SQLite

      sqlite3AutoincrementBegin(pParse);

      /* Code constant expressions that where factored out of inner loops */
      if( pParse->pConstExpr ){
        ExprList *pEL = pParse->pConstExpr;
        pParse->okConstFactor = 0;
        for(i=0; i<pEL->nExpr; i++){
          int iReg = pEL->a[i].u.iConstExprReg;
          if( iReg>0 ){
            sqlite3ExprCode(pParse, pEL->a[i].pExpr, iReg);
          }
        }
      }

      /* Finally, jump back to the beginning of the executable code. */
      sqlite3VdbeGoto(v, 1);
    }
  }

    op = pExpr->op;
  }
  switch( op ){
    case TK_AGG_COLUMN: {
      AggInfo *pAggInfo = pExpr->pAggInfo;
      struct AggInfo_col *pCol;
      assert( pAggInfo!=0 );
      assert( AggInfoValid(pAggInfo) );
      assert( pExpr->iAgg>=0 && pExpr->iAgg<pAggInfo->nColumn );
      pCol = &pAggInfo->aCol[pExpr->iAgg];
      if( !pAggInfo->directMode ){
        assert( pCol->iMem>0 );
        return pCol->iMem;
      }else if( pAggInfo->useSortingIdx ){
        Table *pTab = pCol->pTab;

      if( pInfo==0
       || NEVER(pExpr->iAgg<0)
       || NEVER(pExpr->iAgg>=pInfo->nFunc)
      ){
        assert( !ExprHasProperty(pExpr, EP_IntValue) );
        sqlite3ErrorMsg(pParse, "misuse of aggregate: %s()", pExpr->u.zToken);
      }else{
        assert( AggInfoValid(pInfo) );
        return pInfo->aFunc[pExpr->iAgg].iMem;
      }
      break;
    }
    case TK_FUNCTION: {
      ExprList *pFarg;       /* List of function arguments */
      int nFarg;             /* Number of function arguments */

  int nOther;      /* Number of references to columns in other FROM clauses */
};

/*
** Count the number of references to columns.
*/
static int exprSrcCount(Walker *pWalker, Expr *pExpr){






  if( pExpr->op==TK_COLUMN || NEVER(pExpr->op==TK_AGG_COLUMN) ){
    int i;
    struct SrcCount *p = pWalker->u.pSrcCount;
    SrcList *pSrc = p->pSrc;
    int nSrc = pSrc ? pSrc->nSrc : 0;
    for(i=0; i<nSrc; i++){
      if( pExpr->iTable==pSrc->a[i].iCursor ) break;
    }

** Changing the pending byte during operation will result in undefined
** and incorrect behavior.
*/
#ifndef SQLITE_OMIT_WSD
int sqlite3PendingByte = 0x40000000;
#endif

/*
** Flags for select tracing and the ".selecttrace" macro of the CLI
*/
/**/ u32 sqlite3SelectTrace = 0;

#include "opcodes.h"
/*
** Properties of opcodes.  The OPFLG_INITIALIZER macro is
** created by mkopcodeh.awk during compilation.  Data is obtained
** from the comments following the "case OP_xxxx:" statements in
** the vdbe.c file.  
*/

            pNC2 = pNC2->pNext;
          }
          assert( pDef!=0 || IN_RENAME_OBJECT );
          if( pNC2 && pDef ){
            assert( SQLITE_FUNC_MINMAX==NC_MinMaxAgg );
            testcase( (pDef->funcFlags & SQLITE_FUNC_MINMAX)!=0 );
            pNC2->ncFlags |= NC_HasAgg | (pDef->funcFlags & SQLITE_FUNC_MINMAX);

          }
        }
        pNC->ncFlags |= savedAllowFlags;
      }
      /* FIX ME:  Compute pExpr->affinity based on the expected return
      ** type of the function 
      */

  Expr *pE           /* The specific ORDER BY term */
){
  int i;             /* Loop counter */
  ExprList *pEList;  /* The columns of the result set */
  NameContext nc;    /* Name context for resolving pE */
  sqlite3 *db;       /* Database connection */
  int rc;            /* Return code from subprocedures */


  assert( sqlite3ExprIsInteger(pE, &i)==0 );
  pEList = pSelect->pEList;

