  } u;
};

/* When IndexIterator.eType==1, then each index is an array of instances
** of the following object
*/
struct IndexListTerm {
  Index *p;  /* The index */
  int ix;    /* Which entry in the original Table.pIndex list is this index*/
};

/* Return the first index on the list */
static Index *indexIteratorFirst(IndexIterator *pIter, int *pIx){
  assert( pIter->i==0 );
  if( pIter->eType ){
    *pIx = pIter->u.ax.aIdx[0].ix;
    return pIter->u.ax.aIdx[0].p;
  }else{
    *pIx = 0;
    return pIter->u.lx.pIdx;
  }
}

/* Return the next index from the list.  Return NULL when out of indexes */
static Index *indexIteratorNext(IndexIterator *pIter, int *pIx){
  if( pIter->eType ){
    int i = ++pIter->i;
    if( i>=pIter->u.ax.nIdx ){
      *pIx = i;
      return 0;
    }
    *pIx = pIter->u.ax.aIdx[i].ix;
    return pIter->u.ax.aIdx[i].p;
  }else{
    ++(*pIx);
    pIter->u.lx.pIdx = pIter->u.lx.pIdx->pNext;
    return pIter->u.lx.pIdx;
  }
}
 
/*
** Generate code to do constraint checks prior to an INSERT or an UPDATE
** on table pTab.
**
** The regNewData parameter is the first register in a range that contains
** the data to be inserted or the data after the update.  There will be
** pTab->nCol+1 registers in this range.  The first register (the one
** that regNewData points to) will contain the new rowid, or NULL in the
** case of a WITHOUT ROWID table.  The second register in the range will
** contain the content of the first table column.  The third register will
** contain the content of the second table column.  And so forth.
**
** The regOldData parameter is similar to regNewData except that it contains
** the data prior to an UPDATE rather than afterwards.  regOldData is zero
** for an INSERT.  This routine can distinguish between UPDATE and INSERT by
** checking regOldData for zero.
**
** For an UPDATE, the pkChng boolean is true if the true primary key (the
** rowid for a normal table or the PRIMARY KEY for a WITHOUT ROWID table)
** might be modified by the UPDATE.  If pkChng is false, then the key of
** the iDataCur content table is guaranteed to be unchanged by the UPDATE.
**
** For an INSERT, the pkChng boolean indicates whether or not the rowid
** was explicitly specified as part of the INSERT statement.  If pkChng
** is zero, it means that the either rowid is computed automatically or
** that the table is a WITHOUT ROWID table and has no rowid.  On an INSERT,
** pkChng will only be true if the INSERT statement provides an integer
** value for either the rowid column or its INTEGER PRIMARY KEY alias.
**
** The code generated by this routine will store new index entries into
** registers identified by aRegIdx[].  No index entry is created for
** indices where aRegIdx[i]==0.  The order of indices in aRegIdx[] is
** the same as the order of indices on the linked list of indices
** at pTab->pIndex.
**
** (2019-05-07) The generated code also creates a new record for the
** main table, if pTab is a rowid table, and stores that record in the
** register identified by aRegIdx[nIdx] - in other words in the first
** entry of aRegIdx[] past the last index.  It is important that the
** record be generated during constraint checks to avoid affinity changes
** to the register content that occur after constraint checks but before
** the new record is inserted.
**
** The caller must have already opened writeable cursors on the main
** table and all applicable indices (that is to say, all indices for which
** aRegIdx[] is not zero).  iDataCur is the cursor for the main table when
** inserting or updating a rowid table, or the cursor for the PRIMARY KEY
** index when operating on a WITHOUT ROWID table.  iIdxCur is the cursor
** for the first index in the pTab->pIndex list.  Cursors for other indices
** are at iIdxCur+N for the N-th element of the pTab->pIndex list.
**
** This routine also generates code to check constraints.  NOT NULL,
** CHECK, and UNIQUE constraints are all checked.  If a constraint fails,
** then the appropriate action is performed.  There are five possible
** actions: ROLLBACK, ABORT, FAIL, REPLACE, and IGNORE.
**
**  Constraint type  Action       What Happens
**  ---------------  ----------   ----------------------------------------
**  any              ROLLBACK     The current transaction is rolled back and
**                                sqlite3_step() returns immediately with a
**                                return code of SQLITE_CONSTRAINT.
**
**  any              ABORT        Back out changes from the current command
**                                only (do not do a complete rollback) then
**                                cause sqlite3_step() to return immediately
**                                with SQLITE_CONSTRAINT.
**
**  any              FAIL         Sqlite3_step() returns immediately with a
**                                return code of SQLITE_CONSTRAINT.  The
**                                transaction is not rolled back and any
**                                changes to prior rows are retained.
**
**  any              IGNORE       The attempt in insert or update the current
**                                row is skipped, without throwing an error.
**                                Processing continues with the next row.
**                                (There is an immediate jump to ignoreDest.)
**
**  NOT NULL         REPLACE      The NULL value is replace by the default
**                                value for that column.  If the default value
**                                is NULL, the action is the same as ABORT.
**
**  UNIQUE           REPLACE      The other row that conflicts with the row
**                                being inserted is removed.
**
**  CHECK            REPLACE      Illegal.  The results in an exception.
**
** Which action to take is determined by the overrideError parameter.
** Or if overrideError==OE_Default, then the pParse->onError parameter
** is used.  Or if pParse->onError==OE_Default then the onError value
** for the constraint is used.
*/
void sqlite3GenerateConstraintChecks(
  Parse *pParse,       /* The parser context */
  Table *pTab,         /* The table being inserted or updated */
  int *aRegIdx,        /* Use register aRegIdx[i] for index i.  0 for unused */
  int iDataCur,        /* Canonical data cursor (main table or PK index) */
  int iIdxCur,         /* First index cursor */
  int regNewData,      /* First register in a range holding values to insert */
  int regOldData,      /* Previous content.  0 for INSERTs */
  u8 pkChng,           /* Non-zero if the rowid or PRIMARY KEY changed */
  u8 overrideError,    /* Override onError to this if not OE_Default */
  int ignoreDest,      /* Jump to this label on an OE_Ignore resolution */
  int *pbMayReplace,   /* OUT: Set to true if constraint may cause a replace */
  int *aiChng,         /* column i is unchanged if aiChng[i]<0 */
  Upsert *pUpsert      /* ON CONFLICT clauses, if any.  NULL otherwise */
){
  Vdbe *v;             /* VDBE under construction */
  Index *pIdx;         /* Pointer to one of the indices */
  Index *pPk = 0;      /* The PRIMARY KEY index for WITHOUT ROWID tables */
  sqlite3 *db;         /* Database connection */
  int i;               /* loop counter */
  int ix;              /* Index loop counter */
  int nCol;            /* Number of columns */
  int onError;         /* Conflict resolution strategy */
  int seenReplace = 0; /* True if REPLACE is used to resolve INT PK conflict */
  int nPkField;        /* Number of fields in PRIMARY KEY. 1 for ROWID tables */
  Upsert *pUpsertClause = 0;  /* The specific ON CONFLICT clause for pIdx */
  u8 isUpdate;           /* True if this is an UPDATE operation */
  u8 bAffinityDone = 0;  /* True if the OP_Affinity operation has been run */
  int upsertIpkReturn = 0; /* Address of Goto at end of IPK uniqueness check */
  int upsertIpkDelay = 0;  /* Address of Goto to bypass initial IPK check */
  int ipkTop = 0;        /* Top of the IPK uniqueness check */
  int ipkBottom = 0;     /* OP_Goto at the end of the IPK uniqueness check */
  /* Variables associated with retesting uniqueness constraints after
  ** replace triggers fire have run */
  int regTrigCnt;       /* Register used to count replace trigger invocations */
  int addrRecheck = 0;  /* Jump here to recheck all uniqueness constraints */
  int lblRecheckOk = 0; /* Each recheck jumps to this label if it passes */
  Trigger *pTrigger;    /* List of DELETE triggers on the table pTab */
  int nReplaceTrig = 0; /* Number of replace triggers coded */
  IndexIterator sIdxIter;  /* Index iterator */

  isUpdate = regOldData!=0;
  db = pParse->db;
  v = pParse->pVdbe;
  assert( v!=0 );
  assert( !IsView(pTab) );  /* This table is not a VIEW */
  nCol = pTab->nCol;
 
  /* pPk is the PRIMARY KEY index for WITHOUT ROWID tables and NULL for
  ** normal rowid tables.  nPkField is the number of key fields in the
  ** pPk index or 1 for a rowid table.  In other words, nPkField is the
  ** number of fields in the true primary key of the table. */
  if( HasRowid(pTab) ){
    pPk = 0;
    nPkField = 1;
  }else{
    pPk = sqlite3PrimaryKeyIndex(pTab);
    nPkField = pPk->nKeyCol;
  }

  /* Record that this module has started */
  VdbeModuleComment((v, "BEGIN: GenCnstCks(%d,%d,%d,%d,%d)",
                     iDataCur, iIdxCur, regNewData, regOldData, pkChng));

