**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.21.0"
#define SQLITE_VERSION_NUMBER 3021000
#define SQLITE_SOURCE_ID      "2017-10-02 02:52:54 c9104b59c7ed360291f7f6fc8caae938e9840c77620d598e4096f78183bf807a"

/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros

** sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS,...) interface to
** selectively disable various optimizations.
*/
#define SQLITE_QueryFlattener 0x0001   /* Query flattening */
#define SQLITE_ColumnCache    0x0002   /* Column cache */
#define SQLITE_GroupByOrder   0x0004   /* GROUPBY cover of ORDERBY */
#define SQLITE_FactorOutConst 0x0008   /* Constant factoring */

#define SQLITE_DistinctOpt    0x0010   /* DISTINCT using indexes */
#define SQLITE_CoverIdxScan   0x0020   /* Covering index scans */
#define SQLITE_OrderByIdxJoin 0x0040   /* ORDER BY of joins via index */

#define SQLITE_Transitive     0x0080   /* Transitive constraints */
#define SQLITE_OmitNoopJoin   0x0100   /* Omit unused tables in joins */
#define SQLITE_CountOfView    0x0200   /* The count-of-view optimization */
#define SQLITE_CursorHints    0x0400   /* Add OP_CursorHint opcodes */
#define SQLITE_Stat34         0x0800   /* Use STAT3 or STAT4 data */
   /* TH3 expects the Stat34  ^^^^^^ value to be 0x0800.  Don't change it */

#define SQLITE_AllOpts        0xffff   /* All optimizations */

/*
** Macros for testing whether or not optimizations are enabled or disabled.
*/
#define OptimizationDisabled(db, mask)  (((db)->dbOptFlags&(mask))!=0)
#define OptimizationEnabled(db, mask)   (((db)->dbOptFlags&(mask))==0)

#endif

SQLITE_PRIVATE const char *sqlite3ErrStr(int);
SQLITE_PRIVATE int sqlite3ReadSchema(Parse *pParse);
SQLITE_PRIVATE CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char*,int);
SQLITE_PRIVATE CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char*zName);
SQLITE_PRIVATE CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
SQLITE_PRIVATE CollSeq *sqlite3ExprNNCollSeq(Parse *pParse, Expr *pExpr);
SQLITE_PRIVATE int sqlite3ExprCollSeqMatch(Parse*,Expr*,Expr*);
SQLITE_PRIVATE Expr *sqlite3ExprAddCollateToken(Parse *pParse, Expr*, const Token*, int);
SQLITE_PRIVATE Expr *sqlite3ExprAddCollateString(Parse*,Expr*,const char*);
SQLITE_PRIVATE Expr *sqlite3ExprSkipCollate(Expr*);
SQLITE_PRIVATE int sqlite3CheckCollSeq(Parse *, CollSeq *);
SQLITE_PRIVATE int sqlite3CheckObjectName(Parse *, const char *);
SQLITE_PRIVATE void sqlite3VdbeSetChanges(sqlite3 *, int);
SQLITE_PRIVATE int sqlite3AddInt64(i64*,i64);

    extendedParameters.dwSize = sizeof(CREATEFILE2_EXTENDED_PARAMETERS);
    extendedParameters.dwFileAttributes =
            dwFlagsAndAttributes & FILE_ATTRIBUTE_MASK;
    extendedParameters.dwFileFlags = dwFlagsAndAttributes & FILE_FLAG_MASK;
    extendedParameters.dwSecurityQosFlags = SECURITY_ANONYMOUS;
    extendedParameters.lpSecurityAttributes = NULL;
    extendedParameters.hTemplateFile = NULL;
    do{
      h = osCreateFile2((LPCWSTR)zConverted,
                        dwDesiredAccess,
                        dwShareMode,
                        dwCreationDisposition,
                        &extendedParameters);

      if( h!=INVALID_HANDLE_VALUE ) break;
      if( isReadWrite ){
        int isRO = 0;
        int rc2 = winAccess(pVfs, zName, SQLITE_ACCESS_READ, &isRO);
        if( rc2==SQLITE_OK && isRO ) break;
      }
    }while( winRetryIoerr(&cnt, &lastErrno) );
#else
    do{
      h = osCreateFileW((LPCWSTR)zConverted,
                        dwDesiredAccess,
                        dwShareMode, NULL,
                        dwCreationDisposition,
                        dwFlagsAndAttributes,
                        NULL);
      if( h!=INVALID_HANDLE_VALUE ) break;
      if( isReadWrite ){
        int isRO = 0;
        int rc2 = winAccess(pVfs, zName, SQLITE_ACCESS_READ, &isRO);
        if( rc2==SQLITE_OK && isRO ) break;
      }
    }while( winRetryIoerr(&cnt, &lastErrno) );
#endif
  }
#ifdef SQLITE_WIN32_HAS_ANSI
  else{
    do{
      h = osCreateFileA((LPCSTR)zConverted,
                        dwDesiredAccess,
                        dwShareMode, NULL,
                        dwCreationDisposition,
                        dwFlagsAndAttributes,
                        NULL);
      if( h!=INVALID_HANDLE_VALUE ) break;


      if( isReadWrite ){
        int isRO = 0;
        int rc2 = winAccess(pVfs, zName, SQLITE_ACCESS_READ, &isRO);
        if( rc2==SQLITE_OK && isRO ) break;
      }
    }while( winRetryIoerr(&cnt, &lastErrno) );
  }
#endif
  winLogIoerr(cnt, __LINE__);

