sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, regRowid);
    }else{
      Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable);
      int j, k, regKey;
      regKey = sqlite3GetTempRange(pParse, pPk->nKeyCol);
      for(j=0; j<pPk->nKeyCol; j++){
        k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]);
        assert( k>=0 && k<pTab->nCol );
        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, regKey+j);
        VdbeComment((v, "%s", pTab->aCol[pPk->aiColumn[j]].zName));
      }
      sqlite3VdbeAddOp3(v, OP_MakeRecord, regKey, pPk->nKeyCol, regRowid);
      sqlite3ReleaseTempRange(pParse, regKey, pPk->nKeyCol);
    }
#endif

      callStatGet(v, regStat4, STAT_GET_NDLT, regDLt);
      sqlite3VdbeAddOp4Int(v, seekOp, iTabCur, addrNext, regSampleRowid, 0);
      /* We know that the regSampleRowid row exists because it was read by
      ** the previous loop.  Thus the not-found jump of seekOp will never
      ** be taken */
      VdbeCoverageNeverTaken(v);
#ifdef SQLITE_ENABLE_STAT3
      sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iTabCur, 0, regSample);

#else
      for(i=0; i<nCol; i++){

        sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iTabCur, i, regCol+i);
      }
      sqlite3VdbeAddOp3(v, OP_MakeRecord, regCol, nCol, regSample);
#endif
      sqlite3VdbeAddOp3(v, OP_MakeRecord, regTabname, 6, regTemp);
      sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur+1, regNewRowid);
      sqlite3VdbeAddOp3(v, OP_Insert, iStatCur+1, regTemp, regNewRowid);
      sqlite3VdbeAddOp2(v, OP_Goto, 1, addrNext); /* P1==1 for end-of-loop */

** Reclaim the memory used by an index
*/
static void freeIndex(sqlite3 *db, Index *p){
#ifndef SQLITE_OMIT_ANALYZE
  sqlite3DeleteIndexSamples(db, p);
#endif
  sqlite3ExprDelete(db, p->pPartIdxWhere);
  sqlite3ExprListDelete(db, p->aColExpr);
  sqlite3DbFree(db, p->zColAff);
  if( p->isResized ) sqlite3DbFree(db, p->azColl);
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  sqlite3_free(p->aiRowEst);
#endif
  sqlite3DbFree(db, p);
}

    pTab->aCol[iCol].colFlags |= COLFLAG_PRIMKEY;
    zType = pTab->aCol[iCol].zType;
    nTerm = 1;
  }else{
    nTerm = pList->nExpr;
    for(i=0; i<nTerm; i++){
      Expr *pCExpr = sqlite3ExprSkipCollate(pList->a[i].pExpr);
      assert( pCExpr!=0 );
      if( pCExpr->op==TK_ID ){
        const char *zCName = pCExpr->u.zToken;
        for(iCol=0; iCol<pTab->nCol; iCol++){
          if( sqlite3StrICmp(zCName, pTab->aCol[iCol].zName)==0 ){
            pTab->aCol[iCol].colFlags |= COLFLAG_PRIMKEY;
            zType = pTab->aCol[iCol].zType;
            break;
          }

  DbFixer sFix;        /* For assigning database names to pTable */
  int sortOrderMask;   /* 1 to honor DESC in index.  0 to ignore. */
  sqlite3 *db = pParse->db;
  Db *pDb;             /* The specific table containing the indexed database */
  int iDb;             /* Index of the database that is being written */
  Token *pName = 0;    /* Unqualified name of the index to create */
  struct ExprList_item *pListItem; /* For looping over pList */

  int nExtra = 0;                  /* Space allocated for zExtra[] */
  int nExtraCol;                   /* Number of extra columns needed */
  char *zExtra = 0;                /* Extra space after the Index object */
  Index *pPk = 0;      /* PRIMARY KEY index for WITHOUT ROWID tables */

  if( db->mallocFailed || IN_DECLARE_VTAB || pParse->nErr>0 ){
    goto exit_create_index;

  }

  /* Figure out how many bytes of space are required to store explicitly
  ** specified collation sequence names.
  */
  for(i=0; i<pList->nExpr; i++){
    Expr *pExpr = pList->a[i].pExpr;
    assert( pExpr!=0 );
    if( pExpr->op==TK_COLLATE ){
      nExtra += (1 + sqlite3Strlen30(pExpr->u.zToken));
    }
  }

  /* 
  ** Allocate the index structure. 
  */

  */
  if( pDb->pSchema->file_format>=4 ){
    sortOrderMask = -1;   /* Honor DESC */
  }else{
    sortOrderMask = 0;    /* Ignore DESC */
  }

  /* Analyze the list of expressions that form the terms of the index and
  ** report any errors.  In the common case where the expression is exactly
  ** a table column, store that column in aiColumn[].  For general expressions,
  ** populate pIndex->aColExpr and store -2 in aiColumn[].
  **
  ** TODO: Issue a warning if two or more columns of the index are identical.



  ** TODO: Issue a warning if the table primary key is used as part of the
  ** index key.
  */
  for(i=0, pListItem=pList->a; i<pList->nExpr; i++, pListItem++){

    Expr *pCExpr;                  /* The i-th index expression */
    int requestedSortOrder;        /* ASC or DESC on the i-th expression */
    char *zColl;                   /* Collation sequence name */

    sqlite3StringToId(pListItem->pExpr);
    sqlite3ResolveSelfReference(pParse, pTab, NC_IdxExpr, pListItem->pExpr, 0);
    if( pParse->nErr ) goto exit_create_index;
    pCExpr = sqlite3ExprSkipCollate(pListItem->pExpr);
    if( pCExpr->op!=TK_COLUMN ){
      if( pTab==pParse->pNewTable ){
        sqlite3ErrorMsg(pParse, "expressions prohibited in PRIMARY KEY and "
                                "UNIQUE constraints");
        goto exit_create_index;
      }
      if( pIndex->aColExpr==0 ){
        ExprList *pCopy = sqlite3ExprListDup(db, pList, 0);
        pIndex->aColExpr = pCopy;
        if( !db->mallocFailed ){
          assert( pCopy!=0 );
          pListItem = &pCopy->a[i];
        }





      }
      j = -2;
      pIndex->aiColumn[i] = -2;
      pIndex->uniqNotNull = 0;
    }else{
      j = pCExpr->iColumn;
      assert( j<=0x7fff );
      if( j<0 ){
        j = pTab->iPKey;
      }else if( pTab->aCol[j].notNull==0 ){
        pIndex->uniqNotNull = 0;
      }
      pIndex->aiColumn[i] = (i16)j;
    }
    zColl = 0;
    if( pListItem->pExpr->op==TK_COLLATE ){
      int nColl;
      zColl = pListItem->pExpr->u.zToken;
      nColl = sqlite3Strlen30(zColl) + 1;
      assert( nExtra>=nColl );
      memcpy(zExtra, zColl, nColl);
      zColl = zExtra;
      zExtra += nColl;
      nExtra -= nColl;
    }else if( j>=0 ){
      zColl = pTab->aCol[j].zColl;

    }
    if( !zColl ) zColl = "BINARY";
    if( !db->init.busy && !sqlite3LocateCollSeq(pParse, zColl) ){
      goto exit_create_index;
    }
    pIndex->azColl[i] = zColl;
    requestedSortOrder = pListItem->sortOrder & sortOrderMask;
    pIndex->aSortOrder[i] = (u8)requestedSortOrder;

  }

  /* Append the table key to the end of the index.  For WITHOUT ROWID
  ** tables (when pPk!=0) this will be the declared PRIMARY KEY.  For
  ** normal tables (when pPk==0) this will be the rowid.
  */
  if( pPk ){
    for(j=0; j<pPk->nKeyCol; j++){
      int x = pPk->aiColumn[j];
      assert( x>=0 );
      if( hasColumn(pIndex->aiColumn, pIndex->nKeyCol, x) ){
        pIndex->nColumn--; 
      }else{
        pIndex->aiColumn[i] = x;
        pIndex->azColl[i] = pPk->azColl[j];
        pIndex->aSortOrder[i] = pPk->aSortOrder[j];
        i++;

      assert( pIdx->idxType!=SQLITE_IDXTYPE_APPDEF );
      assert( IsUniqueIndex(pIndex) );

      if( pIdx->nKeyCol!=pIndex->nKeyCol ) continue;
      for(k=0; k<pIdx->nKeyCol; k++){
        const char *z1;
        const char *z2;
        assert( pIdx->aiColumn[k]>=0 );
        if( pIdx->aiColumn[k]!=pIndex->aiColumn[k] ) break;
        z1 = pIdx->azColl[k];
        z2 = pIndex->azColl[k];
        if( z1!=z2 && sqlite3StrICmp(z1, z2) ) break;
      }
      if( k==pIdx->nKeyCol ){
        if( pIdx->onError!=pIndex->onError ){

      }
    }
  }

  /* Link the new Index structure to its table and to the other
  ** in-memory database structures. 
  */
  assert( pParse->nErr==0 );
  if( db->init.busy ){
    Index *p;
    assert( sqlite3SchemaMutexHeld(db, 0, pIndex->pSchema) );
    p = sqlite3HashInsert(&pIndex->pSchema->idxHash, 
                          pIndex->zName, pIndex);
    if( p ){
      assert( p==pIndex );  /* Malloc must have failed */

