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);
    }
  }

    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

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

  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}

finish_test