SQLite

    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.  
*/

      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 ) ){
      sqlite3WindowRewrite(pParse, p);
#if SELECTTRACE_ENABLED
      if( (sqlite3SelectTrace & 0x108)!=0 ){
        SELECTTRACE(0x104,pParse,p, ("after window rewrite:\n"));
        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;

  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.
  */

  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

  }
#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

  /* 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
  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

#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, 

** 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;

    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}

finish_test