  /* Resolve all names in the ORDER BY term expression
  */
  memset(&nc, 0, sizeof(nc));
  nc.pParse = pParse;
  nc.pSrcList = pSelect->pSrc;
  nc.uNC.pEList = pEList;
  nc.ncFlags = NC_AllowAgg|NC_UEList;
  nc.nErr = 0;
  db = pParse->db;
  assert( pParse->nErr==0 );
  rc = sqlite3ResolveExprNames(&nc, pE);

  /* Discard any error. The only error that can occur in the above call
  ** that we care about is SQLITE_NOMEM, the occurence of which is recorded in
  ** db->mallocFailed.  */
  assert( rc!=SQLITE_NOMEM || db->mallocFailed );
  if( IN_RENAME_OBJECT==0 ){
    sqlite3DbFree(db, pParse->zErrMsg);
    pParse->zErrMsg = 0;
    pParse->nErr = 0;
  }
  if( rc ) return 0;

  /* Try to match the ORDER BY expression against an expression
  ** in the result set.  Return an 1-based index of the matching
  ** result-set entry.
  */
  for(i=0; i<pEList->nExpr; i++){

          ** case. This allows the code in alter.c to modify column
          ** refererences within the ORDER BY expression as required.  */
          if( IN_RENAME_OBJECT ){
            pDup = pE;
          }else{
            pDup = sqlite3ExprDup(db, pE, 0);
          }
          if( !db->mallocFailed && !pParse->nErr ){
            assert(pDup);
            iCol = resolveOrderByTermToExprList(pParse, pSelect, pDup);
          }
          if( !IN_RENAME_OBJECT ){
            sqlite3ExprDelete(db, pDup);
          }
        }

      for(pWin=p->pWinDefn; pWin; pWin=pWin->pNextWin){
        if( sqlite3ResolveExprListNames(&sNC, pWin->pOrderBy)
         || sqlite3ResolveExprListNames(&sNC, pWin->pPartition)
        ){
          return WRC_Abort;
        }
      }
    }else if( p->pWin && ALWAYS( (p->selFlags & SF_WinRewrite)==0 ) ){
#if SELECTTRACE_ENABLED
      if( (sqlite3SelectTrace & 0x108)!=0 ){
        SELECTTRACE(0x104,pParse,p,
              ("(%u/%p) before window rewrite:\n",p->selId,p));
        sqlite3TreeViewSelect(0, p, 0);
      }
#endif
      sqlite3WindowRewrite(pParse, p);
#if SELECTTRACE_ENABLED
      if( (sqlite3SelectTrace & 0x108)!=0 ){
        SELECTTRACE(0x104,pParse,p, 
              ("(%u/%p) after window rewrite:\n",p->selId,p));
        sqlite3TreeViewSelect(0, p, 0);
      }
#endif
    }
#endif

    /* If this is part of a compound SELECT, check that it has the right
    ** number of expressions in the select list. */
    if( p->pNext && p->pEList->nExpr!=p->pNext->pEList->nExpr ){
      sqlite3SelectWrongNumTermsError(pParse, p->pNext);

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
*/
#include "sqliteInt.h"















/*
** An instance of the following object is used to record information about
** how to process the DISTINCT keyword, to simplify passing that information
** into the selectInnerLoop() routine.
*/
typedef struct DistinctCtx DistinctCtx;

    pAllocated = 0;
  }else{
    assert( pNew->pSrc!=0 || pParse->nErr>0 );
  }
  return pAllocated;
}


/*
** Delete the given Select structure and all of its substructures.
*/
void sqlite3SelectDelete(sqlite3 *db, Select *p){
  if( OK_IF_ALWAYS_TRUE(p) ) clearSelect(db, p, 1);
}

/*
** Make arrangements to delete a subquery when the Parse object is
** destroyed.
**
** This works by adding the subquery to the Parse.pConstExpr list, but
** with a register number of zero.  The pConstExpr list is destroyed
** when the Parse object is destroyed.  And the zero register means
** that the expression is not coded.
*/
void sqlite3SelectDeferredDelete(Parse *pParse, Select *p){
  Expr *pNew = sqlite3PExpr(pParse, TK_SELECT, 0, 0);
  if( pNew==0 ){
    clearSelect(pParse->db, p, 1);
  }else{
    sqlite3PExprAddSelect(pParse, pNew, p);
    pParse->pConstExpr =
      sqlite3ExprListAppend(pParse, pParse->pConstExpr, pNew);
    testcase( pParse->pConstExpr==0 ); /* Only true following OOM */
#ifdef SQLITE_DEBUG
    if( pParse->pConstExpr ){
      ExprList *p = pParse->pConstExpr;
      struct ExprList_item *pItem = &p->a[p->nExpr-1];
      assert( pItem->reusable==0 );
      assert( pItem->u.iConstExprReg==0 );
    }
#endif
  }
}