  ** of a WITHOUT ROWID table.
  **
  ** If pTblName==0 it means this index is generated as an implied PRIMARY KEY
  ** or UNIQUE index in a CREATE TABLE statement.  Since the table
  ** has just been created, it contains no data and the index initialization
  ** step can be skipped.
  */
  else if( HasRowid(pTab) || pTblName!=0 ){
    Vdbe *v;
    char *zStmt;
    int iMem = ++pParse->nMem;

    v = sqlite3GetVdbe(pParse);
    if( v==0 ) goto exit_create_index;

){
  char *zErr;
  int j;
  StrAccum errMsg;
  Table *pTab = pIdx->pTable;

  sqlite3StrAccumInit(&errMsg, pParse->db, 0, 0, 200);
  if( pIdx->aColExpr ){
    sqlite3XPrintf(&errMsg, 0, "index '%q'", pIdx->zName);
  }else{
    for(j=0; j<pIdx->nKeyCol; j++){
      char *zCol;
      assert( pIdx->aiColumn[j]>=0 );
      zCol = pTab->aCol[pIdx->aiColumn[j]].zName;
      if( j ) sqlite3StrAccumAppend(&errMsg, ", ", 2);
      sqlite3XPrintf(&errMsg, 0, "%s.%s", pTab->zName, zCol);


    }
  }
  zErr = sqlite3StrAccumFinish(&errMsg);
  sqlite3HaltConstraint(pParse, 
    IsPrimaryKeyIndex(pIdx) ? SQLITE_CONSTRAINT_PRIMARYKEY 
                            : SQLITE_CONSTRAINT_UNIQUE,
    onError, zErr, P4_DYNAMIC, P5_ConstraintUnique);
}

** This function registered all of the above C functions as SQL
** functions.  This should be the only routine in this file with
** external linkage.
*/
void sqlite3RegisterDateTimeFunctions(void){
  static SQLITE_WSD FuncDef aDateTimeFuncs[] = {
#ifndef SQLITE_OMIT_DATETIME_FUNCS
    DFUNCTION(julianday,        -1, 0, 0, juliandayFunc ),
    DFUNCTION(date,             -1, 0, 0, dateFunc      ),
    DFUNCTION(time,             -1, 0, 0, timeFunc      ),
    DFUNCTION(datetime,         -1, 0, 0, datetimeFunc  ),
    DFUNCTION(strftime,         -1, 0, 0, strftimeFunc  ),
    DFUNCTION(current_time,      0, 0, 0, ctimeFunc     ),
    DFUNCTION(current_timestamp, 0, 0, 0, ctimestampFunc),
    DFUNCTION(current_date,      0, 0, 0, cdateFunc     ),
#else
    STR_FUNCTION(current_time,      0, "%H:%M:%S",          0, currentTimeFunc),
    STR_FUNCTION(current_date,      0, "%Y-%m-%d",          0, currentTimeFunc),
    STR_FUNCTION(current_timestamp, 0, "%Y-%m-%d %H:%M:%S", 0, currentTimeFunc),
#endif
  };
  int i;

    if( db->flags & SQLITE_CountRows ){
      sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);
    }
  
    /* Extract the rowid or primary key for the current row */
    if( pPk ){
      for(i=0; i<nPk; i++){
        assert( pPk->aiColumn[i]>=(-1) );
        sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur,
                                        pPk->aiColumn[i], iPk+i);
      }
      iKey = iPk;
    }else{
      iKey = pParse->nMem + 1;
      iKey = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iTabCur, iKey, 0);

  int prefixOnly,      /* Compute only a unique prefix of the key */
  int *piPartIdxLabel, /* OUT: Jump to this label to skip partial index */
  Index *pPrior,       /* Previously generated index key */
  int regPrior         /* Register holding previous generated key */
){
  Vdbe *v = pParse->pVdbe;
  int j;

  int regBase;
  int nCol;

  if( piPartIdxLabel ){
    if( pIdx->pPartIdxWhere ){
      *piPartIdxLabel = sqlite3VdbeMakeLabel(v);
      pParse->iSelfTab = iDataCur;
      sqlite3ExprCachePush(pParse);
      sqlite3ExprIfFalseDup(pParse, pIdx->pPartIdxWhere, *piPartIdxLabel, 
                            SQLITE_JUMPIFNULL);
    }else{
      *piPartIdxLabel = 0;
    }
  }
  nCol = (prefixOnly && pIdx->uniqNotNull) ? pIdx->nKeyCol : pIdx->nColumn;
  regBase = sqlite3GetTempRange(pParse, nCol);
  if( pPrior && (regBase!=regPrior || pPrior->pPartIdxWhere) ) pPrior = 0;
  for(j=0; j<nCol; j++){
    if( pPrior
     && pPrior->aiColumn[j]==pIdx->aiColumn[j]
     && pPrior->aiColumn[j]>=(-1)
    ){
      /* This column was already computed by the previous index */
      continue;
    }
    sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iDataCur, j, regBase+j);
    /* If the column affinity is REAL but the number is an integer, then it
    ** might be stored in the table as an integer (using a compact
    ** representation) then converted to REAL by an OP_RealAffinity opcode.
    ** But we are getting ready to store this value back into an index, where
    ** it should be converted by to INTEGER again.  So omit the OP_RealAffinity
    ** opcode if it is present */
    sqlite3VdbeDeletePriorOpcode(v, OP_RealAffinity);

  struct yColCache *p;
  for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
    if( p->iReg==iReg ){
      p->tempReg = 0;
    }
  }
}

/* Generate code that will load into register regOut a value that is
** appropriate for the iIdxCol-th column of index pIdx.
*/
void sqlite3ExprCodeLoadIndexColumn(
  Parse *pParse,  /* The parsing context */
  Index *pIdx,    /* The index whose column is to be loaded */
  int iTabCur,    /* Cursor pointing to a table row */
  int iIdxCol,    /* The column of the index to be loaded */
  int regOut      /* Store the index column value in this register */
){
  i16 iTabCol = pIdx->aiColumn[iIdxCol];
  if( iTabCol>=(-1) ){
    sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pIdx->pTable, iTabCur,
                                    iTabCol, regOut);
    return;
  }
  assert( pIdx->aColExpr );
  assert( pIdx->aColExpr->nExpr>iIdxCol );
  pParse->iSelfTab = iTabCur;
  sqlite3ExprCode(pParse, pIdx->aColExpr->a[iIdxCol].pExpr, regOut);
}

/*
** Generate code to extract the value of the iCol-th column of a table.
*/
void sqlite3ExprCodeGetColumnOfTable(
  Vdbe *v,        /* The VDBE under construction */
  Table *pTab,    /* The table containing the value */

      int iTab = pExpr->iTable;
      if( iTab<0 ){
        if( pParse->ckBase>0 ){
          /* Generating CHECK constraints or inserting into partial index */
          inReg = pExpr->iColumn + pParse->ckBase;
          break;
        }else{
          /* Coding an expression that is part of an index where column names
          ** in the index refer to the table to which the index belongs */
          iTab = pParse->iSelfTab;
        }
      }
      inReg = sqlite3ExprCodeGetColumn(pParse, pExpr->pTab,
                               pExpr->iColumn, iTab, target,
                               pExpr->op2);
      break;
    }

    }
    if( pB->op==TK_COLLATE && sqlite3ExprCompare(pA, pB->pLeft, iTab)<2 ){
      return 1;
    }
    return 2;
  }
  if( pA->op!=TK_COLUMN && ALWAYS(pA->op!=TK_AGG_COLUMN) && pA->u.zToken ){
    if( pA->op==TK_FUNCTION ){
      if( sqlite3StrICmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;
    }else if( strcmp(pA->u.zToken,pB->u.zToken)!=0 ){
      return pA->op==TK_COLLATE ? 1 : 2;
    }
  }
  if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 2;
  if( ALWAYS((combinedFlags & EP_TokenOnly)==0) ){
    if( combinedFlags & EP_xIsSelect ) return 2;
    if( sqlite3ExprCompare(pA->pLeft, pB->pLeft, iTab) ) return 2;