  OSTRACE(("OPEN file=%p, name=%s, access=%lx, rc=%s\n", h, zUtf8Name,
           dwDesiredAccess, (h==INVALID_HANDLE_VALUE) ? "failed" : "ok"));

      if( 0==iFree2 || (data[iFree2]==0 && data[iFree2+1]==0) ){
        u8 *pEnd = &data[cellOffset + nCell*2];
        u8 *pAddr;
        int sz2 = 0;
        int sz = get2byte(&data[iFree+2]);
        int top = get2byte(&data[hdr+5]);
        if( top>=iFree ){
          return SQLITE_CORRUPT_PGNO(pPage->pgno);
        }
        if( iFree2 ){
          assert( iFree+sz<=iFree2 ); /* Verified by pageFindSlot() */
          sz2 = get2byte(&data[iFree2+2]);
          assert( iFree+sz+sz2+iFree2-(iFree+sz) <= usableSize );
          memmove(&data[iFree+sz+sz2], &data[iFree+sz], iFree2-(iFree+sz));
          sz += sz2;
        }

  BtCursor *pCur,   /* Cursor pointing at record to retrieve. */
  u32 offset,       /* Offset from the start of data to return bytes from. */
  u32 amt,          /* Number of bytes to return. */
  Mem *pMem         /* OUT: Return data in this Mem structure. */
){
  int rc;
  pMem->flags = MEM_Null;
  if( SQLITE_OK==(rc = sqlite3VdbeMemClearAndResize(pMem, amt+1)) ){
    rc = sqlite3BtreePayload(pCur, offset, amt, pMem->z);
    if( rc==SQLITE_OK ){
      pMem->z[amt] = 0;   /* Overrun area used when reading malformed records */
      pMem->flags = MEM_Blob;
      pMem->n = (int)amt;
    }else{
      sqlite3VdbeMemRelease(pMem);
    }
  }
  return rc;

  return pExpr;
}

/*
** Return the collation sequence for the expression pExpr. If
** there is no defined collating sequence, return NULL.
**
** See also: sqlite3ExprNNCollSeq()
**
** The sqlite3ExprNNCollSeq() works the same exact that it returns the
** default collation if pExpr has no defined collation.
**
** The collating sequence might be determined by a COLLATE operator
** or by the presence of a column with a defined collating sequence.
** COLLATE operators take first precedence.  Left operands take
** precedence over right operands.
*/
SQLITE_PRIVATE CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
  sqlite3 *db = pParse->db;

    }
  }
  if( sqlite3CheckCollSeq(pParse, pColl) ){ 
    pColl = 0;
  }
  return pColl;
}

/*
** Return the collation sequence for the expression pExpr. If
** there is no defined collating sequence, return a pointer to the
** defautl collation sequence.
**
** See also: sqlite3ExprCollSeq()
**
** The sqlite3ExprCollSeq() routine works the same except that it
** returns NULL if there is no defined collation.
*/
SQLITE_PRIVATE CollSeq *sqlite3ExprNNCollSeq(Parse *pParse, Expr *pExpr){
  CollSeq *p = sqlite3ExprCollSeq(pParse, pExpr);
  if( p==0 ) p = pParse->db->pDfltColl;
  assert( p!=0 );
  return p;
}

/*
** Return TRUE if the two expressions have equivalent collating sequences.
*/
SQLITE_PRIVATE int sqlite3ExprCollSeqMatch(Parse *pParse, Expr *pE1, Expr *pE2){
  CollSeq *pColl1 = sqlite3ExprNNCollSeq(pParse, pE1);
  CollSeq *pColl2 = sqlite3ExprNNCollSeq(pParse, pE2);
  return sqlite3StrICmp(pColl1->zName, pColl2->zName)==0;
}

/*
** pExpr is an operand of a comparison operator.  aff2 is the
** type affinity of the other operand.  This routine returns the
** type affinity that should be used for the comparison operator.
*/
SQLITE_PRIVATE char sqlite3CompareAffinity(Expr *pExpr, char aff2){

/*
** Return the bitwise-OR of all Expr.flags fields in the given
** ExprList.
*/
SQLITE_PRIVATE u32 sqlite3ExprListFlags(const ExprList *pList){
  int i;
  u32 m = 0;
  assert( pList!=0 );
  for(i=0; i<pList->nExpr; i++){
     Expr *pExpr = pList->a[i].pExpr;
     assert( pExpr!=0 );
     m |= pExpr->flags;

  }
  return m;
}

/*
** This is a SELECT-node callback for the expression walker that
** always "fails".  By "fail" in this case, we mean set

  int i;

  /* Check if pExpr is identical to any GROUP BY term. If so, consider
  ** it constant.  */
  for(i=0; i<pGroupBy->nExpr; i++){
    Expr *p = pGroupBy->a[i].pExpr;
    if( sqlite3ExprCompare(0, pExpr, p, -1)<2 ){
      CollSeq *pColl = sqlite3ExprNNCollSeq(pWalker->pParse, p);
      if( sqlite3_stricmp("BINARY", pColl->zName)==0 ){
        return WRC_Prune;
      }
    }
  }

  /* Check if pExpr is a sub-select. If so, consider it variable. */
  if( ExprHasProperty(pExpr, EP_xIsSelect) ){

  Select standin;
  pNew = sqlite3DbMallocRawNN(pParse->db, sizeof(*pNew) );
  if( pNew==0 ){
    assert( pParse->db->mallocFailed );
    pNew = &standin;
  }
  if( pEList==0 ){
    pEList = sqlite3ExprListAppend(pParse, 0,
                                   sqlite3Expr(pParse->db,TK_ASTERISK,0));
  }
  pNew->pEList = pEList;
  pNew->op = TK_SELECT;
  pNew->selFlags = selFlags;
  pNew->iLimit = 0;
  pNew->iOffset = 0;
#if SELECTTRACE_ENABLED

  pNew->pHaving = pHaving;
  pNew->pOrderBy = pOrderBy;
  pNew->pPrior = 0;
  pNew->pNext = 0;
  pNew->pLimit = pLimit;
  pNew->pOffset = pOffset;
  pNew->pWith = 0;
  assert( pOffset==0 || pLimit!=0 || pParse->nErr>0
                     || pParse->db->mallocFailed!=0 );
  if( pParse->db->mallocFailed ) {
    clearSelect(pParse->db, pNew, pNew!=&standin);
    pNew = 0;
  }else{
    assert( pNew->pSrc!=0 || pParse->nErr>0 );
  }
  assert( pNew!=&standin );

          p->pEList->a[j-1].u.x.iOrderByCol = i+1-pSort->nOBSat;
        }
      }
      regOrig = 0;
      assert( eDest==SRT_Set || eDest==SRT_Mem 
           || eDest==SRT_Coroutine || eDest==SRT_Output );
    }
    nResultCol = sqlite3ExprCodeExprList(pParse,p->pEList,regResult,
                                         0,ecelFlags);
  }