/*
** Delete all the substructure for p, but keep p allocated.  Redefine
** p to be a single SELECT where every column of the result set has a
** value of NULL.
*/
void sqlite3SelectReset(Parse *pParse, Select *p){

      recomputeColumnsUsed(pParent, &pSrc->a[i+iFrom]);
    }
  }

  /* Finially, delete what is left of the subquery and return
  ** success.
  */
  sqlite3SelectDeferredDelete(pParse, pSub1);

#if SELECTTRACE_ENABLED
  if( sqlite3SelectTrace & 0x100 ){
    SELECTTRACE(0x100,pParse,p,("After flattening:\n"));
    sqlite3TreeViewSelect(0, p, 0);
  }
#endif

  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 */
  int isLeftJoin        /* True if pSubq is the right term of a LEFT JOIN */
){
  Expr *pNew;
  int nChng = 0;
  Select *pSel;
  if( pWhere==0 ) return 0;
  if( pSubq->selFlags & SF_Recursive ) return 0;  /* restriction (2) */

#ifndef SQLITE_OMIT_WINDOWFUNC
  for(pSel=pSubq; pSel; pSel=pSel->pPrior){
    if( pSel->pWin ) return 0;    /* restriction (6) */
  }
#endif

#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.
  */

void sqlite3SelectPrep(
  Parse *pParse,         /* The parser context */
  Select *p,             /* The SELECT statement being coded. */
  NameContext *pOuterNC  /* Name context for container */
){
  assert( p!=0 || pParse->db->mallocFailed );
  if( pParse->db->mallocFailed ) return;

  sqlite3SelectExpand(pParse, p);
  if( pParse->nErr || pParse->db->mallocFailed ) return;
  sqlite3ResolveSelectNames(pParse, p, pOuterNC);
  if( pParse->nErr || pParse->db->mallocFailed ) return;
  sqlite3SelectAddTypeInfo(pParse, p);
}

  db = pParse->db;
  v = sqlite3GetVdbe(pParse);
  if( p==0 || db->mallocFailed || pParse->nErr ){
    return 1;
  }
  if( sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0) ) return 1;
  memset(&sAggInfo, 0, sizeof(sAggInfo));
#ifdef SQLITE_DEBUG
  sAggInfo.iAggMagic = SQLITE_AGGMAGIC_VALID;
#endif
#if SELECTTRACE_ENABLED
  SELECTTRACE(1,pParse,p, ("begin processing:\n", pParse->addrExplain));
  if( sqlite3SelectTrace & 0x100 ){
    sqlite3TreeViewSelect(0, p, 0);
  }
#endif

           pDest->eDest==SRT_DistQueue || pDest->eDest==SRT_Fifo);
    /* If ORDER BY makes no difference in the output then neither does
    ** DISTINCT so it can be removed too. */
    sqlite3ExprListDelete(db, p->pOrderBy);
    p->pOrderBy = 0;
    p->selFlags &= ~SF_Distinct;
  }
  if( (p->selFlags & SF_HasTypeInfo)==0 ){
    sqlite3SelectPrep(pParse, p, 0);
    if( pParse->nErr || db->mallocFailed ){
      goto select_end;
    }
    assert( p->pEList!=0 );
#if SELECTTRACE_ENABLED
    if( sqlite3SelectTrace & 0x104 ){
      SELECTTRACE(0x104,pParse,p, ("after name resolution:\n"));
      sqlite3TreeViewSelect(0, p, 0);
    }
#endif
  }

  if( pDest->eDest==SRT_Output ){
    generateColumnNames(pParse, p);
  }














  pTabList = p->pSrc;
  isAgg = (p->selFlags & SF_Aggregate)!=0;
  memset(&sSort, 0, sizeof(sSort));
  sSort.pOrderBy = p->pOrderBy;

  /* Try to various optimizations (flattening subqueries, and strength
  ** reduction of join operators) in the FROM clause up into the main query