    FUNCTION2(ifnull,            2, 0, 0, noopFunc,  SQLITE_FUNC_COALESCE),
    FUNCTION2(unlikely,          1, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),
    FUNCTION2(likelihood,        2, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),
    FUNCTION2(likely,            1, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),
    VFUNCTION(random,            0, 0, 0, randomFunc       ),
    VFUNCTION(randomblob,        1, 0, 0, randomBlob       ),
    FUNCTION(nullif,             2, 0, 1, nullifFunc       ),
    DFUNCTION(sqlite_version,    0, 0, 0, versionFunc      ),
    DFUNCTION(sqlite_source_id,  0, 0, 0, sourceidFunc     ),
    FUNCTION(sqlite_log,         2, 0, 0, errlogFunc       ),
#if SQLITE_USER_AUTHENTICATION
    FUNCTION(sqlite_crypt,       2, 0, 0, sqlite3CryptFunc ),
#endif
#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
    DFUNCTION(sqlite_compileoption_used,1, 0, 0, compileoptionusedFunc  ),
    DFUNCTION(sqlite_compileoption_get, 1, 0, 0, compileoptiongetFunc  ),
#endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
    FUNCTION(quote,              1, 0, 0, quoteFunc        ),
    VFUNCTION(last_insert_rowid, 0, 0, 0, last_insert_rowid),
    VFUNCTION(changes,           0, 0, 0, changes          ),
    VFUNCTION(total_changes,     0, 0, 0, total_changes    ),
    FUNCTION(replace,            3, 0, 0, replaceFunc      ),
    FUNCTION(zeroblob,           1, 0, 0, zeroblobFunc     ),
  #ifdef SQLITE_SOUNDEX
    FUNCTION(soundex,            1, 0, 0, soundexFunc      ),
  #endif
  #ifndef SQLITE_OMIT_LOAD_EXTENSION
    VFUNCTION(load_extension,    1, 0, 0, loadExt          ),
    VFUNCTION(load_extension,    2, 0, 0, loadExt          ),
  #endif
    AGGREGATE(sum,               1, 0, 0, sumStep,         sumFinalize    ),
    AGGREGATE(total,             1, 0, 0, sumStep,         totalFinalize    ),
    AGGREGATE(avg,               1, 0, 0, sumStep,         avgFinalize    ),
    AGGREGATE2(count,            0, 0, 0, countStep,       countFinalize,
               SQLITE_FUNC_COUNT  ),
    AGGREGATE(count,             1, 0, 0, countStep,       countFinalize  ),

    pIdx->zColAff = (char *)sqlite3DbMallocRaw(0, pIdx->nColumn+1);
    if( !pIdx->zColAff ){
      db->mallocFailed = 1;
      return 0;
    }
    for(n=0; n<pIdx->nColumn; n++){
      i16 x = pIdx->aiColumn[n];
      if( x>=0 ){
        pIdx->zColAff[n] = pTab->aCol[x].affinity;
      }else if( x==(-1) ){
        pIdx->zColAff[n] = SQLITE_AFF_INTEGER;
      }else{
        char aff;
        assert( x==(-2) );
        assert( pIdx->aColExpr!=0 );
        aff = sqlite3ExprAffinity(pIdx->aColExpr->a[n].pExpr);
        if( aff==0 ) aff = SQLITE_AFF_BLOB;
        pIdx->zColAff[n] = aff;
      }
    }
    pIdx->zColAff[n] = 0;
  }
 
  return pIdx->zColAff;
}

    /* 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 = sqlite3GetTempRange(pParse, pIdx->nColumn);
    for(i=0; i<pIdx->nColumn; i++){
      int iField = pIdx->aiColumn[i];
      int x;
      if( iField==(-2) ){
        pParse->ckBase = regNewData+1;
        sqlite3ExprCode(pParse, pIdx->aColExpr->a[i].pExpr, regIdx+i);
        pParse->ckBase = 0;
        VdbeComment((v, "%s column %d", pIdx->zName, i));
      }else{
        if( iField==(-1) || iField==pTab->iPKey ){
          if( regRowid==regIdx+i ) continue; /* ROWID already in regIdx+i */
          x = regNewData;
          regRowid =  pIdx->pPartIdxWhere ? -1 : regIdx+i;
        }else{
          x = iField + regNewData + 1;
        }
        sqlite3VdbeAddOp2(v, OP_SCopy, x, regIdx+i);
        VdbeComment((v, "%s", iField<0 ? "rowid" : pTab->aCol[iField].zName));
      }
    }
    sqlite3VdbeAddOp3(v, OP_MakeRecord, regIdx, pIdx->nColumn, aRegIdx[ix]);
    VdbeComment((v, "for %s", pIdx->zName));
    sqlite3ExprCacheAffinityChange(pParse, regIdx, pIdx->nColumn);

    /* In an UPDATE operation, if this index is the PRIMARY KEY index 
    ** of a WITHOUT ROWID table and there has been no change the

  }
  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]==(-2) ){
      assert( pSrc->aColExpr!=0 && pDest->aColExpr!=0 );
      if( sqlite3ExprCompare(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( !xferCompatibleCollation(pSrc->azColl[i],pDest->azColl[i]) ){
      return 0;   /* Different collating sequences */
    }

    }
    ExprSetProperty(p, EP_Resolved);
  }
  return p;
}

/*
** Report an error that an expression is not valid for some set of
** pNC->ncFlags values determined by validMask.
*/
static void notValid(
  Parse *pParse,       /* Leave error message here */
  NameContext *pNC,    /* The name context */
  const char *zMsg,    /* Type of error */
  int validMask        /* Set of contexts for which prohibited */
){
  assert( (validMask&~(NC_IsCheck|NC_PartIdx|NC_IdxExpr))==0 );
  if( (pNC->ncFlags & validMask)!=0 ){
    const char *zIn = "partial index WHERE clauses";



    if( pNC->ncFlags & NC_IdxExpr )      zIn = "index expressions";
#ifndef SQLITE_OMIT_CHECK








    else if( pNC->ncFlags & NC_IsCheck ) zIn = "CHECK constraints";
#endif
    sqlite3ErrorMsg(pParse, "%s prohibited in %s", zMsg, zIn);
  }
}




/*
** Expression p should encode a floating point value between 1.0 and 0.0.
** Return 1024 times this value.  Or return -1 if p is not a floating point
** value between 1.0 and 0.0.
*/
static int exprProbability(Expr *p){

    case TK_DOT: {
      const char *zColumn;
      const char *zTable;
      const char *zDb;
      Expr *pRight;

      /* if( pSrcList==0 ) break; */
      notValid(pParse, pNC, "the \".\" operator", NC_IdxExpr);
      /*notValid(pParse, pNC, "the \".\" operator", NC_PartIdx|NC_IsCheck, 1);*/
      pRight = pExpr->pRight;
      if( pRight->op==TK_ID ){
        zDb = 0;
        zTable = pExpr->pLeft->u.zToken;
        zColumn = pRight->u.zToken;
      }else{
        assert( pRight->op==TK_DOT );

      int auth;                   /* Authorization to use the function */
      int nId;                    /* Number of characters in function name */
      const char *zId;            /* The function name. */
      FuncDef *pDef;              /* Information about the function */
      u8 enc = ENC(pParse->db);   /* The database encoding */

      assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
      notValid(pParse, pNC, "functions", NC_PartIdx);
      zId = pExpr->u.zToken;
      nId = sqlite3Strlen30(zId);
      pDef = sqlite3FindFunction(pParse->db, zId, nId, n, enc, 0);
      if( pDef==0 ){
        pDef = sqlite3FindFunction(pParse->db, zId, nId, -2, enc, 0);
        if( pDef==0 ){
          no_such_func = 1;

                                    pDef->zName);
            pNC->nErr++;
          }
          pExpr->op = TK_NULL;
          return WRC_Prune;
        }
#endif
        if( pDef->funcFlags & (SQLITE_FUNC_CONSTANT|SQLITE_FUNC_SLOCHNG) ){
          /* For the purposes of the EP_ConstFunc flag, date and time
          ** functions and other functions that change slowly are considered
          ** constant because they are constant for the duration of one query */
          ExprSetProperty(pExpr,EP_ConstFunc);
        }
        if( (pDef->funcFlags & SQLITE_FUNC_CONSTANT)==0 ){
          /* Date/time functions that use 'now', and other functions like
          ** sqlite_version() that might change over time cannot be used
          ** in an index. */
          notValid(pParse, pNC, "non-deterministic functions", NC_IdxExpr);
        }
      }
      if( is_agg && (pNC->ncFlags & NC_AllowAgg)==0 ){
        sqlite3ErrorMsg(pParse, "misuse of aggregate function %.*s()", nId,zId);
        pNC->nErr++;
        is_agg = 0;
      }else if( no_such_func && pParse->db->init.busy==0 ){
        sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId);

    case TK_SELECT:
    case TK_EXISTS:  testcase( pExpr->op==TK_EXISTS );
#endif
    case TK_IN: {
      testcase( pExpr->op==TK_IN );
      if( ExprHasProperty(pExpr, EP_xIsSelect) ){
        int nRef = pNC->nRef;
        notValid(pParse, pNC, "subqueries", NC_IsCheck|NC_PartIdx|NC_IdxExpr);

        sqlite3WalkSelect(pWalker, pExpr->x.pSelect);
        assert( pNC->nRef>=nRef );
        if( nRef!=pNC->nRef ){
          ExprSetProperty(pExpr, EP_VarSelect);
        }
      }
      break;
    }
    case TK_VARIABLE: {
      notValid(pParse, pNC, "parameters", NC_IsCheck|NC_PartIdx|NC_IdxExpr);

      break;
    }
  }
  return (pParse->nErr || pParse->db->mallocFailed) ? WRC_Abort : WRC_Continue;
}

/*

** is set to -1 and the Expr.iColumn value is set to the column number.
**
** Any errors cause an error message to be set in pParse.
*/
void sqlite3ResolveSelfReference(
  Parse *pParse,      /* Parsing context */
  Table *pTab,        /* The table being referenced */
  int type,           /* NC_IsCheck or NC_PartIdx or NC_IdxExpr */
  Expr *pExpr,        /* Expression to resolve.  May be NULL. */
  ExprList *pList     /* Expression list to resolve.  May be NUL. */
){
  SrcList sSrc;                   /* Fake SrcList for pParse->pNewTable */
  NameContext sNC;                /* Name context for pParse->pNewTable */

  assert( type==NC_IsCheck || type==NC_PartIdx || type==NC_IdxExpr );
  memset(&sNC, 0, sizeof(sNC));
  memset(&sSrc, 0, sizeof(sSrc));
  sSrc.nSrc = 1;
  sSrc.a[0].zName = pTab->zName;
  sSrc.a[0].pTab = pTab;
  sSrc.a[0].iCursor = -1;
  sNC.pParse = pParse;
  sNC.pSrcList = &sSrc;
  sNC.ncFlags = type;
  if( sqlite3ResolveExprNames(&sNC, pExpr) ) return;
  if( pList ) sqlite3ResolveExprListNames(&sNC, pList);
}

    }
  }
  if( nSql ){
    if( !_all_whitespace(zSql) ){
      fprintf(stderr, "Error: incomplete SQL: %s\n", zSql);
      errCnt++;
    }

  }
  free(zSql);
  free(zLine);
  return errCnt>0;
}

/*
** Return a pathname which is the user's home directory.  A
** 0 return indicates an error of some kind.