  /* If the DISTINCT keyword was present on the SELECT statement
  ** and this row has been seen before, then do not make this row
  ** part of the result.
  */
  if( hasDistinct ){

  int i;

  nExpr = pList->nExpr;
  pInfo = sqlite3KeyInfoAlloc(db, nExpr-iStart, nExtra+1);
  if( pInfo ){
    assert( sqlite3KeyInfoIsWriteable(pInfo) );
    for(i=iStart, pItem=pList->a+iStart; i<nExpr; i++, pItem++){



      pInfo->aColl[i-iStart] = sqlite3ExprNNCollSeq(pParse, pItem->pExpr);
      pInfo->aSortOrder[i-iStart] = pItem->sortOrder;
    }
  }
  return pInfo;
}

/*

** other modes for legacy:
**
**    short=OFF, full=OFF:      Column name is the text of the expression has it
**                              originally appears in the SELECT statement.  In
**                              other words, the zSpan of the result expression.
**
**    short=ON, full=OFF:       (This is the default setting).  If the result
**                              refers directly to a table column, then the
**                              result column name is just the table column
**                              name: COLUMN.  Otherwise use zSpan.
**
**    full=ON, short=ANY:       If the result refers directly to a table column,
**                              then the result column name with the table name
**                              prefix, ex: TABLE.COLUMN.  Otherwise use zSpan.
*/
static void generateColumnNames(
  Parse *pParse,      /* Parser context */

  srcName = (db->flags & SQLITE_ShortColNames)!=0 || fullName;
  sqlite3VdbeSetNumCols(v, pEList->nExpr);
  for(i=0; i<pEList->nExpr; i++){
    Expr *p = pEList->a[i].pExpr;

    assert( p!=0 );
    assert( p->op!=TK_AGG_COLUMN );  /* Agg processing has not run yet */
    assert( p->op!=TK_COLUMN || p->pTab!=0 ); /* Covering idx not yet coded */
    if( pEList->a[i].zName ){
      /* An AS clause always takes first priority */
      char *zName = pEList->a[i].zName;
      sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_TRANSIENT);
    }else if( srcName && p->op==TK_COLUMN ){
      char *zCol;
      int iCol = p->iColumn;

** of the subquery rather the result set of the subquery.
*/
static Expr *substExpr(
  SubstContext *pSubst,  /* Description of the substitution */
  Expr *pExpr            /* Expr in which substitution occurs */
){
  if( pExpr==0 ) return 0;
  if( ExprHasProperty(pExpr, EP_FromJoin)
   && pExpr->iRightJoinTable==pSubst->iTable
  ){
    pExpr->iRightJoinTable = pSubst->iNewTable;
  }
  if( pExpr->op==TK_COLUMN && pExpr->iTable==pSubst->iTable ){
    if( pExpr->iColumn<0 ){
      pExpr->op = TK_NULL;
    }else{
      Expr *pNew;

**     SELECT x+y AS a FROM t1 WHERE z<100 AND a>5
**
** The code generated for this simplification gives the same result
** but only has to scan the data once.  And because indices might 
** exist on the table t1, a complete scan of the data might be
** avoided.
**
** Flattening is subject to the following constraints:
**
**  (**)  We no longer attempt to flatten aggregate subqueries. Was:
**        The subquery and the outer query cannot both be aggregates.
**
**  (**)  We no longer attempt to flatten aggregate subqueries. Was:
**        (2) If the subquery is an aggregate then
**        (2a) the outer query must not be a join and
**        (2b) the outer query must not use subqueries
**             other than the one FROM-clause subquery that is a candidate
**             for flattening.  (This is due to ticket [2f7170d73bf9abf80]
**             from 2015-02-09.)
**
**   (3)  If the subquery is the right operand of a LEFT JOIN then
**        (3a) the subquery may not be a join and
**        (3b) the FROM clause of the subquery may not contain a virtual
**             table and
**        (3c) the outer query may not be an aggregate.
**
**   (4)  The subquery can not be DISTINCT.
**
**  (**)  At one point restrictions (4) and (5) defined a subset of DISTINCT
**        sub-queries that were excluded from this optimization. Restriction 
**        (4) has since been expanded to exclude all DISTINCT subqueries.
**
**  (**)  We no longer attempt to flatten aggregate subqueries.  Was:
**        If the subquery is aggregate, the outer query may not be DISTINCT.
**
**   (7)  The subquery must have a FROM clause.  TODO:  For subqueries without
**        A FROM clause, consider adding a FROM clause with the special
**        table sqlite_once that consists of a single row containing a
**        single NULL.
**
**   (8)  If the subquery uses LIMIT then the outer query may not be a join.
**

**   (9)  If the subquery uses LIMIT then the outer query may not be aggregate.
**
**  (**)  Restriction (10) was removed from the code on 2005-02-05 but we
**        accidently carried the comment forward until 2014-09-15.  Original
**        constraint: "If the subquery is aggregate then the outer query 
**        may not use LIMIT."
**
**  (11)  The subquery and the outer query may not both have ORDER BY clauses.
**
**  (**)  Not implemented.  Subsumed into restriction (3).  Was previously
**        a separate restriction deriving from ticket #350.
**
**  (13)  The subquery and outer query may not both use LIMIT.
**
**  (14)  The subquery may not use OFFSET.
**
**  (15)  If the outer query is part of a compound select, then the
**        subquery may not use LIMIT.
**        (See ticket #2339 and ticket [02a8e81d44]).
**
**  (16)  If the outer query is aggregate, then the subquery may not
**        use ORDER BY.  (Ticket #2942)  This used to not matter
**        until we introduced the group_concat() function.  
**
**  (17)  If the subquery is a compound select, then
**        (17a) all compound operators must be a UNION ALL, and
**        (17b) no terms within the subquery compound may be aggregate
**              or DISTINT, and