  ** used for both the ORDER BY and DISTINCT processing. As originally 
  ** written the query must use a temp-table for at least one of the ORDER 
  ** BY and DISTINCT, and an index or separate temp-table for the other.
  */
  if( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct 
   && sqlite3ExprListCompare(sSort.pOrderBy, pEList, -1)==0
#ifndef SQLITE_OMIT_WINDOWFUNC
   && ALWAYS(p->pWin==0)
#endif
  ){
    p->selFlags &= ~SF_Distinct;
    pGroupBy = p->pGroupBy = sqlite3ExprListDup(db, pEList, 0);
    p->selFlags |= SF_Aggregate;
    /* Notice that even thought SF_Distinct has been cleared from p->selFlags,
    ** the sDistinct.isTnct is still set.  Hence, isTnct represents the

                       (char*)sqlite3KeyInfoFromExprList(pParse, p->pEList,0,0),
                       P4_KEYINFO);
    sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
    sDistinct.eTnctType = WHERE_DISTINCT_UNORDERED;
  }else{
    sDistinct.eTnctType = WHERE_DISTINCT_NOOP;
  }

#ifndef SQLITE_OMIT_WINDOWFUNC
  /* By the time the Select object reaches this point, it will have been
  ** transformed (mostly by sqlite3WindowRewrite()) so it cannot be both
  ** a single-row aggregate and contain a window function.  In other words,
  ** if the Select has a window function then it may not have either an
  ** aggregate function or a GROUP BY clause. */
  assert( (!isAgg && pGroupBy==0) || p->pWin==0 );
#endif

  if( !isAgg && pGroupBy==0 ){
    /* No aggregate functions and no GROUP BY clause */
    u16 wctrlFlags = (sDistinct.isTnct ? WHERE_WANT_DISTINCT : 0)
                   | (p->selFlags & SF_FixedLimit);
#ifndef SQLITE_OMIT_WINDOWFUNC
    Window *pWin = p->pWin;      /* Master window object (or NULL) */
    if( pWin ){
      sqlite3WindowCodeInit(pParse, p);
    }
#endif
    assert( WHERE_USE_LIMIT==SF_FixedLimit );


    /* Begin the database scan. */
    SELECTTRACE(1,pParse,p,("WhereBegin-A\n"));
    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, sSort.pOrderBy,
                               p->pEList, wctrlFlags, p->nSelectRow);
    if( pWInfo==0 ) goto select_end;
    if( sqlite3WhereOutputRowCount(pWInfo) < p->nSelectRow ){
      p->nSelectRow = sqlite3WhereOutputRowCount(pWInfo);
    }
    if( sDistinct.isTnct && sqlite3WhereIsDistinct(pWInfo) ){

      /* Begin a loop that will extract all source rows in GROUP BY order.
      ** This might involve two separate loops with an OP_Sort in between, or
      ** it might be a single loop that uses an index to extract information
      ** in the right order to begin with.
      */
      sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset);
      SELECTTRACE(1,pParse,p,("WhereBegin-B\n"));
      pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pGroupBy, 0,
          WHERE_GROUPBY | (orderByGrp ? WHERE_SORTBYGROUP : 0), 0
      );
      if( pWInfo==0 ) goto select_end;
      if( sqlite3WhereIsOrdered(pWInfo)==pGroupBy->nExpr ){
        /* The optimizer is able to deliver rows in group by order so
        ** we do not have to sort.  The OP_OpenEphemeral table will be

        ** minMaxFlag will have been previously set to either
        ** WHERE_ORDERBY_MIN or WHERE_ORDERBY_MAX and pMinMaxOrderBy will
        ** be an appropriate ORDER BY expression for the optimization.
        */
        assert( minMaxFlag==WHERE_ORDERBY_NORMAL || pMinMaxOrderBy!=0 );
        assert( pMinMaxOrderBy==0 || pMinMaxOrderBy->nExpr==1 );

        SELECTTRACE(1,pParse,p,("WhereBegin-C\n"));
        pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pMinMaxOrderBy,
                                   0, minMaxFlag, 0);
        if( pWInfo==0 ){
          goto select_end;
        }
        updateAccumulator(pParse, regAcc, &sAggInfo);
        if( regAcc ) sqlite3VdbeAddOp2(v, OP_Integer, 1, regAcc);