};

/*
** Possible values for FuncDef.flags.  Note that the _LENGTH and _TYPEOF
** values must correspond to OPFLAG_LENGTHARG and OPFLAG_TYPEOFARG.  There
** are assert() statements in the code to verify this.
*/
#define SQLITE_FUNC_ENCMASK  0x0003 /* SQLITE_UTF8, SQLITE_UTF16BE or UTF16LE */
#define SQLITE_FUNC_LIKE     0x0004 /* Candidate for the LIKE optimization */
#define SQLITE_FUNC_CASE     0x0008 /* Case-sensitive LIKE-type function */
#define SQLITE_FUNC_EPHEM    0x0010 /* Ephemeral.  Delete with VDBE */
#define SQLITE_FUNC_NEEDCOLL 0x0020 /* sqlite3GetFuncCollSeq() might be called*/
#define SQLITE_FUNC_LENGTH   0x0040 /* Built-in length() function */
#define SQLITE_FUNC_TYPEOF   0x0080 /* Built-in typeof() function */
#define SQLITE_FUNC_COUNT    0x0100 /* Built-in count(*) aggregate */
#define SQLITE_FUNC_COALESCE 0x0200 /* Built-in coalesce() or ifnull() */
#define SQLITE_FUNC_UNLIKELY 0x0400 /* Built-in unlikely() function */
#define SQLITE_FUNC_CONSTANT 0x0800 /* Constant inputs give a constant output */
#define SQLITE_FUNC_MINMAX   0x1000 /* True for min() and max() aggregates */
#define SQLITE_FUNC_SLOCHNG  0x2000 /* "Slow Change". Value constant during a
                                    ** single query - might change over time */

/*
** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are
** used to create the initializers for the FuncDef structures.
**
**   FUNCTION(zName, nArg, iArg, bNC, xFunc)
**     Used to create a scalar function definition of a function zName 
**     implemented by C function xFunc that accepts nArg arguments. The
**     value passed as iArg is cast to a (void*) and made available
**     as the user-data (sqlite3_user_data()) for the function. If 
**     argument bNC is true, then the SQLITE_FUNC_NEEDCOLL flag is set.
**
**   VFUNCTION(zName, nArg, iArg, bNC, xFunc)
**     Like FUNCTION except it omits the SQLITE_FUNC_CONSTANT flag.
**
**   DFUNCTION(zName, nArg, iArg, bNC, xFunc)
**     Like FUNCTION except it omits the SQLITE_FUNC_CONSTANT flag and
**     adds the SQLITE_FUNC_SLOCHNG flag.  Used for date & time functions
**     and functions like sqlite_version() that can change, but not during
**     a single query.
**
**   AGGREGATE(zName, nArg, iArg, bNC, xStep, xFinal)
**     Used to create an aggregate function definition implemented by
**     the C functions xStep and xFinal. The first four parameters
**     are interpreted in the same way as the first 4 parameters to
**     FUNCTION().
**

*/
#define FUNCTION(zName, nArg, iArg, bNC, xFunc) \
  {nArg, SQLITE_FUNC_CONSTANT|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
#define VFUNCTION(zName, nArg, iArg, bNC, xFunc) \
  {nArg, SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
#define DFUNCTION(zName, nArg, iArg, bNC, xFunc) \
  {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
#define FUNCTION2(zName, nArg, iArg, bNC, xFunc, extraFlags) \
  {nArg,SQLITE_FUNC_CONSTANT|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL)|extraFlags,\
   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
#define STR_FUNCTION(zName, nArg, pArg, bNC, xFunc) \
  {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
   pArg, 0, xFunc, 0, 0, #zName, 0, 0}
#define LIKEFUNC(zName, nArg, arg, flags) \
  {nArg, SQLITE_FUNC_CONSTANT|SQLITE_UTF8|flags, \
   (void *)arg, 0, likeFunc, 0, 0, #zName, 0, 0}
#define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \
  {nArg, SQLITE_UTF8|(nc*SQLITE_FUNC_NEEDCOLL), \
   SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal,#zName,0,0}

  Table *pTable;           /* The SQL table being indexed */
  char *zColAff;           /* String defining the affinity of each column */
  Index *pNext;            /* The next index associated with the same table */
  Schema *pSchema;         /* Schema containing this index */
  u8 *aSortOrder;          /* for each column: True==DESC, False==ASC */
  char **azColl;           /* Array of collation sequence names for index */
  Expr *pPartIdxWhere;     /* WHERE clause for partial indices */
  ExprList *aColExpr;      /* Column expressions */
  int tnum;                /* DB Page containing root of this index */
  LogEst szIdxRow;         /* Estimated average row size in bytes */
  u16 nKeyCol;             /* Number of columns forming the key */
  u16 nColumn;             /* Number of columns stored in the index */
  u8 onError;              /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
  unsigned idxType:2;      /* 1==UNIQUE, 2==PRIMARY KEY, 0==CREATE INDEX */
  unsigned bUnordered:1;   /* Use this index for == or IN queries only */

#define EP_Skip      0x001000 /* COLLATE, AS, or UNLIKELY */
#define EP_Reduced   0x002000 /* Expr struct EXPR_REDUCEDSIZE bytes only */
#define EP_TokenOnly 0x004000 /* Expr struct EXPR_TOKENONLYSIZE bytes only */
#define EP_Static    0x008000 /* Held in memory not obtained from malloc() */
#define EP_MemToken  0x010000 /* Need to sqlite3DbFree() Expr.zToken */
#define EP_NoReduce  0x020000 /* Cannot EXPRDUP_REDUCE this Expr */
#define EP_Unlikely  0x040000 /* unlikely() or likelihood() function */
#define EP_ConstFunc 0x080000 /* A SQLITE_FUNC_CONSTANT or _SLOCHNG function */
#define EP_CanBeNull 0x100000 /* Can be null despite NOT NULL constraint */
#define EP_Subquery  0x200000 /* Tree contains a TK_SELECT operator */

/*
** Combinations of two or more EP_* flags
*/
#define EP_Propagate (EP_Collate|EP_Subquery) /* Propagate these bits up tree */

** 
*/
#define NC_AllowAgg  0x0001  /* Aggregate functions are allowed here */
#define NC_HasAgg    0x0002  /* One or more aggregate functions seen */
#define NC_IsCheck   0x0004  /* True if resolving names in a CHECK constraint */
#define NC_InAggFunc 0x0008  /* True if analyzing arguments to an agg func */
#define NC_PartIdx   0x0010  /* True if resolving a partial index WHERE */
#define NC_IdxExpr   0x0020  /* True if resolving columns of CREATE INDEX */
#define NC_MinMaxAgg 0x1000  /* min/max aggregates seen.  See note above */

/*
** An instance of the following structure contains all information
** needed to generate code for a single SELECT statement.
**
** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.

  int nTab;            /* Number of previously allocated VDBE cursors */
  int nMem;            /* Number of memory cells used so far */
  int nSet;            /* Number of sets used so far */
  int nOnce;           /* Number of OP_Once instructions so far */
  int nOpAlloc;        /* Number of slots allocated for Vdbe.aOp[] */
  int iFixedOp;        /* Never back out opcodes iFixedOp-1 or earlier */
  int ckBase;          /* Base register of data during check constraints */
  int iSelfTab;        /* Table of an index whose exprs are being coded */
  int iCacheLevel;     /* ColCache valid when aColCache[].iLevel<=iCacheLevel */
  int iCacheCnt;       /* Counter used to generate aColCache[].lru values */
  int nLabel;          /* Number of labels used */
  int *aLabel;         /* Space to hold the labels */
  struct yColCache {
    int iTable;           /* Table cursor number */
    i16 iColumn;          /* Table column number */

u64 sqlite3WhereOutputRowCount(WhereInfo*);
int sqlite3WhereIsDistinct(WhereInfo*);
int sqlite3WhereIsOrdered(WhereInfo*);
int sqlite3WhereIsSorted(WhereInfo*);
int sqlite3WhereContinueLabel(WhereInfo*);
int sqlite3WhereBreakLabel(WhereInfo*);
int sqlite3WhereOkOnePass(WhereInfo*, int*);
void sqlite3ExprCodeLoadIndexColumn(Parse*, Index*, int, int, int);
int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, u8);
void sqlite3ExprCodeGetColumnOfTable(Vdbe*, Table*, int, int, int);
void sqlite3ExprCodeMove(Parse*, int, int, int);
void sqlite3ExprCacheStore(Parse*, int, int, int);
void sqlite3ExprCachePush(Parse*);
void sqlite3ExprCachePop(Parse*);
void sqlite3ExprCacheRemove(Parse*, int, int);