  /* Test all NOT NULL constraints.
  */
  if( pTab->tabFlags & TF_HasNotNull ){
    int b2ndPass = 0;         /* True if currently running 2nd pass */
    int nSeenReplace = 0;     /* Number of ON CONFLICT REPLACE operations */
    int nGenerated = 0;       /* Number of generated columns with NOT NULL */
    while(1){  /* Make 2 passes over columns. Exit loop via "break" */
      for(i=0; i<nCol; i++){
        int iReg;                        /* Register holding column value */
        Column *pCol = &pTab->aCol[i];   /* The column to check for NOT NULL */
        int isGenerated;                 /* non-zero if column is generated */
        onError = pCol->notNull;
        if( onError==OE_None ) continue; /* No NOT NULL on this column */
        if( i==pTab->iPKey ){
          continue;        /* ROWID is never NULL */
        }
        isGenerated = pCol->colFlags & COLFLAG_GENERATED;
        if( isGenerated && !b2ndPass ){
          nGenerated++;
          continue;        /* Generated columns processed on 2nd pass */
        }
        if( aiChng && aiChng[i]<0 && !isGenerated ){
          /* Do not check NOT NULL on columns that do not change */
          continue;
        }
        if( overrideError!=OE_Default ){
          onError = overrideError;
        }else if( onError==OE_Default ){
          onError = OE_Abort;
        }
        if( onError==OE_Replace ){
          if( b2ndPass        /* REPLACE becomes ABORT on the 2nd pass */
           || pCol->iDflt==0  /* REPLACE is ABORT if no DEFAULT value */
          ){
            testcase( pCol->colFlags & COLFLAG_VIRTUAL );
            testcase( pCol->colFlags & COLFLAG_STORED );
            testcase( pCol->colFlags & COLFLAG_GENERATED );
            onError = OE_Abort;
          }else{
            assert( !isGenerated );
          }
        }else if( b2ndPass && !isGenerated ){
          continue;
        }
        assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
            || onError==OE_Ignore || onError==OE_Replace );
        testcase( i!=sqlite3TableColumnToStorage(pTab, i) );
        iReg = sqlite3TableColumnToStorage(pTab, i) + regNewData + 1;
        switch( onError ){
          case OE_Replace: {
            int addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, iReg);
            VdbeCoverage(v);
            assert( (pCol->colFlags & COLFLAG_GENERATED)==0 );
            nSeenReplace++;
            sqlite3ExprCodeCopy(pParse,
               sqlite3ColumnExpr(pTab, pCol), iReg);
            sqlite3VdbeJumpHere(v, addr1);
            break;
          }
          case OE_Abort:
            sqlite3MayAbort(pParse);
            /* no break */ deliberate_fall_through
          case OE_Rollback:
          case OE_Fail: {
            char *zMsg = sqlite3MPrintf(db, "%s.%s", pTab->zName,
                                        pCol->zCnName);
            testcase( zMsg==0 && db->mallocFailed==0 );
            sqlite3VdbeAddOp3(v, OP_HaltIfNull, SQLITE_CONSTRAINT_NOTNULL,
                              onError, iReg);
            sqlite3VdbeAppendP4(v, zMsg, P4_DYNAMIC);
            sqlite3VdbeChangeP5(v, P5_ConstraintNotNull);
            VdbeCoverage(v);
            break;
          }
          default: {
            assert( onError==OE_Ignore );
            sqlite3VdbeAddOp2(v, OP_IsNull, iReg, ignoreDest);
            VdbeCoverage(v);
            break;
          }
        } /* end switch(onError) */
      } /* end loop i over columns */
      if( nGenerated==0 && nSeenReplace==0 ){
        /* If there are no generated columns with NOT NULL constraints
        ** and no NOT NULL ON CONFLICT REPLACE constraints, then a single
        ** pass is sufficient */
        break;
      }
      if( b2ndPass ) break;  /* Never need more than 2 passes */
      b2ndPass = 1;
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
      if( nSeenReplace>0 && (pTab->tabFlags & TF_HasGenerated)!=0 ){
        /* If any NOT NULL ON CONFLICT REPLACE constraints fired on the
        ** first pass, recomputed values for all generated columns, as
        ** those values might depend on columns affected by the REPLACE.
        */
        sqlite3ComputeGeneratedColumns(pParse, regNewData+1, pTab);
      }
#endif
    } /* end of 2-pass loop */
  } /* end if( has-not-null-constraints ) */

  /* Test all CHECK constraints
  */
#ifndef SQLITE_OMIT_CHECK
  if( pTab->pCheck && (db->flags & SQLITE_IgnoreChecks)==0 ){
    ExprList *pCheck = pTab->pCheck;
    pParse->iSelfTab = -(regNewData+1);
    onError = overrideError!=OE_Default ? overrideError : OE_Abort;
    for(i=0; i<pCheck->nExpr; i++){
      int allOk;
      Expr *pCopy;
      Expr *pExpr = pCheck->a[i].pExpr;
      if( aiChng
       && !sqlite3ExprReferencesUpdatedColumn(pExpr, aiChng, pkChng)
      ){
        /* The check constraints do not reference any of the columns being
        ** updated so there is no point it verifying the check constraint */
        continue;
      }
      if( bAffinityDone==0 ){
        sqlite3TableAffinity(v, pTab, regNewData+1);
        bAffinityDone = 1;
      }
      allOk = sqlite3VdbeMakeLabel(pParse);
      sqlite3VdbeVerifyAbortable(v, onError);
      pCopy = sqlite3ExprDup(db, pExpr, 0);
      if( !db->mallocFailed ){
        sqlite3ExprIfTrue(pParse, pCopy, allOk, SQLITE_JUMPIFNULL);
      }
      sqlite3ExprDelete(db, pCopy);
      if( onError==OE_Ignore ){
        sqlite3VdbeGoto(v, ignoreDest);
      }else{
        char *zName = pCheck->a[i].zEName;
        assert( zName!=0 || pParse->db->mallocFailed );
        if( onError==OE_Replace ) onError = OE_Abort; /* IMP: R-26383-51744 */
        sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_CHECK,
                              onError, zName, P4_TRANSIENT,
                              P5_ConstraintCheck);
      }
      sqlite3VdbeResolveLabel(v, allOk);
    }
    pParse->iSelfTab = 0;
  }
#endif /* !defined(SQLITE_OMIT_CHECK) */

  /* UNIQUE and PRIMARY KEY constraints should be handled in the following
  ** order:
  **
  **   (1)  OE_Update
  **   (2)  OE_Abort, OE_Fail, OE_Rollback, OE_Ignore
  **   (3)  OE_Replace
  **
  ** OE_Fail and OE_Ignore must happen before any changes are made.
  ** OE_Update guarantees that only a single row will change, so it
  ** must happen before OE_Replace.  Technically, OE_Abort and OE_Rollback
  ** could happen in any order, but they are grouped up front for
  ** convenience.
  **
  ** 2018-08-14: Ticket https://sqlite.org/src/info/908f001483982c43
  ** The order of constraints used to have OE_Update as (2) and OE_Abort
  ** and so forth as (1). But apparently PostgreSQL checks the OE_Update
  ** constraint before any others, so it had to be moved.
  **
  ** Constraint checking code is generated in this order:
  **   (A)  The rowid constraint
  **   (B)  Unique index constraints that do not have OE_Replace as their
  **        default conflict resolution strategy
  **   (C)  Unique index that do use OE_Replace by default.
  **
  ** The ordering of (2) and (3) is accomplished by making sure the linked
  ** list of indexes attached to a table puts all OE_Replace indexes last
  ** in the list.  See sqlite3CreateIndex() for where that happens.
  */
  sIdxIter.eType = 0;
  sIdxIter.i = 0;
  sIdxIter.u.ax.aIdx = 0;  /* Silence harmless compiler warning */
  sIdxIter.u.lx.pIdx = pTab->pIndex;
  if( pUpsert ){
    if( pUpsert->pUpsertTarget==0 ){
      /* There is just on ON CONFLICT clause and it has no constraint-target */
      assert( pUpsert->pNextUpsert==0 );
      if( pUpsert->isDoUpdate==0 ){
        /* A single ON CONFLICT DO NOTHING clause, without a constraint-target.
        ** Make all unique constraint resolution be OE_Ignore */
        overrideError = OE_Ignore;
        pUpsert = 0;
      }else{
        /* A single ON CONFLICT DO UPDATE.  Make all resolutions OE_Update */
        overrideError = OE_Update;
      }
    }else if( pTab->pIndex!=0 ){
      /* Otherwise, we'll need to run the IndexListTerm array version of the
      ** iterator to ensure that all of the ON CONFLICT conditions are
      ** checked first and in order. */
      int nIdx, jj;
      u64 nByte;
      Upsert *pTerm;
      u8 *bUsed;
      for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){
         assert( aRegIdx[nIdx]>0 );
      }
      sIdxIter.eType = 1;
      sIdxIter.u.ax.nIdx = nIdx;
      nByte = (sizeof(IndexListTerm)+1)*nIdx + nIdx;
      sIdxIter.u.ax.aIdx = sqlite3DbMallocZero(db, nByte);
      if( sIdxIter.u.ax.aIdx==0 ) return; /* OOM */
      bUsed = (u8*)&sIdxIter.u.ax.aIdx[nIdx];
      pUpsert->pToFree = sIdxIter.u.ax.aIdx;
      for(i=0, pTerm=pUpsert; pTerm; pTerm=pTerm->pNextUpsert){
        if( pTerm->pUpsertTarget==0 ) break;
        if( pTerm->pUpsertIdx==0 ) continue;  /* Skip ON CONFLICT for the IPK */
        jj = 0;
        pIdx = pTab->pIndex;
        while( ALWAYS(pIdx!=0) && pIdx!=pTerm->pUpsertIdx ){
           pIdx = pIdx->pNext;
           jj++;
        }
        if( bUsed[jj] ) continue; /* Duplicate ON CONFLICT clause ignored */
        bUsed[jj] = 1;
        sIdxIter.u.ax.aIdx[i].p = pIdx;
        sIdxIter.u.ax.aIdx[i].ix = jj;
        i++;
      }
      for(jj=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, jj++){
        if( bUsed[jj] ) continue;
        sIdxIter.u.ax.aIdx[i].p = pIdx;
        sIdxIter.u.ax.aIdx[i].ix = jj;
        i++;
      }
      assert( i==nIdx );
    }
  }