  /* Control jumps to here if an error is encountered above, or upon
  ** successful coding of the SELECT.
  */
select_end:
  sqlite3ExprListDelete(db, pMinMaxOrderBy);
  sqlite3DbFree(db, sAggInfo.aCol);
#ifdef SQLITE_DEBUG
  if( db->mallocFailed==0 ){
    for(i=0; i<sAggInfo.nFunc; i++){
      assert( sAggInfo.aFunc[i].pExpr!=0 );
      assert( sAggInfo.aFunc[i].pExpr->pAggInfo==&sAggInfo );
      sAggInfo.aFunc[i].pExpr->pAggInfo = 0;
    }
  }
  sAggInfo.iAggMagic = 0;
#endif
  sqlite3DbFree(db, sAggInfo.aFunc);
#if SELECTTRACE_ENABLED
  SELECTTRACE(0x1,pParse,p,("end processing\n"));
  if( (sqlite3SelectTrace & 0x2000)!=0 && ExplainQueryPlanParent(pParse)==0 ){
    sqlite3TreeViewSelect(0, p, 0);
  }
#endif
  ExplainQueryPlanPop(pParse);
  return rc;
}

/*
** SELECTTRACE_ENABLED will be either 1 or 0 depending on whether or not
** the Select query generator tracing logic is turned on.
*/
#if defined(SQLITE_ENABLE_SELECTTRACE)
# define SELECTTRACE_ENABLED 1
# define SELECTTRACE(K,P,S,X)  \
  if(sqlite3SelectTrace&(K))   \
    sqlite3DebugPrintf("%u/%d/%p: ",(S)->selId,(P)->addrExplain,(S)),\
    sqlite3DebugPrintf X
#else
# define SELECTTRACE(K,P,S,X)
# define SELECTTRACE_ENABLED 0
#endif

/*
** An instance of the following structure is used to store the busy-handler
** callback for a given sqlite handle.
**

  struct AggInfo_func {   /* For each aggregate function */
    Expr *pExpr;             /* Expression encoding the function */
    FuncDef *pFunc;          /* The aggregate function implementation */
    int iMem;                /* Memory location that acts as accumulator */
    int iDistinct;           /* Ephemeral table used to enforce DISTINCT */
  } *aFunc;
  int nFunc;              /* Number of entries in aFunc[] */
#ifdef SQLITE_DEBUG
  u32 iAggMagic;          /* Sanity checking constant */
#endif
};

/*
** Allowed values for AggInfo.iAggMagic
*/
#define SQLITE_AGGMAGIC_VALID  0x05cadade

/*
** True if the AggInfo object is valid.  Used inside of assert() only.
*/
#ifdef SQLITE_DEBUG
#  define AggInfoValid(P) ((P)->iAggMagic==SQLITE_AGGMAGIC_VALID)
#endif

/*
** The datatype ynVar is a signed integer, either 16-bit or 32-bit.
** Usually it is 16-bits.  But if SQLITE_MAX_VARIABLE_NUMBER is greater
** than 32767 we have to make it 32-bit.  16-bit is preferred because
** it uses less memory in the Expr object, which is a big memory user
** in systems with lots of prepared statements.  And few applications
** need more than about 10 or 20 variables.  But some extreme users want

void sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
                          Expr*, int, int, u8);
void sqlite3DropIndex(Parse*, SrcList*, int);
int sqlite3Select(Parse*, Select*, SelectDest*);
Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
                         Expr*,ExprList*,u32,Expr*);
void sqlite3SelectDelete(sqlite3*, Select*);
void sqlite3SelectDeferredDelete(Parse*, Select*);
void sqlite3SelectReset(Parse*, Select*);
Table *sqlite3SrcListLookup(Parse*, SrcList*);
int sqlite3IsReadOnly(Parse*, Table*, int);
void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
Expr *sqlite3LimitWhere(Parse*,SrcList*,Expr*,ExprList*,Expr*,char*);
#endif