  */
  pTabList->a[0].colUsed = 0;

  hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngKey);

  /* There is one entry in the aRegIdx[] array for each index on the table
  ** being updated.  Fill in aRegIdx[] with a register number that will hold
  ** the key for accessing each index.
  **
  ** FIXME:  Be smarter about omitting indexes that use expressions.
  */
  for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
    int reg;
    if( chngKey || hasFK || pIdx->pPartIdxWhere || pIdx==pPk ){
      reg = ++pParse->nMem;
    }else{
      reg = 0;
      for(i=0; i<pIdx->nKeyCol; i++){
        i16 iIdxCol = pIdx->aiColumn[i];
        if( iIdxCol<0 || aXRef[iIdxCol]>=0 ){
          reg = ++pParse->nMem;
          break;
        }
      }
    }
    if( reg==0 ) aToOpen[j+1] = 0;
    aRegIdx[j] = reg;

    addrOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEph, nPk);
    sqlite3VdbeSetP4KeyInfo(pParse, pPk);
    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, 
                               WHERE_ONEPASS_DESIRED, iIdxCur);
    if( pWInfo==0 ) goto update_cleanup;
    okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
    for(i=0; i<nPk; i++){
      assert( pPk->aiColumn[i]>=(-1) );
      sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, pPk->aiColumn[i],
                                      iPk+i);
    }
    if( okOnePass ){
      sqlite3VdbeChangeToNoop(v, addrOpen);
      nKey = nPk;
      regKey = iPk;

          }
        }
      }
#endif
      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
        int j;
        for(j=0; j<pIdx->nKeyCol; j++){
          /* FIXME: Be smarter about indexes that use expressions */
          if( pIdx->aiColumn[j]==iCol || pIdx->aiColumn[j]==(-2) ){
            zFault = "indexed";
          }
        }
      }
      if( zFault ){
        sqlite3DbFree(db, zErr);
        zErr = sqlite3MPrintf(db, "cannot open %s column for writing", zFault);

  WhereClause *pWC;    /* Shorthand for pScan->pWC */
  WhereTerm *pTerm;    /* The term being tested */
  int k = pScan->k;    /* Where to start scanning */

  while( pScan->iEquiv<=pScan->nEquiv ){
    iCur = pScan->aiCur[pScan->iEquiv-1];
    iColumn = pScan->aiColumn[pScan->iEquiv-1];
    assert( iColumn!=(-2) || pScan->pIdxExpr!=0 );
    while( (pWC = pScan->pWC)!=0 ){
      for(pTerm=pWC->a+k; k<pWC->nTerm; k++, pTerm++){
        if( pTerm->leftCursor==iCur
         && pTerm->u.leftColumn==iColumn
         && (iColumn!=(-2)
               || sqlite3ExprCompare(pTerm->pExpr->pLeft,pScan->pIdxExpr,iCur)==0)
         && (pScan->iEquiv<=1 || !ExprHasProperty(pTerm->pExpr, EP_FromJoin))
        ){
          if( (pTerm->eOperator & WO_EQUIV)!=0
           && pScan->nEquiv<ArraySize(pScan->aiCur)
           && (pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight))->op==TK_COLUMN
          ){
            int j;


            for(j=0; j<pScan->nEquiv; j++){
              if( pScan->aiCur[j]==pX->iTable
               && pScan->aiColumn[j]==pX->iColumn ){
                  break;
              }
            }
            if( j==pScan->nEquiv ){

  Index *pIdx             /* Must be compatible with this index */
){
  int j;

  /* memset(pScan, 0, sizeof(*pScan)); */
  pScan->pOrigWC = pWC;
  pScan->pWC = pWC;
  pScan->pIdxExpr = 0;
  if( pIdx ){
    j = iColumn;
    iColumn = pIdx->aiColumn[j];
    if( iColumn==(-2) ) pScan->pIdxExpr = pIdx->aColExpr->a[j].pExpr;
  }
  if( pIdx && iColumn>=0 ){
    pScan->idxaff = pIdx->pTable->aCol[iColumn].affinity;
    pScan->zCollName = pIdx->azColl[j];
  }else{
    pScan->idxaff = 0;
    pScan->zCollName = 0;
  }
  pScan->opMask = opMask;
  pScan->k = 0;
  pScan->aiCur[0] = iCur;
  pScan->aiColumn[0] = iColumn;
  pScan->nEquiv = 1;
  pScan->iEquiv = 1;
  return whereScanNext(pScan);
}

/*
** Search for a term in the WHERE clause that is of the form "X <op> <expr>"
** where X is a reference to the iColumn of table iCur and <op> is one of
** the WO_xx operator codes specified by the op parameter.
** Return a pointer to the term.  Return 0 if not found.
**
** If pIdx!=0 then search for terms matching the iColumn-th column of pIdx
** rather than the iColumn-th column of table iCur.
**
** The term returned might by Y=<expr> if there is another constraint in
** the WHERE clause that specifies that X=Y.  Any such constraints will be
** identified by the WO_EQUIV bit in the pTerm->eOperator field.  The
** aiCur[]/iaColumn[] arrays hold X and all its equivalents. There are 11
** slots in aiCur[]/aiColumn[] so that means we can look for X plus up to 10
** other equivalent values.  Hence a search for X will return <expr> if X=A1

        return i;
      }
    }
  }

  return -1;
}

/*
** Return TRUE if the iCol-th column of index pIdx is NOT NULL
*/
static int indexColumnNotNull(Index *pIdx, int iCol){
  int j;
  assert( pIdx!=0 );
  assert( iCol>=0 && iCol<pIdx->nColumn );
  j = pIdx->aiColumn[iCol];
  if( j>=0 ){
    return pIdx->pTable->aCol[j].notNull;
  }else if( j==(-1) ){
    return 1;
  }else{
    assert( j==(-2) );
    return 0;  /* Assume an indexed expression can always yield a NULL */

  }
}

/*
** Return true if the DISTINCT expression-list passed as the third argument
** is redundant.
**
** A DISTINCT list is redundant if any subset of the columns in the
** DISTINCT list are collectively unique and individually non-null.

  **
  **   3. All of those index columns for which the WHERE clause does not
  **      contain a "col=X" term are subject to a NOT NULL constraint.
  */
  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
    if( !IsUniqueIndex(pIdx) ) continue;
    for(i=0; i<pIdx->nKeyCol; i++){

      if( 0==sqlite3WhereFindTerm(pWC, iBase, i, ~(Bitmask)0, WO_EQ, pIdx) ){
        if( findIndexCol(pParse, pDistinct, iBase, pIdx, i)<0 ) break;

        if( indexColumnNotNull(pIdx, i)==0 ) break;

      }
    }
    if( i==pIdx->nKeyCol ){
      /* This index implies that the DISTINCT qualifier is redundant. */
      return 1;
    }
  }

    assert( IsPowerOfTwo(pTerm->eOperator & ~WO_EQUIV) );
    testcase( pTerm->eOperator & WO_IN );
    testcase( pTerm->eOperator & WO_ISNULL );
    testcase( pTerm->eOperator & WO_IS );
    testcase( pTerm->eOperator & WO_ALL );
    if( (pTerm->eOperator & ~(WO_ISNULL|WO_EQUIV|WO_IS))==0 ) continue;
    if( pTerm->wtFlags & TERM_VNULL ) continue;
    assert( pTerm->u.leftColumn>=(-1) );
    nTerm++;
  }

  /* If the ORDER BY clause contains only columns in the current 
  ** virtual table then allocate space for the aOrderBy part of
  ** the sqlite3_index_info structure.
  */

    assert( IsPowerOfTwo(pTerm->eOperator & ~WO_EQUIV) );
    testcase( pTerm->eOperator & WO_IN );
    testcase( pTerm->eOperator & WO_IS );
    testcase( pTerm->eOperator & WO_ISNULL );
    testcase( pTerm->eOperator & WO_ALL );
    if( (pTerm->eOperator & ~(WO_ISNULL|WO_EQUIV|WO_IS))==0 ) continue;
    if( pTerm->wtFlags & TERM_VNULL ) continue;
    assert( pTerm->u.leftColumn>=(-1) );
    pIdxCons[j].iColumn = pTerm->u.leftColumn;
    pIdxCons[j].iTermOffset = i;
    op = (u8)pTerm->eOperator & WO_ALL;
    if( op==WO_IN ) op = WO_EQ;
    pIdxCons[j].op = op;
    /* The direct assignment in the previous line is possible only because
    ** the WO_ and SQLITE_INDEX_CONSTRAINT_ codes are identical.  The