  /* Determine if it is possible that triggers (either explicitly coded
  ** triggers or FK resolution actions) might run as a result of deletes
  ** that happen when OE_Replace conflict resolution occurs. (Call these
  ** "replace triggers".)  If any replace triggers run, we will need to
  ** recheck all of the uniqueness constraints after they have all run.
  ** But on the recheck, the resolution is OE_Abort instead of OE_Replace.
  **
  ** If replace triggers are a possibility, then
  **
  **   (1) Allocate register regTrigCnt and initialize it to zero.
  **       That register will count the number of replace triggers that
  **       fire.  Constraint recheck only occurs if the number is positive.
  **   (2) Initialize pTrigger to the list of all DELETE triggers on pTab.
  **   (3) Initialize addrRecheck and lblRecheckOk
  **
  ** The uniqueness rechecking code will create a series of tests to run
  ** in a second pass.  The addrRecheck and lblRecheckOk variables are
  ** used to link together these tests which are separated from each other
  ** in the generate bytecode.
  */
  if( (db->flags & (SQLITE_RecTriggers|SQLITE_ForeignKeys))==0 ){
    /* There are not DELETE triggers nor FK constraints.  No constraint
    ** rechecks are needed. */
    pTrigger = 0;
    regTrigCnt = 0;
  }else{
    if( db->flags&SQLITE_RecTriggers ){
      pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
      regTrigCnt = pTrigger!=0 || sqlite3FkRequired(pParse, pTab, 0, 0);
    }else{
      pTrigger = 0;
      regTrigCnt = sqlite3FkRequired(pParse, pTab, 0, 0);
    }
    if( regTrigCnt ){
      /* At this point regTrigCnt is non-zero if there are DELETE triggers
      ** or FK triggers. But we only care about these things if there is
      ** a chance that a row will be deleted by an ON CONFLICT REPLACE
      ** constraint. So zero regTrigCnt if no such constraint can be found. */
      if( overrideError!=OE_Replace ){
        if( overrideError!=OE_Default ){
          regTrigCnt = 0;
        }else if( pkChng==0 || pPk || pTab->keyConf!=OE_Replace ){
          for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
            if( pIdx->onError==OE_Replace ) break;
          }
          if( pIdx==0 ) regTrigCnt = 0;
        }
      }
    }
    if( regTrigCnt ){
      /* Replace triggers might exist.  Allocate the counter and
      ** initialize it to zero. */
      regTrigCnt = ++pParse->nMem;
      sqlite3VdbeAddOp2(v, OP_Integer, 0, regTrigCnt);
      VdbeComment((v, "trigger count"));
      lblRecheckOk = sqlite3VdbeMakeLabel(pParse);
      addrRecheck = lblRecheckOk;
    }
  }

  /* If rowid is changing, make sure the new rowid does not previously
  ** exist in the table.
  */
  if( pkChng && pPk==0 ){
    int addrRowidOk = sqlite3VdbeMakeLabel(pParse);

    /* Figure out what action to take in case of a rowid collision */
    onError = pTab->keyConf;
    if( overrideError!=OE_Default ){
      onError = overrideError;
    }else if( onError==OE_Default ){
      onError = OE_Abort;
    }

    /* figure out whether or not upsert applies in this case */
    if( pUpsert ){
      pUpsertClause = sqlite3UpsertOfIndex(pUpsert,0);
      if( pUpsertClause!=0 ){
        if( pUpsertClause->isDoUpdate==0 ){
          onError = OE_Ignore;  /* DO NOTHING is the same as INSERT OR IGNORE */
        }else{
          onError = OE_Update;  /* DO UPDATE */
        }
      }
      if( pUpsertClause!=pUpsert ){
        /* The first ON CONFLICT clause has a conflict target other than
        ** the IPK.  We have to jump ahead to that first ON CONFLICT clause
        ** and then come back here and deal with the IPK afterwards */
        upsertIpkDelay = sqlite3VdbeAddOp0(v, OP_Goto);
      }
    }

    /* If the response to a rowid conflict is REPLACE but the response
    ** to some other UNIQUE constraint is FAIL or IGNORE, then we need
    ** to defer the running of the rowid conflict checking until after
    ** the UNIQUE constraints have run.
    */
    if( onError==OE_Replace      /* IPK rule is REPLACE */
     && onError!=overrideError   /* Rules for other constraints are different */
     && pTab->pIndex             /* There exist other constraints */
    ){
      if( upsertIpkDelay ){
        ipkTop = upsertIpkDelay + 1;
        upsertIpkDelay = 0;
      }else{
        ipkTop = sqlite3VdbeAddOp0(v, OP_Goto)+1;
      }
      VdbeComment((v, "defer IPK REPLACE until last"));
    }

    if( isUpdate ){
      /* pkChng!=0 does not mean that the rowid has changed, only that
      ** it might have changed.  Skip the conflict logic below if the rowid
      ** is unchanged. */
      sqlite3VdbeAddOp3(v, OP_Eq, regNewData, addrRowidOk, regOldData);
      sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
      VdbeCoverage(v);
    }

    /* Check to see if the new rowid already exists in the table.  Skip
    ** the following conflict logic if it does not. */
    VdbeNoopComment((v, "uniqueness check for ROWID"));
    sqlite3VdbeVerifyAbortable(v, onError);
    sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, addrRowidOk, regNewData);
    VdbeCoverage(v);

    switch( onError ){
      default: {
        onError = OE_Abort;
        /* no break */ deliberate_fall_through
      }
      case OE_Rollback:
      case OE_Abort:
      case OE_Fail: {
        testcase( onError==OE_Rollback );
        testcase( onError==OE_Abort );
        testcase( onError==OE_Fail );
        sqlite3RowidConstraint(pParse, onError, pTab);
        break;
      }
      case OE_Replace: {
        /* If there are DELETE triggers on this table and the
        ** recursive-triggers flag is set, call GenerateRowDelete() to
        ** remove the conflicting row from the table. This will fire
        ** the triggers and remove both the table and index b-tree entries.
        **
        ** Otherwise, if there are no triggers or the recursive-triggers
        ** flag is not set, but the table has one or more indexes, call
        ** GenerateRowIndexDelete(). This removes the index b-tree entries
        ** only. The table b-tree entry will be replaced by the new entry
        ** when it is inserted. 
        **
        ** If either GenerateRowDelete() or GenerateRowIndexDelete() is called,
        ** also invoke MultiWrite() to indicate that this VDBE may require
        ** statement rollback (if the statement is aborted after the delete
        ** takes place). Earlier versions called sqlite3MultiWrite() regardless,
        ** but being more selective here allows statements like:
        **
        **   REPLACE INTO t(rowid) VALUES($newrowid)
        **
        ** to run without a statement journal if there are no indexes on the
        ** table.
        */
        if( regTrigCnt ){
          sqlite3MultiWrite(pParse);
          sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
                                   regNewData, 1, 0, OE_Replace, 1, -1);
          sqlite3VdbeAddOp2(v, OP_AddImm, regTrigCnt, 1); /* incr trigger cnt */
          nReplaceTrig++;
        }else{
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
          assert( HasRowid(pTab) );
          /* This OP_Delete opcode fires the pre-update-hook only. It does
          ** not modify the b-tree. It is more efficient to let the coming
          ** OP_Insert replace the existing entry than it is to delete the
          ** existing entry and then insert a new one. */
          sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, OPFLAG_ISNOOP);
          sqlite3VdbeAppendP4(v, pTab, P4_TABLE);
#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
          if( pTab->pIndex ){
            sqlite3MultiWrite(pParse);
            sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur,0,-1);
          }
        }
        seenReplace = 1;
        break;
      }
#ifndef SQLITE_OMIT_UPSERT
      case OE_Update: {
        sqlite3UpsertDoUpdate(pParse, pUpsert, pTab, 0, iDataCur);
        /* no break */ deliberate_fall_through
      }
#endif
      case OE_Ignore: {
        testcase( onError==OE_Ignore );
        sqlite3VdbeGoto(v, ignoreDest);
        break;
      }
    }
    sqlite3VdbeResolveLabel(v, addrRowidOk);
    if( ipkTop ){
      ipkBottom = sqlite3VdbeAddOp0(v, OP_Goto);
      sqlite3VdbeJumpHere(v, ipkTop-1);
    }else if( pUpsert && pUpsertClause!=pUpsert ){
      upsertIpkReturn = sqlite3VdbeAddOp0(v, OP_Goto);
    }
  }

  /* Test all UNIQUE constraints by creating entries for each UNIQUE
  ** index and making sure that duplicate entries do not already exist.
  ** Compute the revised record entries for indices as we go.
  **
  ** This loop also handles the case of the PRIMARY KEY index for a
  ** WITHOUT ROWID table.
  */
  for(pIdx = indexIteratorFirst(&sIdxIter, &ix);
      pIdx;
      pIdx = indexIteratorNext(&sIdxIter, &ix)
  ){
    int regIdx;          /* Range of registers holding content for pIdx */
    int regR;            /* Range of registers holding conflicting PK */
    int iThisCur;        /* Cursor for this UNIQUE index */
    int addrUniqueOk;    /* Jump here if the UNIQUE constraint is satisfied */
    int addrConflictCk;  /* First opcode in the conflict check logic */
    int nConflictCk;     /* Number of opcodes in conflict check logic */

    if( aRegIdx[ix]==0 ) continue;  /* Skip indices that do not change */
    if( pUpsert ){
      pUpsertClause = sqlite3UpsertOfIndex(pUpsert, pIdx);
      if( upsertIpkDelay && pUpsertClause==pUpsert ){
        sqlite3VdbeJumpHere(v, upsertIpkDelay);
      }
    }
    addrUniqueOk = sqlite3VdbeMakeLabel(pParse);
    if( bAffinityDone==0 ){
      sqlite3TableAffinity(v, pTab, regNewData+1);
      bAffinityDone = 1;
    }
    VdbeNoopComment((v, "prep index %s", pIdx->zName));
    iThisCur = iIdxCur+ix;