#ifndef SQLITE_AMALGAMATION
extern const unsigned char sqlite3OpcodeProperty[];
extern const char sqlite3StrBINARY[];
extern const unsigned char sqlite3UpperToLower[];
extern const unsigned char sqlite3CtypeMap[];
extern SQLITE_WSD struct Sqlite3Config sqlite3Config;
extern FuncDefHash sqlite3BuiltinFunctions;
extern u32 sqlite3SelectTrace;
#ifndef SQLITE_OMIT_WSD
extern int sqlite3PendingByte;
#endif
#endif /* !defined(SQLITE_AMALGAMATION) */
#ifdef VDBE_PROFILE
extern sqlite3_uint64 sqlite3NProfileCnt;
#endif
void sqlite3RootPageMoved(sqlite3*, int, int, int);
void sqlite3Reindex(Parse*, Token*, Token*);
void sqlite3AlterFunctions(void);
void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);

#endif
#ifdef SQLITE_TEST
#ifdef SQLITE_ENABLE_FTS3
  extern int sqlite3_fts3_enable_parentheses;
#endif
#endif
#if defined(SQLITE_ENABLE_SELECTTRACE)
  extern u32 sqlite3SelectTrace;
#endif

  for(i=0; i<sizeof(aCmd)/sizeof(aCmd[0]); i++){
    Tcl_CreateCommand(interp, aCmd[i].zName, aCmd[i].xProc, 0, 0);
  }
  for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
    Tcl_CreateObjCommand(interp, aObjCmd[i].zName, 

#ifndef SQLITE_OMIT_WINDOWFUNC
/*
** Generate a human-readable explanation for a Window Function object
*/
void sqlite3TreeViewWinFunc(TreeView *pView, const Window *pWin, u8 more){
  pView = sqlite3TreeViewPush(pView, more);
  sqlite3TreeViewLine(pView, "WINFUNC %s(%d) cur=%d",
                      pWin->pFunc->zName, pWin->pFunc->nArg,
                      pWin->iEphCsr);
  sqlite3TreeViewWindow(pView, pWin, 0);
  sqlite3TreeViewPop(pView);
}
#endif /* SQLITE_OMIT_WINDOWFUNC */

/*
** Generate a human-readable explanation of an expression tree.

        zOp2 = zBuf;
        if( pExpr->op2==NC_IsCheck ) zOp2 = "NC_IsCheck";
        if( pExpr->op2==NC_IdxExpr ) zOp2 = "NC_IdxExpr";
        if( pExpr->op2==NC_PartIdx ) zOp2 = "NC_PartIdx";
        if( pExpr->op2==NC_GenCol ) zOp2 = "NC_GenCol";
        sqlite3TreeViewLine(pView, "FUNCTION %Q%s op2=%s",
                            pExpr->u.zToken, zFlgs, zOp2);
      }else if( ExprHasProperty(pExpr, EP_WinFunc) ){
        sqlite3TreeViewLine(pView, "WINDOW-FUNCTION %Q%s cur=%d",
                            pExpr->u.zToken, zFlgs, pExpr->y.pWin->iEphCsr);
      }else{
        sqlite3TreeViewLine(pView, "FUNCTION %Q%s", pExpr->u.zToken, zFlgs);
      }
      if( pFarg ){
        sqlite3TreeViewExprList(pView, pFarg, pWin!=0, 0);
      }
#ifndef SQLITE_OMIT_WINDOWFUNC

/*
** When rewriting a query, if the new subquery in the FROM clause
** contains TK_AGG_FUNCTION nodes that refer to an outer query,
** then we have to increase the Expr->op2 values of those nodes
** due to the extra subquery layer that was added.
**
** See also the incrAggDepth() routine in resolve.c
**
** In addition to increasing pExpr->op2, set pWalker->eCode to 1 if
** any top-level aggregate functions are encountered.  This is needed
** to accurately set the SF_Aggregate flag on the new window-function
** subquery.
*/
static int sqlite3WindowExtraAggFuncDepth(Walker *pWalker, Expr *pExpr){
  if( pExpr->op==TK_AGG_FUNCTION ){
    if( pExpr->op2>=pWalker->walkerDepth ){

      pExpr->op2++;
    }else if( pExpr->op2==pWalker->walkerDepth-1 ){
      pWalker->eCode = 1;
    }
  }else if( ExprHasProperty(pExpr, EP_WinFunc) ){
    return WRC_Prune;
  }
  return WRC_Continue;
}