  WhereScan scan;                 /* Iterator for WHERE terms */
  Bitmask saved_prereq;           /* Original value of pNew->prereq */
  u16 saved_nLTerm;               /* Original value of pNew->nLTerm */
  u16 saved_nEq;                  /* Original value of pNew->u.btree.nEq */
  u16 saved_nSkip;                /* Original value of pNew->nSkip */
  u32 saved_wsFlags;              /* Original value of pNew->wsFlags */
  LogEst saved_nOut;              /* Original value of pNew->nOut */

  int rc = SQLITE_OK;             /* Return code */
  LogEst rSize;                   /* Number of rows in the table */
  LogEst rLogSize;                /* Logarithm of table size */
  WhereTerm *pTop = 0, *pBtm = 0; /* Top and bottom range constraints */

  pNew = pBuilder->pNew;
  if( db->mallocFailed ) return SQLITE_NOMEM;

  assert( (pNew->wsFlags & WHERE_VIRTUALTABLE)==0 );
  assert( (pNew->wsFlags & WHERE_TOP_LIMIT)==0 );
  if( pNew->wsFlags & WHERE_BTM_LIMIT ){
    opMask = WO_LT|WO_LE;
  }else if( /*pProbe->tnum<=0 ||*/ (pSrc->fg.jointype & JT_LEFT)!=0 ){
    opMask = WO_EQ|WO_IN|WO_GT|WO_GE|WO_LT|WO_LE;
  }else{
    opMask = WO_EQ|WO_IN|WO_GT|WO_GE|WO_LT|WO_LE|WO_ISNULL|WO_IS;
  }
  if( pProbe->bUnordered ) opMask &= ~(WO_GT|WO_GE|WO_LT|WO_LE);

  assert( pNew->u.btree.nEq<pProbe->nColumn );




  saved_nEq = pNew->u.btree.nEq;
  saved_nSkip = pNew->nSkip;
  saved_nLTerm = pNew->nLTerm;
  saved_wsFlags = pNew->wsFlags;
  saved_prereq = pNew->prereq;
  saved_nOut = pNew->nOut;
  pTerm = whereScanInit(&scan, pBuilder->pWC, pSrc->iCursor, saved_nEq,
                        opMask, pProbe);
  pNew->rSetup = 0;
  rSize = pProbe->aiRowLogEst[0];
  rLogSize = estLog(rSize);
  for(; rc==SQLITE_OK && pTerm!=0; pTerm = whereScanNext(&scan)){
    u16 eOp = pTerm->eOperator;   /* Shorthand for pTerm->eOperator */
    LogEst rCostIdx;
    LogEst nOutUnadjusted;        /* nOut before IN() and WHERE adjustments */
    int nIn = 0;
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
    int nRecValid = pBuilder->nRecValid;
#endif
    if( (eOp==WO_ISNULL || (pTerm->wtFlags&TERM_VNULL)!=0)
     && indexColumnNotNull(pProbe, saved_nEq)
    ){
      continue; /* ignore IS [NOT] NULL constraints on NOT NULL columns */
    }
    if( pTerm->prereqRight & pNew->maskSelf ) continue;

    /* Do not allow the upper bound of a LIKE optimization range constraint
    ** to mix with a lower range bound from some other source */

        /* "x IN (value, value, ...)" */
        nIn = sqlite3LogEst(pExpr->x.pList->nExpr);
      }
      assert( nIn>0 );  /* RHS always has 2 or more terms...  The parser
                        ** changes "x IN (?)" into "x=?". */

    }else if( eOp & (WO_EQ|WO_IS) ){
      int iCol = pProbe->aiColumn[saved_nEq];
      pNew->wsFlags |= WHERE_COLUMN_EQ;
      assert( saved_nEq==pNew->u.btree.nEq );
      if( iCol==(-1) || (iCol>0 && nInMul==0 && saved_nEq==pProbe->nKeyCol-1) ){
        if( iCol>=0 && pProbe->uniqNotNull==0 ){
          pNew->wsFlags |= WHERE_UNQ_WANTED;
        }else{
          pNew->wsFlags |= WHERE_ONEROW;
        }
      }
    }else if( eOp & WO_ISNULL ){

      ** data, using some other estimate.  */
      whereRangeScanEst(pParse, pBuilder, pBtm, pTop, pNew);
    }else{
      int nEq = ++pNew->u.btree.nEq;
      assert( eOp & (WO_ISNULL|WO_EQ|WO_IN|WO_IS) );

      assert( pNew->nOut==saved_nOut );
      if( pTerm->truthProb<=0 && pProbe->aiColumn[saved_nEq]>=0 ){
        assert( (eOp & WO_IN) || nIn==0 );
        testcase( eOp & WO_IN );
        pNew->nOut += pTerm->truthProb;
        pNew->nOut -= nIn;
      }else{
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
        tRowcnt nOut = 0;

      assert( pLoop->aLTermSpace==pLoop->aLTerm );
      if( !IsUniqueIndex(pIdx)
       || pIdx->pPartIdxWhere!=0 
       || pIdx->nKeyCol>ArraySize(pLoop->aLTermSpace) 
      ) continue;
      opMask = pIdx->uniqNotNull ? (WO_EQ|WO_IS) : WO_EQ;
      for(j=0; j<pIdx->nKeyCol; j++){
        pTerm = sqlite3WhereFindTerm(pWC, iCur, j, 0, opMask, pIdx);
        if( pTerm==0 ) break;
        testcase( pTerm->eOperator & WO_IS );
        pLoop->aLTerm[j] = pTerm;
      }
      if( j!=pIdx->nKeyCol ) continue;
      pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_ONEROW|WHERE_INDEXED;
      if( pIdx->isCovering || (pItem->colUsed & ~columnsInIndex(pIdx))==0 ){

    if( wctrlFlags & WHERE_WANT_DISTINCT ){
      pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
    }
  }

  /* Assign a bit from the bitmask to every term in the FROM clause.
  **
  ** The N-th term of the FROM clause is assigned a bitmask of 1<<N.
  **
  ** The rule of the previous sentence ensures thta if X is the bitmask for
  ** a table T, then X-1 is the bitmask for all other tables to the left of T.



  ** Knowing the bitmask for all tables to the left of a left join is
  ** important.  Ticket #3015.
  **
  ** Note that bitmasks are created for all pTabList->nSrc tables in
  ** pTabList, not just the first nTabList tables.  nTabList is normally
  ** equal to pTabList->nSrc but might be shortened to 1 if the
  ** WHERE_ONETABLE_ONLY flag is set.
  */
  for(ii=0; ii<pTabList->nSrc; ii++){
    createMask(pMaskSet, pTabList->a[ii].iCursor);
    sqlite3WhereTabFuncArgs(pParse, &pTabList->a[ii], &pWInfo->sWC);
  }
#ifdef SQLITE_DEBUG


  for(ii=0; ii<pTabList->nSrc; ii++){
    Bitmask m = sqlite3WhereGetMask(pMaskSet, pTabList->a[ii].iCursor);
    assert( m==MASKBIT(ii) );


  }
#endif

  /* Analyze all of the subexpressions. */
  sqlite3WhereExprAnalyze(pTabList, &pWInfo->sWC);
  if( db->mallocFailed ) goto whereBeginError;

** An instance of the WhereScan object is used as an iterator for locating
** terms in the WHERE clause that are useful to the query planner.
*/
struct WhereScan {
  WhereClause *pOrigWC;      /* Original, innermost WhereClause */
  WhereClause *pWC;          /* WhereClause currently being scanned */
  char *zCollName;           /* Required collating sequence, if not NULL */
  Expr *pIdxExpr;            /* Search for this index expression */
  char idxaff;               /* Must match this affinity, if zCollName!=NULL */
  unsigned char nEquiv;      /* Number of entries in aEquiv[] */
  unsigned char iEquiv;      /* Next unused slot in aEquiv[] */
  u32 opMask;                /* Acceptable operators */
  int k;                     /* Resume scanning at this->pWC->a[this->k] */
  int aiCur[11];             /* Cursors in the equivalence class */
  i16 aiColumn[11];          /* Corresponding column number in the eq-class */

  const char *zOp             /* Name of the operator */
){
  if( iTerm ) sqlite3StrAccumAppend(pStr, " AND ", 5);
  sqlite3StrAccumAppendAll(pStr, zColumn);
  sqlite3StrAccumAppend(pStr, zOp, 1);
  sqlite3StrAccumAppend(pStr, "?", 1);
}

/*
** Return the name of the i-th column of the pIdx index.
*/
static const char *explainIndexColumnName(Index *pIdx, int i){
  i = pIdx->aiColumn[i];
  if( i==(-2) ) return "<expr>";
  if( i==(-1) ) return "rowid";
  return pIdx->pTable->aCol[i].zName;
}