    /* Skip partial indices for which the WHERE clause is not true */
    if( pIdx->pPartIdxWhere ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, aRegIdx[ix]);
      pParse->iSelfTab = -(regNewData+1);
      sqlite3ExprIfFalseDup(pParse, pIdx->pPartIdxWhere, addrUniqueOk,
                            SQLITE_JUMPIFNULL);
      pParse->iSelfTab = 0;
    }

    /* Create a record for this index entry as it should appear after
    ** the insert or update.  Store that record in the aRegIdx[ix] register
    */
    regIdx = aRegIdx[ix]+1;
    for(i=0; i<pIdx->nColumn; i++){
      int iField = pIdx->aiColumn[i];
      int x;
      if( iField==XN_EXPR ){
        pParse->iSelfTab = -(regNewData+1);
        sqlite3ExprCodeCopy(pParse, pIdx->aColExpr->a[i].pExpr, regIdx+i);
        pParse->iSelfTab = 0;
        VdbeComment((v, "%s column %d", pIdx->zName, i));
      }else if( iField==XN_ROWID || iField==pTab->iPKey ){
        x = regNewData;
        sqlite3VdbeAddOp2(v, OP_IntCopy, x, regIdx+i);
        VdbeComment((v, "rowid"));
      }else{
        testcase( sqlite3TableColumnToStorage(pTab, iField)!=iField );
        x = sqlite3TableColumnToStorage(pTab, iField) + regNewData + 1;
        sqlite3VdbeAddOp2(v, OP_SCopy, x, regIdx+i);
        VdbeComment((v, "%s", pTab->aCol[iField].zCnName));
      }
    }
    sqlite3VdbeAddOp3(v, OP_MakeRecord, regIdx, pIdx->nColumn, aRegIdx[ix]);
    VdbeComment((v, "for %s", pIdx->zName));
#ifdef SQLITE_ENABLE_NULL_TRIM
    if( pIdx->idxType==SQLITE_IDXTYPE_PRIMARYKEY ){
      sqlite3SetMakeRecordP5(v, pIdx->pTable);
    }
#endif
    sqlite3VdbeReleaseRegisters(pParse, regIdx, pIdx->nColumn, 0, 0);

    /* In an UPDATE operation, if this index is the PRIMARY KEY index
    ** of a WITHOUT ROWID table and there has been no change the
    ** primary key, then no collision is possible.  The collision detection
    ** logic below can all be skipped. */
    if( isUpdate && pPk==pIdx && pkChng==0 ){
      sqlite3VdbeResolveLabel(v, addrUniqueOk);
      continue;
    }

    /* Find out what action to take in case there is a uniqueness conflict */
    onError = pIdx->onError;
    if( onError==OE_None ){
      sqlite3VdbeResolveLabel(v, addrUniqueOk);
      continue;  /* pIdx is not a UNIQUE index */
    }
    if( overrideError!=OE_Default ){
      onError = overrideError;
    }else if( onError==OE_Default ){
      onError = OE_Abort;
    }

    /* Figure out if the upsert clause applies to this index */
    if( pUpsertClause ){
      if( pUpsertClause->isDoUpdate==0 ){
        onError = OE_Ignore;  /* DO NOTHING is the same as INSERT OR IGNORE */
      }else{
        onError = OE_Update;  /* DO UPDATE */
      }
    }

    /* Collision detection may be omitted if all of the following are true:
    **   (1) The conflict resolution algorithm is REPLACE
    **   (2) The table is a WITHOUT ROWID table
    **   (3) There are no secondary indexes on the table
    **   (4) No delete triggers need to be fired if there is a conflict
    **   (5) No FK constraint counters need to be updated if a conflict occurs.
    **
    ** This is not possible for ENABLE_PREUPDATE_HOOK builds, as the row
    ** must be explicitly deleted in order to ensure any pre-update hook
    ** is invoked.  */
    assert( IsOrdinaryTable(pTab) );
#ifndef SQLITE_ENABLE_PREUPDATE_HOOK
    if( (ix==0 && pIdx->pNext==0)                   /* Condition 3 */
     && pPk==pIdx                                   /* Condition 2 */
     && onError==OE_Replace                         /* Condition 1 */
     && ( 0==(db->flags&SQLITE_RecTriggers) ||      /* Condition 4 */
          0==sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0))
     && ( 0==(db->flags&SQLITE_ForeignKeys) ||      /* Condition 5 */
         (0==pTab->u.tab.pFKey && 0==sqlite3FkReferences(pTab)))
    ){
      sqlite3VdbeResolveLabel(v, addrUniqueOk);
      continue;
    }
#endif /* ifndef SQLITE_ENABLE_PREUPDATE_HOOK */

    /* Check to see if the new index entry will be unique */
    sqlite3VdbeVerifyAbortable(v, onError);
    addrConflictCk =
      sqlite3VdbeAddOp4Int(v, OP_NoConflict, iThisCur, addrUniqueOk,
                           regIdx, pIdx->nKeyCol); VdbeCoverage(v);

    /* Generate code to handle collisions */
    regR = pIdx==pPk ? regIdx : sqlite3GetTempRange(pParse, nPkField);
    if( isUpdate || onError==OE_Replace ){
      if( HasRowid(pTab) ){
        sqlite3VdbeAddOp2(v, OP_IdxRowid, iThisCur, regR);
        /* Conflict only if the rowid of the existing index entry
        ** is different from old-rowid */
        if( isUpdate ){
          sqlite3VdbeAddOp3(v, OP_Eq, regR, addrUniqueOk, regOldData);
          sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
          VdbeCoverage(v);
        }
      }else{
        int x;
        /* Extract the PRIMARY KEY from the end of the index entry and
        ** store it in registers regR..regR+nPk-1 */
        if( pIdx!=pPk ){
          for(i=0; i<pPk->nKeyCol; i++){
            assert( pPk->aiColumn[i]>=0 );
            x = sqlite3TableColumnToIndex(pIdx, pPk->aiColumn[i]);
            sqlite3VdbeAddOp3(v, OP_Column, iThisCur, x, regR+i);
            VdbeComment((v, "%s.%s", pTab->zName,
                         pTab->aCol[pPk->aiColumn[i]].zCnName));
          }
        }
        if( isUpdate ){
          /* If currently processing the PRIMARY KEY of a WITHOUT ROWID
          ** table, only conflict if the new PRIMARY KEY values are actually
          ** different from the old.  See TH3 withoutrowid04.test.
          **
          ** For a UNIQUE index, only conflict if the PRIMARY KEY values
          ** of the matched index row are different from the original PRIMARY
          ** KEY values of this row before the update.  */
          int addrJump = sqlite3VdbeCurrentAddr(v)+pPk->nKeyCol;
          int op = OP_Ne;
          int regCmp = (IsPrimaryKeyIndex(pIdx) ? regIdx : regR);
 
          for(i=0; i<pPk->nKeyCol; i++){
            char *p4 = (char*)sqlite3LocateCollSeq(pParse, pPk->azColl[i]);
            x = pPk->aiColumn[i];
            assert( x>=0 );
            if( i==(pPk->nKeyCol-1) ){
              addrJump = addrUniqueOk;
              op = OP_Eq;
            }
            x = sqlite3TableColumnToStorage(pTab, x);
            sqlite3VdbeAddOp4(v, op,
                regOldData+1+x, addrJump, regCmp+i, p4, P4_COLLSEQ
            );
            sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
            VdbeCoverageIf(v, op==OP_Eq);
            VdbeCoverageIf(v, op==OP_Ne);
          }
        }
      }
    }

    nConflictCk = sqlite3VdbeCurrentAddr(v) - addrConflictCk;
    assert( nConflictCk>0 || db->mallocFailed );
    testcase( nConflictCk<=0 );
    testcase( nConflictCk>1 );

    /* Generate code that executes if the new index entry is not unique */
    assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
        || onError==OE_Ignore || onError==OE_Replace || onError==OE_Update );
    switch( onError ){
      case OE_Rollback:
      case OE_Abort:
      case OE_Fail: {
        testcase( onError==OE_Rollback );
        testcase( onError==OE_Abort );
        testcase( onError==OE_Fail );
        sqlite3UniqueConstraint(pParse, onError, pIdx);
        break;
      }
#ifndef SQLITE_OMIT_UPSERT
      case OE_Update: {
        sqlite3UpsertDoUpdate(pParse, pUpsert, pTab, pIdx, iIdxCur+ix);
        /* no break */ deliberate_fall_through
      }
#endif
      case OE_Ignore: {
        testcase( onError==OE_Ignore );
        sqlite3VdbeGoto(v, ignoreDest);
        break;
      }
      default: {
        assert( onError==OE_Replace );
        if( regTrigCnt ){
          sqlite3MultiWrite(pParse);
          nReplaceTrig++;
        }
        if( pTrigger && isUpdate ){
          sqlite3VdbeAddOp1(v, OP_CursorLock, iDataCur);
        }
        sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
            regR, nPkField, 0, OE_Replace,
            (pIdx==pPk ? ONEPASS_SINGLE : ONEPASS_OFF), iThisCur);
        if( pTrigger && isUpdate ){
          sqlite3VdbeAddOp1(v, OP_CursorUnlock, iDataCur);
        }
        seenReplace = 1;
        break;
      }
    }
    if( regTrigCnt ){
      int addrBypass;  /* Jump destination to bypass recheck logic */

      sqlite3VdbeAddOp2(v, OP_AddImm, regTrigCnt, 1); /* incr trigger cnt */
      addrBypass = sqlite3VdbeAddOp0(v, OP_Goto);  /* Bypass recheck */
      VdbeComment((v, "bypass recheck"));