/*
** If the SELECT statement passed as the second argument does not invoke
** any SQL window functions, this function is a no-op. Otherwise, it 
** rewrites the SELECT statement so that window function xStep functions
** are invoked in the correct order as described under "SELECT REWRITING"
** at the top of this file.
*/
int sqlite3WindowRewrite(Parse *pParse, Select *p){
  int rc = SQLITE_OK;
  if( ALWAYS(p->pWin && (p->selFlags & SF_WinRewrite)==0) ){
    Vdbe *v = sqlite3GetVdbe(pParse);
    sqlite3 *db = pParse->db;
    Select *pSub = 0;             /* The subquery */
    SrcList *pSrc = p->pSrc;
    Expr *pWhere = p->pWhere;
    ExprList *pGroupBy = p->pGroupBy;
    Expr *pHaving = p->pHaving;
    ExprList *pSort = 0;

    ExprList *pSublist = 0;       /* Expression list for sub-query */
    Window *pMWin = p->pWin;      /* Master window object */
    Window *pWin;                 /* Window object iterator */
    Table *pTab;


    pTab = sqlite3DbMallocZero(db, sizeof(Table));
    if( pTab==0 ){
      return sqlite3ErrorToParser(db, SQLITE_NOMEM);
    }

    p->pSrc = 0;

      if( pWin->pFilter ){
        Expr *pFilter = sqlite3ExprDup(db, pWin->pFilter, 0);
        pSublist = sqlite3ExprListAppend(pParse, pSublist, pFilter);
      }
      pWin->regAccum = ++pParse->nMem;
      pWin->regResult = ++pParse->nMem;
      sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regAccum);
      VdbeComment((v, "acc of %s()", pWin->pFunc->zName));
    }

    /* If there is no ORDER BY or PARTITION BY clause, and the window
    ** function accepts zero arguments, and there are no other columns
    ** selected (e.g. "SELECT row_number() OVER () FROM t1"), it is possible
    ** that pSublist is still NULL here. Add a constant expression here to 
    ** keep everything legal in this case. 
    */
    if( pSublist==0 ){
      pSublist = sqlite3ExprListAppend(pParse, 0, 
        sqlite3Expr(db, TK_INTEGER, "0")
      );
    }

    pSub = sqlite3SelectNew(
        pParse, pSublist, pSrc, pWhere, pGroupBy, pHaving, pSort, 0, 0
    );
    SELECTTRACE(0x1,pParse,p,
                ("allocate cursors %d..%d and subquery (%d/%p) to WINDOW %p\n",
                pMWin->iEphCsr, pParse->nTab-1, pSub->selId, pSub, pMWin));
    p->pSrc = sqlite3SrcListAppend(pParse, 0, 0, 0);
    if( p->pSrc ){
      Table *pTab2;
      Walker w;
      p->pSrc->a[0].pSelect = pSub;
      sqlite3SrcListAssignCursors(pParse, p->pSrc);
      pSub->selFlags |= SF_Expanded;
      pTab2 = sqlite3ResultSetOfSelect(pParse, pSub, SQLITE_AFF_NONE);

      if( pTab2==0 ){
        /* Might actually be some other kind of error, but in that case
        ** pParse->nErr will be set, so if SQLITE_NOMEM is set, we will get
        ** the correct error message regardless. */
        rc = SQLITE_NOMEM;
      }else{
        memcpy(pTab, pTab2, sizeof(Table));
        pTab->tabFlags |= TF_Ephemeral;
        assert( pTab->zName==0 );
        pTab->zName = sqlite3MPrintf(db, "<wintab-%d>", pMWin->iEphCsr);
        p->pSrc->a[0].pTab = pTab;
        pTab = pTab2;
        memset(&w, 0, sizeof(w));
        w.xExprCallback = sqlite3WindowExtraAggFuncDepth;
        w.xSelectCallback = sqlite3WalkerDepthIncrease;
        w.xSelectCallback2 = sqlite3WalkerDepthDecrease;
        sqlite3WalkSelect(&w, pSub);
        if( w.eCode && pSub->pWin==0 ) pSub->selFlags |= SF_Aggregate;
      }
    }else{
      sqlite3SelectDelete(db, pSub);
    }
    if( db->mallocFailed ) rc = SQLITE_NOMEM;
    sqlite3DbFree(db, pTab);
  }

    FROM a
    JOIN a AS b ON a.c=4
    JOIN a AS e ON a.c=e.c
   WHERE a.c=(SELECT (SELECT coalesce(lead(2) OVER(),0) + sum(d.c))
                FROM a AS d
               WHERE a.c);
} {4 4 4 4}