**        (17c) every term within the subquery compound must have a FROM clause
**        (17d) the outer query may not be
**              (17d1) aggregate, or
**              (17d2) DISTINCT, or
**              (17d3) a join.
**
**        The parent and sub-query may contain WHERE clauses. Subject to
**        rules (11), (13) and (14), they may also contain ORDER BY,
**        LIMIT and OFFSET clauses.  The subquery cannot use any compound
**        operator other than UNION ALL because all the other compound
**        operators have an implied DISTINCT which is disallowed by
**        restriction (4).
**
**        Also, each component of the sub-query must return the same number
**        of result columns. This is actually a requirement for any compound
**        SELECT statement, but all the code here does is make sure that no
**        such (illegal) sub-query is flattened. The caller will detect the
**        syntax error and return a detailed message.
**
**  (18)  If the sub-query is a compound select, then all terms of the
**        ORDER BY clause of the parent must be simple references to 
**        columns of the sub-query.
**
**  (19)  If the subquery uses LIMIT then the outer query may not
**        have a WHERE clause.
**
**  (20)  If the sub-query is a compound select, then it must not use
**        an ORDER BY clause.  Ticket #3773.  We could relax this constraint
**        somewhat by saying that the terms of the ORDER BY clause must
**        appear as unmodified result columns in the outer query.  But we
**        have other optimizations in mind to deal with that case.
**
**  (21)  If the subquery uses LIMIT then the outer query may not be
**        DISTINCT.  (See ticket [752e1646fc]).
**
**  (22)  The subquery may not be a recursive CTE.
**
**  (23)  If the outer query is a recursive CTE, then the sub-query may not be
**        a compound query. This restriction is because transforming the
**        parent to a compound query confuses the code that handles
**        recursive queries in multiSelect().
**
**  (**)  We no longer attempt to flatten aggregate subqueries.  Was:
**        The subquery may not be an aggregate that uses the built-in min() or 
**        or max() functions.  (Without this restriction, a query like:
**        "SELECT x FROM (SELECT max(y), x FROM t1)" would not necessarily
**        return the value X for which Y was maximal.)
**
**
** In this routine, the "p" parameter is a pointer to the outer query.
** The subquery is p->pSrc->a[iFrom].  isAgg is true if the outer query
** uses aggregates.
**
** If flattening is not attempted, this routine is a no-op and returns 0.
** If flattening is attempted this routine returns 1.
**
** All of the expression analysis must occur on both the outer query and
** the subquery before this routine runs.
*/
static int flattenSubquery(
  Parse *pParse,       /* Parsing context */
  Select *p,           /* The parent or outer SELECT statement */
  int iFrom,           /* Index in p->pSrc->a[] of the inner subquery */
  int isAgg            /* True if outer SELECT uses aggregate functions */

){
  const char *zSavedAuthContext = pParse->zAuthContext;
  Select *pParent;    /* Current UNION ALL term of the other query */
  Select *pSub;       /* The inner query or "subquery" */
  Select *pSub1;      /* Pointer to the rightmost select in sub-query */
  SrcList *pSrc;      /* The FROM clause of the outer query */
  SrcList *pSubSrc;   /* The FROM clause of the subquery */
  int iParent;        /* VDBE cursor number of the pSub result set temp table */
  int iNewParent = -1;/* Replacement table for iParent */
  int isLeftJoin = 0; /* True if pSub is the right side of a LEFT JOIN */    
  int i;              /* Loop counter */
  Expr *pWhere;                    /* The WHERE clause */
  struct SrcList_item *pSubitem;   /* The subquery */
  sqlite3 *db = pParse->db;

  /* Check to see if flattening is permitted.  Return 0 if not.
  */
  assert( p!=0 );
  assert( p->pPrior==0 );
  if( OptimizationDisabled(db, SQLITE_QueryFlattener) ) return 0;
  pSrc = p->pSrc;
  assert( pSrc && iFrom>=0 && iFrom<pSrc->nSrc );
  pSubitem = &pSrc->a[iFrom];
  iParent = pSubitem->iCursor;
  pSub = pSubitem->pSelect;
  assert( pSub!=0 );











  pSubSrc = pSub->pSrc;
  assert( pSubSrc );
  /* Prior to version 3.1.2, when LIMIT and OFFSET had to be simple constants,
  ** not arbitrary expressions, we allowed some combining of LIMIT and OFFSET
  ** because they could be computed at compile-time.  But when LIMIT and OFFSET
  ** became arbitrary expressions, we were forced to add restrictions (13)
  ** and (14). */
  if( pSub->pLimit && p->pLimit ) return 0;              /* Restriction (13) */
  if( pSub->pOffset ) return 0;                          /* Restriction (14) */
  if( (p->selFlags & SF_Compound)!=0 && pSub->pLimit ){
    return 0;                                            /* Restriction (15) */
  }
  if( pSubSrc->nSrc==0 ) return 0;                       /* Restriction (7)  */
  if( pSub->selFlags & SF_Distinct ) return 0;           /* Restriction (4)  */
  if( pSub->pLimit && (pSrc->nSrc>1 || isAgg) ){
     return 0;         /* Restrictions (8)(9) */
  }



  if( p->pOrderBy && pSub->pOrderBy ){
     return 0;                                           /* Restriction (11) */
  }
  if( isAgg && pSub->pOrderBy ) return 0;                /* Restriction (16) */
  if( pSub->pLimit && p->pWhere ) return 0;              /* Restriction (19) */
  if( pSub->pLimit && (p->selFlags & SF_Distinct)!=0 ){
     return 0;         /* Restriction (21) */
  }


  if( pSub->selFlags & (SF_Recursive) ){
    return 0; /* Restrictions (22) */
  }
  if( (p->selFlags & SF_Recursive) && pSub->pPrior ){
    return 0; /* Restriction (23) */
  }