      /* Here we insert code that will be invoked after all constraint
      ** checks have run, if and only if one or more replace triggers
      ** fired. */
      sqlite3VdbeResolveLabel(v, lblRecheckOk);
      lblRecheckOk = sqlite3VdbeMakeLabel(pParse);
      if( pIdx->pPartIdxWhere ){
        /* Bypass the recheck if this partial index is not defined
        ** for the current row */
        sqlite3VdbeAddOp2(v, OP_IsNull, regIdx-1, lblRecheckOk);
        VdbeCoverage(v);
      }
      /* Copy the constraint check code from above, except change
      ** the constraint-ok jump destination to be the address of
      ** the next retest block */
      while( nConflictCk>0 ){
        VdbeOp x;    /* Conflict check opcode to copy */
        /* The sqlite3VdbeAddOp4() call might reallocate the opcode array.
        ** Hence, make a complete copy of the opcode, rather than using
        ** a pointer to the opcode. */
        x = *sqlite3VdbeGetOp(v, addrConflictCk);
        if( x.opcode!=OP_IdxRowid ){
          int p2;      /* New P2 value for copied conflict check opcode */
          const char *zP4;
          if( sqlite3OpcodeProperty[x.opcode]&OPFLG_JUMP ){
            p2 = lblRecheckOk;
          }else{
            p2 = x.p2;
          }
          zP4 = x.p4type==P4_INT32 ? SQLITE_INT_TO_PTR(x.p4.i) : x.p4.z;
          sqlite3VdbeAddOp4(v, x.opcode, x.p1, p2, x.p3, zP4, x.p4type);
          sqlite3VdbeChangeP5(v, x.p5);
          VdbeCoverageIf(v, p2!=x.p2);
        }
        nConflictCk--;
        addrConflictCk++;
      }
      /* If the retest fails, issue an abort */
      sqlite3UniqueConstraint(pParse, OE_Abort, pIdx);

      sqlite3VdbeJumpHere(v, addrBypass); /* Terminate the recheck bypass */
    }
    sqlite3VdbeResolveLabel(v, addrUniqueOk);
    if( regR!=regIdx ) sqlite3ReleaseTempRange(pParse, regR, nPkField);
    if( pUpsertClause
     && upsertIpkReturn
     && sqlite3UpsertNextIsIPK(pUpsertClause)
    ){
      sqlite3VdbeGoto(v, upsertIpkDelay+1);
      sqlite3VdbeJumpHere(v, upsertIpkReturn);
      upsertIpkReturn = 0;
    }
  }

  /* If the IPK constraint is a REPLACE, run it last */
  if( ipkTop ){
    sqlite3VdbeGoto(v, ipkTop);
    VdbeComment((v, "Do IPK REPLACE"));
    assert( ipkBottom>0 );
    sqlite3VdbeJumpHere(v, ipkBottom);
  }

  /* Recheck all uniqueness constraints after replace triggers have run */
  testcase( regTrigCnt!=0 && nReplaceTrig==0 );
  assert( regTrigCnt!=0 || nReplaceTrig==0 );
  if( nReplaceTrig ){
    sqlite3VdbeAddOp2(v, OP_IfNot, regTrigCnt, lblRecheckOk);VdbeCoverage(v);
    if( !pPk ){
      if( isUpdate ){
        sqlite3VdbeAddOp3(v, OP_Eq, regNewData, addrRecheck, regOldData);
        sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
        VdbeCoverage(v);
      }
      sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, addrRecheck, regNewData);
      VdbeCoverage(v);
      sqlite3RowidConstraint(pParse, OE_Abort, pTab);
    }else{
      sqlite3VdbeGoto(v, addrRecheck);
    }
  }
  if( regTrigCnt ) sqlite3VdbeResolveLabel(v, lblRecheckOk);

  /* Generate the table record */
  if( HasRowid(pTab) ){
    int regRec = aRegIdx[ix];
    sqlite3VdbeAddOp3(v, OP_MakeRecord, regNewData+1, pTab->nNVCol, regRec);
    sqlite3SetMakeRecordP5(v, pTab);
    if( !bAffinityDone ){
      sqlite3TableAffinity(v, pTab, 0);
    }
  }

  *pbMayReplace = seenReplace;
  VdbeModuleComment((v, "END: GenCnstCks(%d)", seenReplace));
}

#ifdef SQLITE_ENABLE_NULL_TRIM
/*
** Change the P5 operand on the last opcode (which should be an OP_MakeRecord)
** to be the number of columns in table pTab that must not be NULL-trimmed.
**
** Or if no columns of pTab may be NULL-trimmed, leave P5 at zero.
*/
void sqlite3SetMakeRecordP5(Vdbe *v, Table *pTab){
  u16 i;

  /* Records with omitted columns are only allowed for schema format
  ** version 2 and later (SQLite version 3.1.4, 2005-02-20). */
  if( pTab->pSchema->file_format<2 ) return;

  for(i=pTab->nCol-1; i>0; i--){
    if( pTab->aCol[i].iDflt!=0 ) break;
    if( pTab->aCol[i].colFlags & COLFLAG_PRIMKEY ) break;
  }
  sqlite3VdbeChangeP5(v, i+1);
}
#endif

/*
** Table pTab is a WITHOUT ROWID table that is being written to. The cursor
** number is iCur, and register regData contains the new record for the
** PK index. This function adds code to invoke the pre-update hook,
** if one is registered.
*/
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
static void codeWithoutRowidPreupdate(
  Parse *pParse,                  /* Parse context */
  Table *pTab,                    /* Table being updated */
  int iCur,                       /* Cursor number for table */
  int regData                     /* Data containing new record */
){
  Vdbe *v = pParse->pVdbe;
  int r = sqlite3GetTempReg(pParse);
  assert( !HasRowid(pTab) );
  assert( 0==(pParse->db->mDbFlags & DBFLAG_Vacuum) || CORRUPT_DB );
  sqlite3VdbeAddOp2(v, OP_Integer, 0, r);
  sqlite3VdbeAddOp4(v, OP_Insert, iCur, regData, r, (char*)pTab, P4_TABLE);
  sqlite3VdbeChangeP5(v, OPFLAG_ISNOOP);
  sqlite3ReleaseTempReg(pParse, r);
}
#else
# define codeWithoutRowidPreupdate(a,b,c,d)
#endif

/*
** This routine generates code to finish the INSERT or UPDATE operation
** that was started by a prior call to sqlite3GenerateConstraintChecks.
** A consecutive range of registers starting at regNewData contains the
** rowid and the content to be inserted.
**
** The arguments to this routine should be the same as the first six
** arguments to sqlite3GenerateConstraintChecks.
*/
void sqlite3CompleteInsertion(
  Parse *pParse,      /* The parser context */
  Table *pTab,        /* the table into which we are inserting */
  int iDataCur,       /* Cursor of the canonical data source */
  int iIdxCur,        /* First index cursor */
  int regNewData,     /* Range of content */
  int *aRegIdx,       /* Register used by each index.  0 for unused indices */
  int update_flags,   /* True for UPDATE, False for INSERT */
  int appendBias,     /* True if this is likely to be an append */
  int useSeekResult   /* True to set the USESEEKRESULT flag on OP_[Idx]Insert */
){
  Vdbe *v;            /* Prepared statements under construction */
  Index *pIdx;        /* An index being inserted or updated */
  u8 pik_flags;       /* flag values passed to the btree insert */
  int i;              /* Loop counter */

  assert( update_flags==0
       || update_flags==OPFLAG_ISUPDATE
       || update_flags==(OPFLAG_ISUPDATE|OPFLAG_SAVEPOSITION)
  );

  v = pParse->pVdbe;
  assert( v!=0 );
  assert( !IsView(pTab) );  /* This table is not a VIEW */
  for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
    /* All REPLACE indexes are at the end of the list */
    assert( pIdx->onError!=OE_Replace
         || pIdx->pNext==0
         || pIdx->pNext->onError==OE_Replace );
    if( aRegIdx[i]==0 ) continue;
    if( pIdx->pPartIdxWhere || (update_flags && pIdx->bHasExpr) ){
      /* If this is a partial index, or an UPDATE of an index on an
      ** expression, then the record register may be set to NULL to indicate
      ** that no record should be inserted into this index. */
      sqlite3VdbeAddOp2(v, OP_IsNull, aRegIdx[i], sqlite3VdbeCurrentAddr(v)+2);
      VdbeCoverage(v);
    }
    pik_flags = (useSeekResult ? OPFLAG_USESEEKRESULT : 0);
    if( IsPrimaryKeyIndex(pIdx) && !HasRowid(pTab) ){
      pik_flags |= OPFLAG_NCHANGE;
      pik_flags |= (update_flags & OPFLAG_SAVEPOSITION);
      if( update_flags==0 ){
        codeWithoutRowidPreupdate(pParse, pTab, iIdxCur+i, aRegIdx[i]);
      }
    }
    sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iIdxCur+i, aRegIdx[i],
                         aRegIdx[i]+1,
                         pIdx->uniqNotNull ? pIdx->nKeyCol: pIdx->nColumn);
    sqlite3VdbeChangeP5(v, pik_flags);
  }
  if( !HasRowid(pTab) ) return;
  if( pParse->nested ){
    pik_flags = 0;
  }else{
    pik_flags = OPFLAG_NCHANGE;
    pik_flags |= (update_flags?update_flags:OPFLAG_LASTROWID);
  }
  if( appendBias ){
    pik_flags |= OPFLAG_APPEND;
  }
  if( useSeekResult ){
    pik_flags |= OPFLAG_USESEEKRESULT;
  }
  sqlite3VdbeAddOp3(v, OP_Insert, iDataCur, aRegIdx[i], regNewData);
  if( !pParse->nested ){
    sqlite3VdbeAppendP4(v, pTab, P4_TABLE);
  }
  sqlite3VdbeChangeP5(v, pik_flags);
}

/*
** Allocate cursors for the pTab table and all its indices and generate
** code to open and initialized those cursors.
**
** The cursor for the object that contains the complete data (normally
** the table itself, but the PRIMARY KEY index in the case of a WITHOUT
** ROWID table) is returned in *piDataCur.  The first index cursor is
** returned in *piIdxCur.  The number of indices is returned.
**
** Use iBase as the first cursor (either the *piDataCur for rowid tables
** or the first index for WITHOUT ROWID tables) if it is non-negative.
** If iBase is negative, then allocate the next available cursor.
**
** For a rowid table, *piDataCur will be exactly one less than *piIdxCur.
** For a WITHOUT ROWID table, *piDataCur will be somewhere in the range
** of *piIdxCurs, depending on where the PRIMARY KEY index appears on the
** pTab->pIndex list.
**
** If pTab is a virtual table, then this routine is a no-op and the
** *piDataCur and *piIdxCur values are left uninitialized.
*/
int sqlite3OpenTableAndIndices(
  Parse *pParse,   /* Parsing context */
  Table *pTab,     /* Table to be opened */
  int op,          /* OP_OpenRead or OP_OpenWrite */
  u8 p5,           /* P5 value for OP_Open* opcodes (except on WITHOUT ROWID) */
  int iBase,       /* Use this for the table cursor, if there is one */
  u8 *aToOpen,     /* If not NULL: boolean for each table and index */
  int *piDataCur,  /* Write the database source cursor number here */
  int *piIdxCur    /* Write the first index cursor number here */
){
  int i;
  int iDb;
  int iDataCur;
  Index *pIdx;
  Vdbe *v;

  assert( op==OP_OpenRead || op==OP_OpenWrite );
  assert( op==OP_OpenWrite || p5==0 );
  assert( piDataCur!=0 );
  assert( piIdxCur!=0 );
  if( IsVirtual(pTab) ){
    /* This routine is a no-op for virtual tables. Leave the output
    ** variables *piDataCur and *piIdxCur set to illegal cursor numbers
    ** for improved error detection. */
    *piDataCur = *piIdxCur = -999;
    return 0;
  }
  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
  v = pParse->pVdbe;
  assert( v!=0 );
  if( iBase<0 ) iBase = pParse->nTab;
  iDataCur = iBase++;
  *piDataCur = iDataCur;
  if( HasRowid(pTab) && (aToOpen==0 || aToOpen[0]) ){
    sqlite3OpenTable(pParse, iDataCur, iDb, pTab, op);
  }else if( pParse->db->noSharedCache==0 ){
    sqlite3TableLock(pParse, iDb, pTab->tnum, op==OP_OpenWrite, pTab->zName);
  }
  *piIdxCur = iBase;
  for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
    int iIdxCur = iBase++;
    assert( pIdx->pSchema==pTab->pSchema );
    if( IsPrimaryKeyIndex(pIdx) && !HasRowid(pTab) ){
      *piDataCur = iIdxCur;
      p5 = 0;
    }
    if( aToOpen==0 || aToOpen[i+1] ){
      sqlite3VdbeAddOp3(v, op, iIdxCur, pIdx->tnum, iDb);
      sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
      sqlite3VdbeChangeP5(v, p5);
      VdbeComment((v, "%s", pIdx->zName));
    }
  }
  if( iBase>pParse->nTab ) pParse->nTab = iBase;
  return i;
}


#ifdef SQLITE_TEST
/*
** The following global variable is incremented whenever the
** transfer optimization is used.  This is used for testing
** purposes only - to make sure the transfer optimization really
** is happening when it is supposed to.
*/
int sqlite3_xferopt_count;
#endif /* SQLITE_TEST */


#ifndef SQLITE_OMIT_XFER_OPT
/*
** Check to see if index pSrc is compatible as a source of data
** for index pDest in an insert transfer optimization.  The rules
** for a compatible index:
**
**    *   The index is over the same set of columns
**    *   The same DESC and ASC markings occurs on all columns
**    *   The same onError processing (OE_Abort, OE_Ignore, etc)
**    *   The same collating sequence on each column
**    *   The index has the exact same WHERE clause
*/
static int xferCompatibleIndex(Index *pDest, Index *pSrc){
  int i;
  assert( pDest && pSrc );
  assert( pDest->pTable!=pSrc->pTable );
  if( pDest->nKeyCol!=pSrc->nKeyCol || pDest->nColumn!=pSrc->nColumn ){
    return 0;   /* Different number of columns */
  }
  if( pDest->onError!=pSrc->onError ){
    return 0;   /* Different conflict resolution strategies */
  }
  for(i=0; i<pSrc->nKeyCol; i++){
    if( pSrc->aiColumn[i]!=pDest->aiColumn[i] ){
      return 0;   /* Different columns indexed */
    }
    if( pSrc->aiColumn[i]==XN_EXPR ){
      assert( pSrc->aColExpr!=0 && pDest->aColExpr!=0 );
      if( sqlite3ExprCompare(0, pSrc->aColExpr->a[i].pExpr,
                             pDest->aColExpr->a[i].pExpr, -1)!=0 ){
        return 0;   /* Different expressions in the index */
      }
    }
    if( pSrc->aSortOrder[i]!=pDest->aSortOrder[i] ){
      return 0;   /* Different sort orders */
    }
    if( sqlite3_stricmp(pSrc->azColl[i],pDest->azColl[i])!=0 ){
      return 0;   /* Different collating sequences */
    }
  }
  if( sqlite3ExprCompare(0, pSrc->pPartIdxWhere, pDest->pPartIdxWhere, -1) ){
    return 0;     /* Different WHERE clauses */
  }

  /* If no test above fails then the indices must be compatible */
  return 1;
}

/*
** Examine an expression node and abort if it references the ROWID.
** This is a Walker callback used by xferCompatibleCheck()
*/
static int xferCheckRowid(Walker *pWalk, Expr *pExpr){
  if( pExpr->op==TK_COLUMN && pExpr->iColumn<0 ){
    pWalk->eCode = 1;
    return WRC_Abort;
  }else{
    return WRC_Continue;
  }
}

/*
** Analyze CHECK constraints on the source and destination tables and
** return true if those CHECK constraints are compatible with the
** xfer-optimization.
**
**    *  The pDest and pSrc tables must have identical CHECK constraints.
**
**    *  If the destination table, pDest, does not have an
**       INTEGER PRIMARY KEY column, then no CHECK constraint may
**       referenced the ROWID.  (See forum post 2026-05-11T13:15:57Z)
*/
static int xferCompatibleCheck(Table *pDest, Table *pSrc){
  if( sqlite3ExprListCompare(pSrc->pCheck,pDest->pCheck,-1) ){
    return 0;
  }
  if( pDest->iPKey<0 ){
    Walker w;
    memset(&w, 0, sizeof(w));
    w.xExprCallback = xferCheckRowid;
    sqlite3WalkExprList(&w,pDest->pCheck);
    if( w.eCode ) return 0;
  }
  return 1;
}

/*
** Attempt the transfer optimization on INSERTs of the form
**
**     INSERT INTO tab1 SELECT * FROM tab2;
**
** The xfer optimization transfers raw records from tab2 over to tab1. 
** Columns are not decoded and reassembled, which greatly improves
** performance.  Raw index records are transferred in the same way.
**
** The xfer optimization is only attempted if tab1 and tab2 are compatible.
** There are lots of rules for determining compatibility - see comments
** embedded in the code for details.
**
** This routine returns TRUE if the optimization is guaranteed to be used.
** Sometimes the xfer optimization will only work if the destination table
** is empty - a factor that can only be determined at run-time.  In that
** case, this routine generates code for the xfer optimization but also
** does a test to see if the destination table is empty and jumps over the
** xfer optimization code if the test fails.  In that case, this routine
** returns FALSE so that the caller will know to go ahead and generate
** an unoptimized transfer.  This routine also returns FALSE if there
** is no chance that the xfer optimization can be applied.
**
** This optimization is particularly useful at making VACUUM run faster.
*/
static int xferOptimization(
  Parse *pParse,        /* Parser context */
  Table *pDest,         /* The table we are inserting into */
  Select *pSelect,      /* A SELECT statement to use as the data source */
  int onError,          /* How to handle constraint errors */
  int iDbDest           /* The database of pDest */
){
  sqlite3 *db = pParse->db;
  ExprList *pEList;                /* The result set of the SELECT */
  Table *pSrc;                     /* The table in the FROM clause of SELECT */
  Index *pSrcIdx, *pDestIdx;       /* Source and destination indices */
  SrcItem *pItem;                  /* An element of pSelect->pSrc */
  int i;                           /* Loop counter */
  int iDbSrc;                      /* The database of pSrc */
  int iSrc, iDest;                 /* Cursors from source and destination */
  int addr1, addr2;                /* Loop addresses */
  int emptyDestTest = 0;           /* Address of test for empty pDest */
  int emptySrcTest = 0;            /* Address of test for empty pSrc */
  Vdbe *v;                         /* The VDBE we are building */
  int regAutoinc;                  /* Memory register used by AUTOINC */
  int destHasUniqueIdx = 0;        /* True if pDest has a UNIQUE index */
  int regData, regRowid;           /* Registers holding data and rowid */