/*
** Argument pLevel describes a strategy for scanning table pTab. This 
** function appends text to pStr that describes the subset of table
** rows scanned by the strategy in the form of an SQL expression.
**
** For example, if the query:
**
**   SELECT * FROM t1 WHERE a=1 AND b>2;
**
** is run and there is an index on (a, b), then this function returns a
** string similar to:
**
**   "a=? AND b>?"
*/
static void explainIndexRange(StrAccum *pStr, WhereLoop *pLoop, Table *pTab){
  Index *pIndex = pLoop->u.btree.pIndex;
  u16 nEq = pLoop->u.btree.nEq;
  u16 nSkip = pLoop->nSkip;
  int i, j;



  if( nEq==0 && (pLoop->wsFlags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ) return;
  sqlite3StrAccumAppend(pStr, " (", 2);
  for(i=0; i<nEq; i++){
    const char *z = explainIndexColumnName(pIndex, i);
    if( i ) sqlite3StrAccumAppend(pStr, " AND ", 5);
    sqlite3XPrintf(pStr, 0, i>=nSkip ? "%s=?" : "ANY(%s)", z);
  }

  j = i;
  if( pLoop->wsFlags&WHERE_BTM_LIMIT ){
    const char *z = explainIndexColumnName(pIndex, i);
    explainAppendTerm(pStr, i++, z, ">");
  }
  if( pLoop->wsFlags&WHERE_TOP_LIMIT ){
    const char *z = explainIndexColumnName(pIndex, j);
    explainAppendTerm(pStr, i, z, "<");
  }
  sqlite3StrAccumAppend(pStr, ")", 1);
}

/*
** This function is a no-op unless currently processing an EXPLAIN QUERY PLAN

        mask |= sqlite3WhereExprUsage(pMaskSet, pSrc->a[i].pOn);
      }
    }
    pS = pS->pPrior;
  }
  return mask;
}

/*
** Expression pExpr is one operand of a comparison operator that might
** be useful for indexing.  This routine checks to see if pExpr appears
** in any index.  Return TRUE (1) if pExpr is an indexed term and return
** FALSE (0) if not.  If TRUE is returned, also set *piCur to the cursor
** number of the table that is indexed and *piColumn to the column number
** of the column that is indexed, or -2 if an expression is being indexed.
**
** If pExpr is a TK_COLUMN column reference, then this routine always returns
** true even if that particular column is not indexed, because the column
** might be added to an automatic index later.
*/
static int exprMightBeIndexed(
  SrcList *pFrom,        /* The FROM clause */
  Bitmask mPrereq,       /* Bitmask of FROM clause terms referenced by pExpr */
  Expr *pExpr,           /* An operand of a comparison operator */
  int *piCur,            /* Write the referenced table cursor number here */
  int *piColumn          /* Write the referenced table column number here */
){
  Index *pIdx;
  int i;
  int iCur;
  if( pExpr->op==TK_COLUMN ){
    *piCur = pExpr->iTable;
    *piColumn = pExpr->iColumn;
    return 1;
  }
  if( mPrereq==0 ) return 0;                 /* No table references */
  if( (mPrereq&(mPrereq-1))!=0 ) return 0;   /* Refs more than one table */
  for(i=0; mPrereq>1; i++, mPrereq>>=1){}
  iCur = pFrom->a[i].iCursor;
  for(pIdx=pFrom->a[i].pTab->pIndex; pIdx; pIdx=pIdx->pNext){
    if( pIdx->aColExpr==0 ) continue;
    for(i=0; i<pIdx->nKeyCol; i++){
      if( pIdx->aiColumn[i]!=(-2) ) continue;
      if( sqlite3ExprCompare(pExpr, pIdx->aColExpr->a[i].pExpr, iCur)==0 ){
        *piCur = iCur;
        *piColumn = -2;
        return 1;
      }
    }
  }
  return 0;
}

/*
** The input to this routine is an WhereTerm structure with only the
** "pExpr" field filled in.  The job of this routine is to analyze the
** subexpression and populate all the other fields of the WhereTerm
** structure.
**

                       ** on left table of a LEFT JOIN.  Ticket #3015 */
  }
  pTerm->prereqAll = prereqAll;
  pTerm->leftCursor = -1;
  pTerm->iParent = -1;
  pTerm->eOperator = 0;
  if( allowedOp(op) ){
    int iCur, iColumn;
    Expr *pLeft = sqlite3ExprSkipCollate(pExpr->pLeft);
    Expr *pRight = sqlite3ExprSkipCollate(pExpr->pRight);
    u16 opMask = (pTerm->prereqRight & prereqLeft)==0 ? WO_ALL : WO_EQUIV;
    if( exprMightBeIndexed(pSrc, prereqLeft, pLeft, &iCur, &iColumn) ){
      pTerm->leftCursor = iCur;
      pTerm->u.leftColumn = iColumn;
      pTerm->eOperator = operatorMask(op) & opMask;
    }
    if( op==TK_IS ) pTerm->wtFlags |= TERM_IS;
    if( pRight 
     && exprMightBeIndexed(pSrc, pTerm->prereqRight, pRight, &iCur, &iColumn)
    ){
      WhereTerm *pNew;
      Expr *pDup;
      u16 eExtraOp = 0;        /* Extra bits for pNew->eOperator */
      if( pTerm->leftCursor>=0 ){
        int idxNew;
        pDup = sqlite3ExprDup(db, pExpr, 0);
        if( db->mallocFailed ){

        }
      }else{
        pDup = pExpr;
        pNew = pTerm;
      }
      exprCommute(pParse, pDup);
      pLeft = sqlite3ExprSkipCollate(pDup->pLeft);
      pNew->leftCursor = iCur;
      pNew->u.leftColumn = iColumn;
      testcase( (prereqLeft | extraRight) != prereqLeft );
      pNew->prereqRight = prereqLeft | extraRight;
      pNew->prereqAll = prereqAll;
      pNew->eOperator = (operatorMask(pDup->op) + eExtraOp) & opMask;
    }
  }

  set v [catch {execsql {CREATE INDEX index1 ON test1(f1)}} msg]
  lappend v $msg
} {1 {no such table: main.test1}}

# Try adding an index on a column of a table where the table
# exists but the column does not.
#
do_test index-2.1b {
  execsql {CREATE TABLE test1(f1 int, f2 int, f3 int)}
  set v [catch {execsql {CREATE INDEX index1 ON test1(f4)}} msg]
  lappend v $msg
} {1 {no such column: f4}}

# Try an index with some columns that match and others that do now.
#
do_test index-2.2 {
  set v [catch {execsql {CREATE INDEX index1 ON test1(f1, f2, f4, f3)}} msg]
  execsql {DROP TABLE test1}
  lappend v $msg
} {1 {no such column: f4}}

# Try creating a bunch of indices on the same table
#
set r {}
for {set i 1} {$i<100} {incr i} {
  lappend r [format index%02d $i]
}

# 2015-08-31
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing indexes on expressions.
#

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

do_execsql_test indexexpr1-100 {
  CREATE TABLE t1(a,b,c);
  INSERT INTO t1(a,b,c)
      /*  123456789 123456789 123456789 123456789 123456789 123456789 */ 
  VALUES('In_the_beginning_was_the_Word',1,1),
        ('and_the_Word_was_with_God',1,2),
        ('and_the_Word_was_God',1,3),
        ('The_same_was_in_the_beginning_with_God',2,1),
        ('All_things_were_made_by_him',3,1),
        ('and_without_him_was_not_any_thing_made_that_was_made',3,2);
  CREATE INDEX t1a1 ON t1(substr(a,1,12));
} {}
do_execsql_test indexexpr1-110 {
  SELECT b, c, '|' FROM t1 WHERE substr(a,1,12)=='and_the_Word' ORDER BY b, c;
} {1 2 | 1 3 |}
do_execsql_test indexexpr1-110eqp {
  EXPLAIN QUERY PLAN
  SELECT b, c, '|' FROM t1 WHERE substr(a,1,12)=='and_the_Word' ORDER BY b, c;
} {/USING INDEX t1a1/}
do_execsql_test indexexpr1-120 {
  SELECT b, c, '|' FROM t1 WHERE 'and_the_Word'==substr(a,1,12) ORDER BY b, c;
} {1 2 | 1 3 |}
do_execsql_test indexexpr1-120eqp {
  EXPLAIN QUERY PLAN
  SELECT b, c, '|' FROM t1 WHERE 'and_the_Word'==substr(a,1,12) ORDER BY b, c;
} {/USING INDEX t1a1/}

do_execsql_test indexexpr1-130 {
  CREATE INDEX t1ba ON t1(b,substr(a,2,3),c);
  SELECT c FROM t1 WHERE b=1 AND substr(a,2,3)='nd_' ORDER BY c;
} {2 3}
do_execsql_test indexexpr1-130eqp {
  EXPLAIN QUERY PLAN
  SELECT c FROM t1 WHERE b=1 AND substr(a,2,3)='nd_' ORDER BY c;
} {/USING INDEX t1ba/}