  /*
  ** If the subquery is the right operand of a LEFT JOIN, then the
  ** subquery may not be a join itself (3a). Example of why this is not
  ** allowed:
  **
  **         t1 LEFT OUTER JOIN (t2 JOIN t3)
  **
  ** If we flatten the above, we would get
  **
  **         (t1 LEFT OUTER JOIN t2) JOIN t3
  **
  ** which is not at all the same thing.
  **
  ** If the subquery is the right operand of a LEFT JOIN, then the outer
  ** query cannot be an aggregate. (3c)  This is an artifact of the way
  ** aggregates are processed - there is no mechanism to determine if
  ** the LEFT JOIN table should be all-NULL.
  **
  ** See also tickets #306, #350, and #3300.
  */
  if( (pSubitem->fg.jointype & JT_OUTER)!=0 ){
    isLeftJoin = 1;
    if( pSubSrc->nSrc>1 || isAgg || IsVirtual(pSubSrc->a[0].pTab) ){
      /*  (3a)             (3c)     (3b) */
      return 0;
    }
  }
#ifdef SQLITE_EXTRA_IFNULLROW
  else if( iFrom>0 && !isAgg ){
    /* Setting isLeftJoin to -1 causes OP_IfNullRow opcodes to be generated for
    ** every reference to any result column from subquery in a join, even
    ** though they are not necessary.  This will stress-test the OP_IfNullRow 
    ** opcode. */
    isLeftJoin = -1;
  }
#endif

  /* Restriction (17): If the sub-query is a compound SELECT, then it must
  ** use only the UNION ALL operator. And none of the simple select queries
  ** that make up the compound SELECT are allowed to be aggregate or distinct
  ** queries.
  */
  if( pSub->pPrior ){
    if( pSub->pOrderBy ){
      return 0;  /* Restriction (20) */
    }
    if( isAgg || (p->selFlags & SF_Distinct)!=0 || pSrc->nSrc!=1 ){
      return 0; /* (17d1), (17d2), or (17d3) */
    }
    for(pSub1=pSub; pSub1; pSub1=pSub1->pPrior){
      testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
      testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );
      assert( pSub->pSrc!=0 );
      assert( pSub->pEList->nExpr==pSub1->pEList->nExpr );
      if( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))!=0    /* (17b) */
       || (pSub1->pPrior && pSub1->op!=TK_ALL)                 /* (17a) */
       || pSub1->pSrc->nSrc<1                                  /* (17c) */
      ){
        return 0;
      }
      testcase( pSub1->pSrc->nSrc>1 );
    }

    /* Restriction (18). */
    if( p->pOrderBy ){
      int ii;
      for(ii=0; ii<p->pOrderBy->nExpr; ii++){
        if( p->pOrderBy->a[ii].u.x.iOrderByCol==0 ) return 0;
      }
    }
  }

      pParent->pOrderBy = pOrderBy;
      pSub->pOrderBy = 0;
    }
    pWhere = sqlite3ExprDup(db, pSub->pWhere, 0);
    if( isLeftJoin>0 ){
      setJoinExpr(pWhere, iNewParent);
    }










    pParent->pWhere = sqlite3ExprAnd(db, pWhere, pParent->pWhere);

    if( db->mallocFailed==0 ){
      SubstContext x;
      x.pParse = pParse;
      x.iTable = iParent;
      x.iNewTable = iNewParent;
      x.isLeftJoin = isLeftJoin;
      x.pEList = pSub->pEList;

**     WHERE x=5 AND y=10;
**
** The hope is that the terms added to the inner query will make it more
** efficient.
**
** Do not attempt this optimization if:
**
**   (1) (** This restriction was removed on 2017-09-29.  We used to
**           disallow this optimization for aggregate subqueries, but now
**           it is allowed by putting the extra terms on the HAVING clause.
**           The added HAVING clause is pointless if the subquery lacks
**           a GROUP BY clause.  But such a HAVING clause is also harmless
**           so there does not appear to be any reason to add extra logic
**           to suppress it. **)
**
**   (2) The inner query is the recursive part of a common table expression.
**
**   (3) The inner query has a LIMIT clause (since the changes to the WHERE
**       close would change the meaning of the LIMIT).
**
**   (4) The inner query is the right operand of a LEFT JOIN.  (The caller

  Parse *pParse,        /* Parse context (for malloc() and error reporting) */
  Select *pSubq,        /* The subquery whose WHERE clause is to be augmented */
  Expr *pWhere,         /* The WHERE clause of the outer query */
  int iCursor           /* Cursor number of the subquery */
){
  Expr *pNew;
  int nChng = 0;

  if( pWhere==0 ) return 0;
  if( pSubq->selFlags & SF_Recursive ) return 0;  /* restriction (2) */

#ifdef SQLITE_DEBUG
  /* Only the first term of a compound can have a WITH clause.  But make
  ** sure no other terms are marked SF_Recursive in case something changes
  ** in the future.
  */
  {
    Select *pX;  
    for(pX=pSubq; pX; pX=pX->pPrior){
      assert( (pX->selFlags & (SF_Recursive))==0 );




    }
  }
#endif

  if( pSubq->pLimit!=0 ){
    return 0; /* restriction (3) */
  }
  while( pWhere->op==TK_AND ){
    nChng += pushDownWhereTerms(pParse, pSubq, pWhere->pRight, iCursor);
    pWhere = pWhere->pLeft;
  }
  if( ExprHasProperty(pWhere,EP_FromJoin) ) return 0; /* restriction (5) */
  if( sqlite3ExprIsTableConstant(pWhere, iCursor) ){
    nChng++;
    while( pSubq ){
      SubstContext x;
      pNew = sqlite3ExprDup(pParse->db, pWhere, 0);
      x.pParse = pParse;
      x.iTable = iCursor;
      x.iNewTable = iCursor;
      x.isLeftJoin = 0;
      x.pEList = pSubq->pEList;
      pNew = substExpr(&x, pNew);
      if( pSubq->selFlags & SF_Aggregate ){
        pSubq->pHaving = sqlite3ExprAnd(pParse->db, pSubq->pHaving, pNew);
      }else{
        pSubq->pWhere = sqlite3ExprAnd(pParse->db, pSubq->pWhere, pNew);
      }
      pSubq = pSubq->pPrior;
    }
  }
  return nChng;
}
#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */

    /* Only one recursive reference is permitted. */ 
    if( pTab->nTabRef>2 ){
      sqlite3ErrorMsg(
          pParse, "multiple references to recursive table: %s", pCte->zName
      );
      return SQLITE_ERROR;
    }
    assert( pTab->nTabRef==1 || 
            ((pSel->selFlags&SF_Recursive) && pTab->nTabRef==2 ));

    pCte->zCteErr = "circular reference: %s";
    pSavedWith = pParse->pWith;
    pParse->pWith = pWith;
    if( bMayRecursive ){
      Select *pPrior = pSel->pPrior;
      assert( pPrior->pWith==0 );

      /* A sub-query in the FROM clause of a SELECT */
      assert( pSel!=0 );
      assert( pFrom->pTab==0 );
      if( sqlite3WalkSelect(pWalker, pSel) ) return WRC_Abort;
      pFrom->pTab = pTab = sqlite3DbMallocZero(db, sizeof(Table));
      if( pTab==0 ) return WRC_Abort;
      pTab->nTabRef = 1;
      if( pFrom->zAlias ){
        pTab->zName = sqlite3DbStrDup(db, pFrom->zAlias);
      }else{
        pTab->zName = sqlite3MPrintf(db, "subquery_%p", (void*)pTab);
      }
      while( pSel->pPrior ){ pSel = pSel->pPrior; }
      sqlite3ColumnsFromExprList(pParse, pSel->pEList,&pTab->nCol,&pTab->aCol);
      pTab->iPKey = -1;
      pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
      pTab->tabFlags |= TF_Ephemeral;
#endif
    }else{

** Return TRUE if the optimization is undertaken.
*/
static int countOfViewOptimization(Parse *pParse, Select *p){
  Select *pSub, *pPrior;
  Expr *pExpr;
  Expr *pCount;
  sqlite3 *db;
  if( (p->selFlags & SF_Aggregate)==0 ) return 0;   /* This is an aggregate */
  if( p->pEList->nExpr!=1 ) return 0;               /* Single result column */
  pExpr = p->pEList->a[0].pExpr;
  if( pExpr->op!=TK_AGG_FUNCTION ) return 0;        /* Result is an aggregate */
  if( sqlite3_stricmp(pExpr->u.zToken,"count") ) return 0;  /* Is count() */
  if( pExpr->x.pList!=0 ) return 0;                 /* Must be count(*) */
  if( p->pSrc->nSrc!=1 ) return 0;                  /* One table in FROM  */
  pSub = p->pSrc->a[0].pSelect;
  if( pSub==0 ) return 0;                           /* The FROM is a subquery */
  if( pSub->pPrior==0 ) return 0;                   /* Must be a compound ry */
  do{
    if( pSub->op!=TK_ALL && pSub->pPrior ) return 0;  /* Must be UNION ALL */
    if( pSub->pWhere ) return 0;                      /* No WHERE clause */
    if( pSub->selFlags & SF_Aggregate ) return 0;     /* Not an aggregate */
    pSub = pSub->pPrior;                              /* Repeat over compound */
  }while( pSub );

  /* If we reach this point then it is OK to perform the transformation */

  db = pParse->db;
  pCount = pExpr;
  pExpr = 0;
  pSub = p->pSrc->a[0].pSelect;
  p->pSrc->a[0].pSelect = 0;
  sqlite3SrcListDelete(db, p->pSrc);

  /* Try to flatten subqueries in the FROM clause up into the main query
  */
#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
  for(i=0; !p->pPrior && i<pTabList->nSrc; i++){
    struct SrcList_item *pItem = &pTabList->a[i];
    Select *pSub = pItem->pSelect;

    Table *pTab = pItem->pTab;
    if( pSub==0 ) continue;

    /* Catch mismatch in the declared columns of a view and the number of
    ** columns in the SELECT on the RHS */
    if( pTab->nCol!=pSub->pEList->nExpr ){
      sqlite3ErrorMsg(pParse, "expected %d columns for '%s' but got %d",
                      pTab->nCol, pTab->zName, pSub->pEList->nExpr);
      goto select_end;
    }

    /* Do not try to flatten an aggregate subquery.
    **
    ** Flattening an aggregate subquery is only possible if the outer query
    ** is not a join.  But if the outer query is not a join, then the subquery
    ** will be implemented as a co-routine and there is no advantage to
    ** flattening in that case.
    */
    if( (pSub->selFlags & SF_Aggregate)!=0 ) continue;
    assert( pSub->pGroupBy==0 );

    /* If the subquery contains an ORDER BY clause and if
    ** it will be implemented as a co-routine, then do not flatten.  This
    ** restriction allows SQL constructs like this:
    **
    **  SELECT expensive_function(x)
    **    FROM (SELECT x FROM tab ORDER BY y LIMIT 10);
    **
    ** The expensive_function() is only computed on the 10 rows that
    ** are output, rather than every row of the table.
    */
    if( pSub->pOrderBy!=0
     && i==0
     && (pTabList->nSrc==1
         || (pTabList->a[1].fg.jointype&(JT_LEFT|JT_CROSS))!=0)
    ){
      continue;
    }

    if( flattenSubquery(pParse, p, i, isAgg) ){
      /* This subquery can be absorbed into its parent. */




      i = -1;
    }
    pTabList = p->pSrc;
    if( db->mallocFailed ) goto select_end;
    if( !IgnorableOrderby(pDest) ){
      sSort.pOrderBy = p->pOrderBy;
    }

  ** (1) Authorized unreferenced tables
  ** (2) Generate code for all sub-queries
  */
  for(i=0; i<pTabList->nSrc; i++){
    struct SrcList_item *pItem = &pTabList->a[i];
    SelectDest dest;
    Select *pSub;
#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
    const char *zSavedAuthContext;
#endif