  assert( pSelect!=0 );
  if( pParse->pWith || pSelect->pWith ){
    /* Do not attempt to process this query if there are an WITH clauses
    ** attached to it. Proceeding may generate a false "no such table: xxx"
    ** error if pSelect reads from a CTE named "xxx".  */
    return 0;
  }
#ifndef SQLITE_OMIT_VIRTUALTABLE
  if( IsVirtual(pDest) ){
    return 0;   /* tab1 must not be a virtual table */
  }
#endif
  if( onError==OE_Default ){
    if( pDest->iPKey>=0 ) onError = pDest->keyConf;
    if( onError==OE_Default ) onError = OE_Abort;
  }
  assert(pSelect->pSrc);   /* allocated even if there is no FROM clause */
  if( pSelect->pSrc->nSrc!=1 ){
    return 0;   /* FROM clause must have exactly one term */
  }
  if( pSelect->pSrc->a[0].fg.isSubquery ){
    return 0;   /* FROM clause cannot contain a subquery */
  }
  if( pSelect->pWhere ){
    return 0;   /* SELECT may not have a WHERE clause */
  }
  if( pSelect->pOrderBy ){
    return 0;   /* SELECT may not have an ORDER BY clause */
  }
  /* Do not need to test for a HAVING clause.  If HAVING is present but
  ** there is no ORDER BY, we will get an error. */
  if( pSelect->pGroupBy ){
    return 0;   /* SELECT may not have a GROUP BY clause */
  }
  if( pSelect->pLimit ){
    return 0;   /* SELECT may not have a LIMIT clause */
  }
  if( pSelect->pPrior ){
    return 0;   /* SELECT may not be a compound query */
  }
  if( pSelect->selFlags & SF_Distinct ){
    return 0;   /* SELECT may not be DISTINCT */
  }
  pEList = pSelect->pEList;
  assert( pEList!=0 );
  if( pEList->nExpr!=1 ){
    return 0;   /* The result set must have exactly one column */
  }
  assert( pEList->a[0].pExpr );
  if( pEList->a[0].pExpr->op!=TK_ASTERISK ){
    return 0;   /* The result set must be the special operator "*" */
  }

  /* At this point we have established that the statement is of the
  ** correct syntactic form to participate in this optimization.  Now
  ** we have to check the semantics.
  */
  pItem = pSelect->pSrc->a;
  pSrc = sqlite3LocateTableItem(pParse, 0, pItem);
  if( pSrc==0 ){
    return 0;   /* FROM clause does not contain a real table */
  }
  if( pSrc->tnum==pDest->tnum && pSrc->pSchema==pDest->pSchema ){
    testcase( pSrc!=pDest ); /* Possible due to bad sqlite_schema.rootpage */
    return 0;   /* tab1 and tab2 may not be the same table */
  }
  if( HasRowid(pDest)!=HasRowid(pSrc) ){
    return 0;   /* source and destination must both be WITHOUT ROWID or not */
  }
  if( !IsOrdinaryTable(pSrc) ){
    return 0;   /* tab2 may not be a view or virtual table */
  }
  if( pDest->nCol!=pSrc->nCol ){
    return 0;   /* Number of columns must be the same in tab1 and tab2 */
  }
  if( pDest->iPKey!=pSrc->iPKey ){
    return 0;   /* Both tables must have the same INTEGER PRIMARY KEY */
  }
  if( (pDest->tabFlags & TF_Strict)!=0 ){
    if( (pSrc->tabFlags & TF_Strict)==0 ){
      return 0;  /* Cannot feed from a non-strict into a strict table */
    }
    for(i=0; i<pDest->nCol; i++){
      unsigned eDestType = pDest->aCol[i].eCType;
      unsigned eSrcType = pSrc->aCol[i].eCType;
      if( eDestType==COLTYPE_ANY ) continue;
      if( eDestType==eSrcType ) continue;
      if( eDestType==COLTYPE_INT && eSrcType==COLTYPE_INTEGER ) continue;
      if( eDestType==COLTYPE_INTEGER && eSrcType==COLTYPE_INT ) continue;
      return 0; /* Incompatible types in source and destination */
    }
  }
  for(i=0; i<pDest->nCol; i++){
    Column *pDestCol = &pDest->aCol[i];
    Column *pSrcCol = &pSrc->aCol[i];
#ifdef SQLITE_ENABLE_HIDDEN_COLUMNS
    if( (db->mDbFlags & DBFLAG_Vacuum)==0
     && (pDestCol->colFlags | pSrcCol->colFlags) & COLFLAG_HIDDEN
    ){
      return 0;    /* Neither table may have __hidden__ columns */
    }
#endif
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
    /* Even if tables t1 and t2 have identical schemas, if they contain
    ** generated columns, then this statement is semantically incorrect:
    **
    **     INSERT INTO t2 SELECT * FROM t1;
    **
    ** The reason is that generated column values are returned by the
    ** the SELECT statement on the right but the INSERT statement on the
    ** left wants them to be omitted.
    **
    ** Nevertheless, this is a useful notational shorthand to tell SQLite
    ** to do a bulk transfer all of the content from t1 over to t2.
    **
    ** We could, in theory, disable this (except for internal use by the
    ** VACUUM command where it is actually needed).  But why do that?  It
    ** seems harmless enough, and provides a useful service.
    */
    if( (pDestCol->colFlags & COLFLAG_GENERATED) !=
        (pSrcCol->colFlags & COLFLAG_GENERATED) ){
      return 0;    /* Both columns have the same generated-column type */
    }
    /* But the transfer is only allowed if both the source and destination
    ** tables have the exact same expressions for generated columns.
    ** This requirement could be relaxed for VIRTUAL columns, I suppose.
    */
    if( (pDestCol->colFlags & COLFLAG_GENERATED)!=0 ){
      if( sqlite3ExprCompare(0,
             sqlite3ColumnExpr(pSrc, pSrcCol),
             sqlite3ColumnExpr(pDest, pDestCol), -1)!=0 ){
        testcase( pDestCol->colFlags & COLFLAG_VIRTUAL );
        testcase( pDestCol->colFlags & COLFLAG_STORED );
        return 0;  /* Different generator expressions */
      }
    }
#endif
    if( pDestCol->affinity!=pSrcCol->affinity ){
      return 0;    /* Affinity must be the same on all columns */
    }
    if( sqlite3_stricmp(sqlite3ColumnColl(pDestCol),
                        sqlite3ColumnColl(pSrcCol))!=0 ){
      return 0;    /* Collating sequence must be the same on all columns */
    }
    if( pDestCol->notNull && !pSrcCol->notNull ){
      return 0;    /* tab2 must be NOT NULL if tab1 is */
    }
    /* Default values for second and subsequent columns need to match. */
    if( (pDestCol->colFlags & COLFLAG_GENERATED)==0 && i>0 ){
      Expr *pDestExpr = sqlite3ColumnExpr(pDest, pDestCol);
      Expr *pSrcExpr = sqlite3ColumnExpr(pSrc, pSrcCol);
      assert( pDestExpr==0 || pDestExpr->op==TK_SPAN );
      assert( pDestExpr==0 || !ExprHasProperty(pDestExpr, EP_IntValue) );
      assert( pSrcExpr==0 || pSrcExpr->op==TK_SPAN );
      assert( pSrcExpr==0 || !ExprHasProperty(pSrcExpr, EP_IntValue) );
      if( (pDestExpr==0)!=(pSrcExpr==0)
       || (pDestExpr!=0 && strcmp(pDestExpr->u.zToken,
                                       pSrcExpr->u.zToken)!=0)
      ){
        return 0;    /* Default values must be the same for all columns */
      }
    }
  }
  for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
    if( IsUniqueIndex(pDestIdx) ){
      destHasUniqueIdx = 1;
    }
    for(pSrcIdx=pSrc->pIndex; pSrcIdx; pSrcIdx=pSrcIdx->pNext){
      if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
    }
    if( pSrcIdx==0 ){
      return 0;    /* pDestIdx has no corresponding index in pSrc */
    }
    if( pSrcIdx->tnum==pDestIdx->tnum && pSrc->pSchema==pDest->pSchema
         && sqlite3FaultSim(411)==SQLITE_OK ){
      /* The sqlite3FaultSim() call allows this corruption test to be
      ** bypassed during testing, in order to exercise other corruption tests
      ** further downstream. */
      return 0;   /* Corrupt schema - two indexes on the same btree */
    }
  }
#ifndef SQLITE_OMIT_CHECK
  if( pDest->pCheck
   && (db->mDbFlags & DBFLAG_Vacuum)==0
   && !xferCompatibleCheck(pDest,pSrc)
  ){
    return 0;   /* Tables have different CHECK constraints.  Ticket #2252 */
  }
#endif
#ifndef SQLITE_OMIT_FOREIGN_KEY
  /* Disallow the transfer optimization if the destination table contains
  ** any foreign key constraints.  This is more restrictive than necessary.
  ** But the main beneficiary of the transfer optimization is the VACUUM
  ** command, and the VACUUM command disables foreign key constraints.  So
  ** the extra complication to make this rule less restrictive is probably
  ** not worth the effort.  Ticket [6284df89debdfa61db8073e062908af0c9b6118e]
  */
  assert( IsOrdinaryTable(pDest) );
  if( (db->flags & SQLITE_ForeignKeys)!=0 && pDest->u.tab.pFKey!=0 ){
    return 0;
  }
#endif
  if( (db->flags & SQLITE_CountRows)!=0 ){
    return 0;  /* xfer opt does not play well with PRAGMA count_changes */
  }
#ifndef SQLITE_OMIT_AUTHORIZATION
  if( db->xAuth ){
    int iDb = sqlite3SchemaToIndex(db, pSrc->pSchema);
    if( sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0) ) return 0;
    for(i=0; i<pSrc->nCol; i++){
      Column *pSrcCol = &pSrc->aCol[i];
      if( sqlite3AuthReadCol(pParse, pSrc->zName, pSrcCol->zCnName, iDb) ){
        return 0;
      }
    }
  }
#endif