#-------------------------------------------------------------------------
reset_db
do_execsql_test 54.1 {
  CREATE TABLE t1(a VARCHAR(20), b FLOAT);
  INSERT INTO t1 VALUES('1',10.0);
}

do_execsql_test 54.2 {
  SELECT * FROM ( 
    SELECT sum(b) OVER() AS c FROM t1 
      UNION
    SELECT b AS c FROM t1
  ) WHERE c>10;
}

do_execsql_test 54.3 {
  INSERT INTO t1 VALUES('2',5.0);
  INSERT INTO t1 VALUES('3',15.0);
}

do_execsql_test 54.4 {
  SELECT * FROM ( 
    SELECT sum(b) OVER() AS c FROM t1 
      UNION
    SELECT b AS c FROM t1
  ) WHERE c>10;
} {15.0 30.0}

# 2020-06-05 ticket c8d3b9f0a750a529
reset_db
do_execsql_test 55.1 {
   CREATE TABLE a(b);
   SELECT
      (SELECT b FROM a
        GROUP BY b
        HAVING (SELECT COUNT()OVER() + lead(b)OVER(ORDER BY SUM(DISTINCT b) + b))
      ) 
    FROM a
  UNION
   SELECT 99
    ORDER BY 1;
} {99}

#------------------------------------------------------------------------
reset_db
do_execsql_test 56.1 {
  CREATE TABLE t1(a, b INTEGER); 
  CREATE TABLE t2(c, d); 
}
do_catchsql_test 56.2 {
  SELECT avg(b) FROM t1 
    UNION ALL 
  SELECT min(c) OVER () FROM t2 
  ORDER BY nosuchcolumn;
} {1 {1st ORDER BY term does not match any column in the result set}}

reset_db
do_execsql_test 57.1 {
  CREATE TABLE t4(a, b, c, d, e);
}

do_catchsql_test 57.2  {
  SELECT b FROM t4
  UNION
  SELECT a FROM t4
  ORDER BY (
    SELECT sum(x) OVER() FROM (
      SELECT c AS x FROM t4
      UNION
      SELECT d FROM t4
      ORDER BY (SELECT e FROM t4)
    )
  );
} {1 {1st ORDER BY term does not match any column in the result set}}

# 2020-06-06 various dbsqlfuzz finds and
# ticket 0899cf62f597d7e7
#
reset_db
do_execsql_test 57.1 {
  CREATE TABLE t1(a, b, c);
  INSERT INTO t1 VALUES(NULL,NULL,NULL);
  SELECT 
    sum(a),
    min(b) OVER (),
    count(c) OVER (ORDER BY b)
  FROM t1;
} {{} {} 0}
do_execsql_test 57.2 {
  CREATE TABLE v0 ( v1 INTEGER PRIMARY KEY ) ; 
  INSERT INTO v0 VALUES ( 10 ) ; 
  SELECT DISTINCT v1, lead(v1) OVER() FROM v0 GROUP BY v1 ORDER BY 2;
} {10 {}}
do_execsql_test 57.3 {
  DROP TABLE t1;
  CREATE TABLE t1(a);
  INSERT INTO t1(a) VALUES(22);
  CREATE TABLE t3(y);
  INSERT INTO t3(y) VALUES(5),(11),(-9);
  SELECT (
    SELECT max(y) OVER( ORDER BY (SELECT x FROM (SELECT sum(y) AS x FROM t1)))
  )
  FROM t3;
} {5}

# 2020-06-06 ticket 1f6f353b684fc708
reset_db
do_execsql_test 58.1 {
  CREATE TABLE a(a, b, c);
  INSERT INTO a VALUES(1, 2, 3);
  INSERT INTO a VALUES(4, 5, 6);
  SELECT sum(345+b)      OVER (ORDER BY b),
         sum(avg(678)) OVER (ORDER BY c) FROM a;
} {347 678.0}

# 2020-06-06 ticket e5504e987e419fb0
do_catchsql_test 59.1 {
  DROP TABLE IF EXISTS t1;
  CREATE TABLE t1(x INTEGER PRIMARY KEY);
  INSERT INTO t1 VALUES (123);
  SELECT
     ntile( (SELECT sum(x)) ) OVER(ORDER BY x),
     min(x) OVER(ORDER BY x)
    FROM t1; 
} {1 {misuse of aggregate: sum()}}


finish_test