    /* Issue SQLITE_READ authorizations with a fake column name for any
    ** tables that are referenced but from which no values are extracted.
    ** Examples of where these kinds of null SQLITE_READ authorizations
    ** would occur:
    **
    **     SELECT count(*) FROM t1;   -- SQLITE_READ t1.""
    **     SELECT t1.* FROM t1, t2;   -- SQLITE_READ t2.""
    **
    ** The fake column name is an empty string.  It is possible for a table to
    ** have a column named by the empty string, in which case there is no way to
    ** distinguish between an unreferenced table and an actual reference to the
    ** "" column. The original design was for the fake column name to be a NULL,
    ** which would be unambiguous.  But legacy authorization callbacks might
    ** assume the column name is non-NULL and segfault.  The use of an empty
    ** string for the fake column name seems safer.
    */
    if( pItem->colUsed==0 ){
      sqlite3AuthCheck(pParse, SQLITE_READ, pItem->zName, "", pItem->zDatabase);
    }

#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
    /* Generate code for all sub-queries in the FROM clause

#if SELECTTRACE_ENABLED
      if( sqlite3SelectTrace & 0x100 ){
        SELECTTRACE(0x100,pParse,p,("After WHERE-clause push-down:\n"));
        sqlite3TreeViewSelect(0, p, 0);
      }
#endif
    }

    zSavedAuthContext = pParse->zAuthContext;
    pParse->zAuthContext = pItem->zName;

    /* Generate code to implement the subquery
    **
    ** The subquery is implemented as a co-routine if the subquery is
    ** guaranteed to be the outer loop (so that it does not need to be
    ** computed more than once)





    **
    ** TODO: Are there other reasons beside (1) to use a co-routine
    ** implementation?
    */
    if( i==0
     && (pTabList->nSrc==1
            || (pTabList->a[1].fg.jointype&(JT_LEFT|JT_CROSS))!=0)  /* (1) */


    ){
      /* Implement a co-routine that will return a single row of the result
      ** set on each invocation.
      */
      int addrTop = sqlite3VdbeCurrentAddr(v)+1;
     
      pItem->regReturn = ++pParse->nMem;
      sqlite3VdbeAddOp3(v, OP_InitCoroutine, pItem->regReturn, 0, addrTop);
      VdbeComment((v, "%s", pItem->pTab->zName));
      pItem->addrFillSub = addrTop;
      sqlite3SelectDestInit(&dest, SRT_Coroutine, pItem->regReturn);
      explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId);
      sqlite3Select(pParse, pSub, &dest);

      retAddr = sqlite3VdbeAddOp1(v, OP_Return, pItem->regReturn);
      VdbeComment((v, "end %s", pItem->pTab->zName));
      sqlite3VdbeChangeP1(v, topAddr, retAddr);
      sqlite3ClearTempRegCache(pParse);
    }
    if( db->mallocFailed ) goto select_end;
    pParse->nHeight -= sqlite3SelectExprHeight(p);
    pParse->zAuthContext = zSavedAuthContext;
#endif
  }

  /* Various elements of the SELECT copied into local variables for
  ** convenience */
  pEList = p->pEList;
  pWhere = p->pWhere;

** for the LHS anyplace else in the WHERE clause where the LHS column occurs.
** This is an optimization.  No harm comes from returning 0.  But if 1 is
** returned when it should not be, then incorrect answers might result.
*/
static int termIsEquivalence(Parse *pParse, Expr *pExpr){
  char aff1, aff2;
  CollSeq *pColl;

  if( !OptimizationEnabled(pParse->db, SQLITE_Transitive) ) return 0;
  if( pExpr->op!=TK_EQ && pExpr->op!=TK_IS ) return 0;
  if( ExprHasProperty(pExpr, EP_FromJoin) ) return 0;
  aff1 = sqlite3ExprAffinity(pExpr->pLeft);
  aff2 = sqlite3ExprAffinity(pExpr->pRight);
  if( aff1!=aff2
   && (!sqlite3IsNumericAffinity(aff1) || !sqlite3IsNumericAffinity(aff2))
  ){
    return 0;
  }
  pColl = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft, pExpr->pRight);
  if( pColl==0 || sqlite3StrICmp(pColl->zName, "BINARY")==0 ) return 1;
  return sqlite3ExprCollSeqMatch(pParse, pExpr->pLeft, pExpr->pRight);




}

/*
** Recursively walk the expressions of a SELECT statement and generate
** a bitmask indicating which tables are used in that expression
** tree.
*/

  for(i=0; i<pList->nExpr; i++){
    Expr *p = sqlite3ExprSkipCollate(pList->a[i].pExpr);
    if( p->op==TK_COLUMN
     && p->iColumn==pIdx->aiColumn[iCol]
     && p->iTable==iBase
    ){
      CollSeq *pColl = sqlite3ExprNNCollSeq(pParse, pList->a[i].pExpr);
      if( 0==sqlite3StrICmp(pColl->zName, zColl) ){
        return i;
      }
    }
  }

  return -1;
}

      if( pExpr->iColumn<0 ) return 1;
      for(jj=0; jj<pIndex->nKeyCol; jj++){
        if( pExpr->iColumn==pIndex->aiColumn[jj] ) return 1;
      }
    }else if( (aColExpr = pIndex->aColExpr)!=0 ){
      for(jj=0; jj<pIndex->nKeyCol; jj++){
        if( pIndex->aiColumn[jj]!=XN_EXPR ) continue;
        if( sqlite3ExprCompareSkip(pExpr,aColExpr->a[jj].pExpr,iCursor)==0 ){
          return 1;
        }
      }
    }
  }
  return 0;
}