do_execsql_test indexexpr1-140 {
  SELECT rowid, substr(a,b,3), '|' FROM t1 ORDER BY 2;
} {1 In_ | 2 and | 3 and | 6 d_w | 4 he_ | 5 l_t |}
do_execsql_test indexexpr1-141 {
  CREATE INDEX t1abx ON t1(substr(a,b,3));
  SELECT rowid FROM t1 WHERE substr(a,b,3)<='and' ORDER BY +rowid;
} {1 2 3}
do_execsql_test indexexpr1-141eqp {
  EXPLAIN QUERY PLAN
  SELECT rowid FROM t1 WHERE substr(a,b,3)<='and' ORDER BY +rowid;
} {/USING INDEX t1abx/}
do_execsql_test indexexpr1-142 {
  SELECT rowid FROM t1 WHERE +substr(a,b,3)<='and' ORDER BY +rowid;
} {1 2 3}
do_execsql_test indexexpr1-150 {
  SELECT rowid FROM t1 WHERE substr(a,b,3) IN ('and','l_t','xyz')
   ORDER BY +rowid;
} {2 3 5}
do_execsql_test indexexpr1-150eqp {
  EXPLAIN QUERY PLAN
  SELECT rowid FROM t1 WHERE substr(a,b,3) IN ('and','l_t','xyz')
   ORDER BY +rowid;
} {/USING INDEX t1abx/}

do_execsql_test indexexpr1-160 {
  ALTER TABLE t1 ADD COLUMN d;
  UPDATE t1 SET d=length(a);
  CREATE INDEX t1a2 ON t1(SUBSTR(a, 27, 3)) WHERE d>=29;
  SELECT rowid, b, c FROM t1
   WHERE substr(a,27,3)=='ord' AND d>=29;
} {1 1 1}
do_execsql_test indexexpr1-160eqp {
  EXPLAIN QUERY PLAN
  SELECT rowid, b, c FROM t1
   WHERE substr(a,27,3)=='ord' AND d>=29;
} {/USING INDEX t1a2/}


do_execsql_test indexexpr1-200 {
  DROP TABLE t1;
  CREATE TABLE t1(id ANY PRIMARY KEY, a,b,c) WITHOUT ROWID;
  INSERT INTO t1(id,a,b,c)
  VALUES(1,'In_the_beginning_was_the_Word',1,1),
        (2,'and_the_Word_was_with_God',1,2),
        (3,'and_the_Word_was_God',1,3),
        (4,'The_same_was_in_the_beginning_with_God',2,1),
        (5,'All_things_were_made_by_him',3,1),
        (6,'and_without_him_was_not_any_thing_made_that_was_made',3,2);
  CREATE INDEX t1a1 ON t1(substr(a,1,12));
} {}
do_execsql_test indexexpr1-210 {
  SELECT b, c, '|' FROM t1 WHERE substr(a,1,12)=='and_the_Word' ORDER BY b, c;
} {1 2 | 1 3 |}
do_execsql_test indexexpr1-210eqp {
  EXPLAIN QUERY PLAN
  SELECT b, c, '|' FROM t1 WHERE substr(a,1,12)=='and_the_Word' ORDER BY b, c;
} {/USING INDEX t1a1/}
do_execsql_test indexexpr1-220 {
  SELECT b, c, '|' FROM t1 WHERE 'and_the_Word'==substr(a,1,12) ORDER BY b, c;
} {1 2 | 1 3 |}
do_execsql_test indexexpr1-220eqp {
  EXPLAIN QUERY PLAN
  SELECT b, c, '|' FROM t1 WHERE 'and_the_Word'==substr(a,1,12) ORDER BY b, c;
} {/USING INDEX t1a1/}

do_execsql_test indexexpr1-230 {
  CREATE INDEX t1ba ON t1(b,substr(a,2,3),c);
  SELECT c FROM t1 WHERE b=1 AND substr(a,2,3)='nd_' ORDER BY c;
} {2 3}
do_execsql_test indexexpr1-230eqp {
  EXPLAIN QUERY PLAN
  SELECT c FROM t1 WHERE b=1 AND substr(a,2,3)='nd_' ORDER BY c;
} {/USING INDEX t1ba/}

do_execsql_test indexexpr1-240 {
  SELECT id, substr(a,b,3), '|' FROM t1 ORDER BY 2;
} {1 In_ | 2 and | 3 and | 6 d_w | 4 he_ | 5 l_t |}
do_execsql_test indexexpr1-241 {
  CREATE INDEX t1abx ON t1(substr(a,b,3));
  SELECT id FROM t1 WHERE substr(a,b,3)<='and' ORDER BY +id;
} {1 2 3}
do_execsql_test indexexpr1-241eqp {
  EXPLAIN QUERY PLAN
  SELECT id FROM t1 WHERE substr(a,b,3)<='and' ORDER BY +id;
} {/USING INDEX t1abx/}
do_execsql_test indexexpr1-242 {
  SELECT id FROM t1 WHERE +substr(a,b,3)<='and' ORDER BY +id;
} {1 2 3}
do_execsql_test indexexpr1-250 {
  SELECT id FROM t1 WHERE substr(a,b,3) IN ('and','l_t','xyz')
   ORDER BY +id;
} {2 3 5}
do_execsql_test indexexpr1-250eqp {
  EXPLAIN QUERY PLAN
  SELECT id FROM t1 WHERE substr(a,b,3) IN ('and','l_t','xyz')
   ORDER BY +id;
} {/USING INDEX t1abx/}

do_execsql_test indexexpr1-260 {
  ALTER TABLE t1 ADD COLUMN d;
  UPDATE t1 SET d=length(a);
  CREATE INDEX t1a2 ON t1(SUBSTR(a, 27, 3)) WHERE d>=29;
  SELECT id, b, c FROM t1
   WHERE substr(a,27,3)=='ord' AND d>=29;
} {1 1 1}
do_execsql_test indexexpr1-260eqp {
  EXPLAIN QUERY PLAN
  SELECT id, b, c FROM t1
   WHERE substr(a,27,3)=='ord' AND d>=29;
} {/USING INDEX t1a2/}


do_catchsql_test indexexpr1-300 {
  CREATE TABLE t2(a,b,c);
  CREATE INDEX t2x1 ON t2(a,b+random());
} {1 {non-deterministic functions prohibited in index expressions}}
do_catchsql_test indexexpr1-301 {
  CREATE INDEX t2x1 ON t2(a+julianday('now'));
} {1 {non-deterministic functions prohibited in index expressions}}
do_catchsql_test indexexpr1-310 {
  CREATE INDEX t2x2 ON t2(a,b+(SELECT 15));
} {1 {subqueries prohibited in index expressions}}
do_catchsql_test indexexpr1-320 {
  CREATE TABLE e1(x,y,UNIQUE(y,substr(x,1,5)));
} {1 {expressions prohibited in PRIMARY KEY and UNIQUE constraints}}
do_catchsql_test indexexpr1-330 {
  CREATE TABLE e1(x,y,PRIMARY KEY(y,substr(x,1,5)));
} {1 {expressions prohibited in PRIMARY KEY and UNIQUE constraints}}
do_catchsql_test indexexpr1-331 {
  CREATE TABLE e1(x,y,PRIMARY KEY(y,substr(x,1,5))) WITHOUT ROWID;
} {1 {expressions prohibited in PRIMARY KEY and UNIQUE constraints}}
do_catchsql_test indexexpr1-340 {
  CREATE TABLE e1(x,y,FOREIGN KEY(substr(y,1,5)) REFERENCES t1);
} {1 {near "(": syntax error}}

do_execsql_test indexexpr1-400 {
  CREATE TABLE t3(a,b,c);
  WITH RECURSIVE c(x) AS (VALUES(1) UNION SELECT x+1 FROM c WHERE x<30)
  INSERT INTO t3(a,b,c)
    SELECT x, printf('ab%04xyz',x), random() FROM c;
  CREATE UNIQUE INDEX t3abc ON t3(CAST(a AS text), b, substr(c,1,3));
  SELECT a FROM t3 WHERE CAST(a AS text)<='10' ORDER BY +a;
} {1 10}
do_catchsql_test indexexpr1-410 {
  INSERT INTO t3 SELECT * FROM t3 WHERE rowid=10;
} {1 {UNIQUE constraint failed: index 't3abc'}}

finish_test

do_test rowid-2.8 {
  global x2rowid
  set sql "UPDATE t1 SET x=3 WHERE _rowid_==$x2rowid(3)"
  execsql $sql
  execsql {SELECT x FROM t1 ORDER BY x}
} {1 3 5 7 9}

if 0 {  # With the index-on-expressions enhancement, creating
        # an index on ROWID has become possible.
# We cannot index by ROWID
#
do_test rowid-2.9 {
  set v [catch {execsql {CREATE INDEX idxt1 ON t1(rowid)}} msg]
  lappend v $msg
} {1 {table t1 has no column named rowid}}
do_test rowid-2.10 {
  set v [catch {execsql {CREATE INDEX idxt1 ON t1(_rowid_)}} msg]
  lappend v $msg
} {1 {table t1 has no column named _rowid_}}
do_test rowid-2.11 {
  set v [catch {execsql {CREATE INDEX idxt1 ON t1(oid)}} msg]
  lappend v $msg
} {1 {table t1 has no column named oid}}
do_test rowid-2.12 {
  set v [catch {execsql {CREATE INDEX idxt1 ON t1(x, rowid)}} msg]
  lappend v $msg
} {1 {table t1 has no column named rowid}}
}

# Columns defined in the CREATE statement override the buildin ROWID
# column names.
#
do_test rowid-3.1 {
  execsql {
    CREATE TABLE t2(rowid int, x int, y int);