  /* If we get this far, it means that the xfer optimization is at
  ** least a possibility, though it might only work if the destination
  ** table (tab1) is initially empty.
  */
#ifdef SQLITE_TEST
  sqlite3_xferopt_count++;
#endif
  iDbSrc = sqlite3SchemaToIndex(db, pSrc->pSchema);
  v = sqlite3GetVdbe(pParse);
  sqlite3CodeVerifySchema(pParse, iDbSrc);
  iSrc = pParse->nTab++;
  iDest = pParse->nTab++;
  regAutoinc = autoIncBegin(pParse, iDbDest, pDest);
  regData = sqlite3GetTempReg(pParse);
  sqlite3VdbeAddOp2(v, OP_Null, 0, regData);
  regRowid = sqlite3GetTempReg(pParse);
  sqlite3OpenTable(pParse, iDest, iDbDest, pDest, OP_OpenWrite);
  assert( HasRowid(pDest) || destHasUniqueIdx );
  if( (db->mDbFlags & DBFLAG_Vacuum)==0 && (
      (pDest->iPKey<0 && pDest->pIndex!=0)          /* (1) */
   || destHasUniqueIdx                              /* (2) */
   || (onError!=OE_Abort && onError!=OE_Rollback)   /* (3) */
  )){
    /* In some circumstances, we are able to run the xfer optimization
    ** only if the destination table is initially empty. Unless the
    ** DBFLAG_Vacuum flag is set, this block generates code to make
    ** that determination. If DBFLAG_Vacuum is set, then the destination
    ** table is always empty.
    **
    ** Conditions under which the destination must be empty:
    **
    ** (1) There is no INTEGER PRIMARY KEY but there are indices.
    **     (If the destination is not initially empty, the rowid fields
    **     of index entries might need to change.)
    **
    ** (2) The destination has a unique index.  (The xfer optimization
    **     is unable to test uniqueness.)
    **
    ** (3) onError is something other than OE_Abort and OE_Rollback.
    */
    addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iDest, 0); VdbeCoverage(v);
    emptyDestTest = sqlite3VdbeAddOp0(v, OP_Goto);
    sqlite3VdbeJumpHere(v, addr1);
  }
  if( HasRowid(pSrc) ){
    u8 insFlags;
    sqlite3OpenTable(pParse, iSrc, iDbSrc, pSrc, OP_OpenRead);
    emptySrcTest = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0); VdbeCoverage(v);
    if( pDest->iPKey>=0 ){
      addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
      if( (db->mDbFlags & DBFLAG_Vacuum)==0 ){
        sqlite3VdbeVerifyAbortable(v, onError);
        addr2 = sqlite3VdbeAddOp3(v, OP_NotExists, iDest, 0, regRowid);
        VdbeCoverage(v);
        sqlite3RowidConstraint(pParse, onError, pDest);
        sqlite3VdbeJumpHere(v, addr2);
      }
      autoIncStep(pParse, regAutoinc, regRowid);
    }else if( pDest->pIndex==0 && !(db->mDbFlags & DBFLAG_VacuumInto) ){
      addr1 = sqlite3VdbeAddOp2(v, OP_NewRowid, iDest, regRowid);
    }else{
      addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
      assert( (pDest->tabFlags & TF_Autoincrement)==0 );
    }

    if( db->mDbFlags & DBFLAG_Vacuum ){
      sqlite3VdbeAddOp1(v, OP_SeekEnd, iDest);
      insFlags = OPFLAG_APPEND|OPFLAG_USESEEKRESULT|OPFLAG_PREFORMAT;
    }else{
      insFlags = OPFLAG_NCHANGE|OPFLAG_LASTROWID|OPFLAG_APPEND|OPFLAG_PREFORMAT;
    }
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
    if( (db->mDbFlags & DBFLAG_Vacuum)==0 ){
      sqlite3VdbeAddOp3(v, OP_RowData, iSrc, regData, 1);
      insFlags &= ~OPFLAG_PREFORMAT;
    }else
#endif
    {
      sqlite3VdbeAddOp3(v, OP_RowCell, iDest, iSrc, regRowid);
    }
    sqlite3VdbeAddOp3(v, OP_Insert, iDest, regData, regRowid);
    if( (db->mDbFlags & DBFLAG_Vacuum)==0 ){
      sqlite3VdbeChangeP4(v, -1, (char*)pDest, P4_TABLE);
    }
    sqlite3VdbeChangeP5(v, insFlags);

    sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1); VdbeCoverage(v);
    sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
    sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
  }else{
    sqlite3TableLock(pParse, iDbDest, pDest->tnum, 1, pDest->zName);
    sqlite3TableLock(pParse, iDbSrc, pSrc->tnum, 0, pSrc->zName);
  }
  for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
    u8 idxInsFlags = 0;
    for(pSrcIdx=pSrc->pIndex; ALWAYS(pSrcIdx); pSrcIdx=pSrcIdx->pNext){
      if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
    }
    assert( pSrcIdx );
    sqlite3VdbeAddOp3(v, OP_OpenRead, iSrc, pSrcIdx->tnum, iDbSrc);
    sqlite3VdbeSetP4KeyInfo(pParse, pSrcIdx);
    VdbeComment((v, "%s", pSrcIdx->zName));
    sqlite3VdbeAddOp3(v, OP_OpenWrite, iDest, pDestIdx->tnum, iDbDest);
    sqlite3VdbeSetP4KeyInfo(pParse, pDestIdx);
    sqlite3VdbeChangeP5(v, OPFLAG_BULKCSR);
    VdbeComment((v, "%s", pDestIdx->zName));
    addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0); VdbeCoverage(v);
    if( db->mDbFlags & DBFLAG_Vacuum ){
      /* This INSERT command is part of a VACUUM operation, which guarantees
      ** that the destination table is empty. If all indexed columns use
      ** collation sequence BINARY, then it can also be assumed that the
      ** index will be populated by inserting keys in strictly sorted
      ** order. In this case, instead of seeking within the b-tree as part
      ** of every OP_IdxInsert opcode, an OP_SeekEnd is added before the
      ** OP_IdxInsert to seek to the point within the b-tree where each key
      ** should be inserted. This is faster.
      **
      ** If any of the indexed columns use a collation sequence other than
      ** BINARY, this optimization is disabled. This is because the user
      ** might change the definition of a collation sequence and then run
      ** a VACUUM command. In that case keys may not be written in strictly
      ** sorted order.  */
      for(i=0; i<pSrcIdx->nColumn; i++){
        const char *zColl = pSrcIdx->azColl[i];
        if( sqlite3_stricmp(sqlite3StrBINARY, zColl) ) break;
      }
      if( i==pSrcIdx->nColumn ){
        idxInsFlags = OPFLAG_USESEEKRESULT|OPFLAG_PREFORMAT;
        sqlite3VdbeAddOp1(v, OP_SeekEnd, iDest);
        sqlite3VdbeAddOp2(v, OP_RowCell, iDest, iSrc);
      }
    }else if( !HasRowid(pSrc) && pDestIdx->idxType==SQLITE_IDXTYPE_PRIMARYKEY ){
      idxInsFlags |= OPFLAG_NCHANGE;
    }
    if( idxInsFlags!=(OPFLAG_USESEEKRESULT|OPFLAG_PREFORMAT) ){
      sqlite3VdbeAddOp3(v, OP_RowData, iSrc, regData, 1);
      if( (db->mDbFlags & DBFLAG_Vacuum)==0
       && !HasRowid(pDest)
       && IsPrimaryKeyIndex(pDestIdx)
      ){
        codeWithoutRowidPreupdate(pParse, pDest, iDest, regData);
      }
    }
    sqlite3VdbeAddOp2(v, OP_IdxInsert, iDest, regData);
    sqlite3VdbeChangeP5(v, idxInsFlags|OPFLAG_APPEND);
    sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1+1); VdbeCoverage(v);
    sqlite3VdbeJumpHere(v, addr1);
    sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
    sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
  }
  if( emptySrcTest ) sqlite3VdbeJumpHere(v, emptySrcTest);
  sqlite3ReleaseTempReg(pParse, regRowid);
  sqlite3ReleaseTempReg(pParse, regData);
  if( emptyDestTest ){
    sqlite3AutoincrementEnd(pParse);
    sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_OK, 0);
    sqlite3VdbeJumpHere(v, emptyDestTest);
    sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
    return 0;
  }else{
    return 1;
  }
}
#endif /* SQLITE_OMIT_XFER_OPT */