        ** optimization, and then only if they are actually used
        ** by the query plan */
        assert( wctrlFlags & WHERE_ORDERBY_LIMIT );
        for(j=0; j<pLoop->nLTerm && pTerm!=pLoop->aLTerm[j]; j++){}
        if( j>=pLoop->nLTerm ) continue;
      }
      if( (pTerm->eOperator&(WO_EQ|WO_IS))!=0 && pOBExpr->iColumn>=0 ){

        if( sqlite3ExprCollSeqMatch(pWInfo->pParse, 


                  pOrderBy->a[i].pExpr, pTerm->pExpr)==0 ){


          continue;
        }
        testcase( pTerm->pExpr->op==TK_IS );
      }
      obSat |= MASKBIT(i);
    }

    if( (pLoop->wsFlags & WHERE_ONEROW)==0 ){
      if( pLoop->wsFlags & WHERE_IPK ){

        /* Get the column number in the table (iColumn) and sort order
        ** (revIdx) for the j-th column of the index.
        */
        if( pIndex ){
          iColumn = pIndex->aiColumn[j];
          revIdx = pIndex->aSortOrder[j];
          if( iColumn==pIndex->pTable->iPKey ) iColumn = XN_ROWID;
        }else{
          iColumn = XN_ROWID;
          revIdx = 0;
        }

        /* An unconstrained column that might be NULL means that this
        ** WhereLoop is not well-ordered

        isMatch = 0;
        for(i=0; bOnce && i<nOrderBy; i++){
          if( MASKBIT(i) & obSat ) continue;
          pOBExpr = sqlite3ExprSkipCollate(pOrderBy->a[i].pExpr);
          testcase( wctrlFlags & WHERE_GROUPBY );
          testcase( wctrlFlags & WHERE_DISTINCTBY );
          if( (wctrlFlags & (WHERE_GROUPBY|WHERE_DISTINCTBY))==0 ) bOnce = 0;
          if( iColumn>=XN_ROWID ){
            if( pOBExpr->op!=TK_COLUMN ) continue;
            if( pOBExpr->iTable!=iCur ) continue;
            if( pOBExpr->iColumn!=iColumn ) continue;
          }else{
            Expr *pIdxExpr = pIndex->aColExpr->a[j].pExpr;
            if( sqlite3ExprCompareSkip(pOBExpr, pIdxExpr, iCur) ){

              continue;
            }
          }
          if( iColumn!=XN_ROWID ){
            pColl = sqlite3ExprNNCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);

            if( sqlite3StrICmp(pColl->zName, pIndex->azColl[j])!=0 ) continue;
          }
          pLoop->u.btree.nIdxCol = j+1;
          isMatch = 1;
          break;
        }
        if( isMatch && (wctrlFlags & WHERE_GROUPBY)==0 ){

**    YYERRORSYMBOL      is the code number of the error symbol.  If not
**                       defined, then do no error processing.
**    YYNSTATE           the combined number of states.
**    YYNRULE            the number of rules in the grammar
**    YY_MAX_SHIFT       Maximum value for shift actions
**    YY_MIN_SHIFTREDUCE Minimum value for shift-reduce actions
**    YY_MAX_SHIFTREDUCE Maximum value for shift-reduce actions
**    YY_MIN_REDUCE      Minimum value for reduce actions
**    YY_MAX_REDUCE      Maximum value for reduce actions
**    YY_ERROR_ACTION    The yy_action[] code for syntax error
**    YY_ACCEPT_ACTION   The yy_action[] code for accept
**    YY_NO_ACTION       The yy_action[] code for no-op
*/
#ifndef INTERFACE
# define INTERFACE 1
#endif

**    fts5YYERRORSYMBOL      is the code number of the error symbol.  If not
**                       defined, then do no error processing.
**    fts5YYNSTATE           the combined number of states.
**    fts5YYNRULE            the number of rules in the grammar
**    fts5YY_MAX_SHIFT       Maximum value for shift actions
**    fts5YY_MIN_SHIFTREDUCE Minimum value for shift-reduce actions
**    fts5YY_MAX_SHIFTREDUCE Maximum value for shift-reduce actions
**    fts5YY_MIN_REDUCE      Minimum value for reduce actions
**    fts5YY_MAX_REDUCE      Maximum value for reduce actions
**    fts5YY_ERROR_ACTION    The fts5yy_action[] code for syntax error
**    fts5YY_ACCEPT_ACTION   The fts5yy_action[] code for accept
**    fts5YY_NO_ACTION       The fts5yy_action[] code for no-op
*/
#ifndef INTERFACE
# define INTERFACE 1
#endif

static void fts5SourceIdFunc(
  sqlite3_context *pCtx,          /* Function call context */
  int nArg,                       /* Number of args */
  sqlite3_value **apUnused        /* Function arguments */
){
  assert( nArg==0 );
  UNUSED_PARAM2(nArg, apUnused);
  sqlite3_result_text(pCtx, "fts5: 2017-09-29 16:07:56 0840f9f824c16212ce3fd6c859e501176eb0a58924ea1728a54d5bdfd0c25c86", -1, SQLITE_TRANSIENT);
}

static int fts5Init(sqlite3 *db){
  static const sqlite3_module fts5Mod = {
    /* iVersion      */ 2,
    /* xCreate       */ fts5CreateMethod,
    /* xConnect      */ fts5ConnectMethod,

#endif
  return rc;
}
#endif /* SQLITE_CORE */
#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_STMTVTAB) */

/************** End of stmt.c ************************************************/
#if __LINE__!=204971
#undef SQLITE_SOURCE_ID
#define SQLITE_SOURCE_ID      "2017-10-02 02:52:54 c9104b59c7ed360291f7f6fc8caae938e9840c77620d598e4096f78183bfalt2"
#endif
/* Return the source-id for this library */
SQLITE_API const char *sqlite3_sourceid(void){ return SQLITE_SOURCE_ID; }
/************************** End of sqlite3.c ******************************/

**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.21.0"
#define SQLITE_VERSION_NUMBER 3021000
#define SQLITE_SOURCE_ID      "2017-10-02 02:52:54 c9104b59c7ed360291f7f6fc8caae938e9840c77620d598e4096f78183bf807a"

/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros