SQLite

**    May you find forgiveness for yourself and forgive others.
**    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.
**
** $Id: select.c,v 1.448 2008/07/08 17:43:57 danielk1977 Exp $
*/
#include "sqliteInt.h"


/*
** Delete all the content of a Select structure but do not deallocate
** the select structure itself.

**          * is not itself part of a compound select,
**          * is not an aggregate or DISTINCT query, and
**          * has no other tables or sub-selects in the FROM clause.
**
**        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.
**
**  (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.
**
** 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 and subqueryIsAgg is true if the subquery uses aggregates.
**
** If flattening is not attempted, this routine is a no-op and returns 0.
** If flattening is attempted this routine returns 1.

  /* Check to see if flattening is permitted.  Return 0 if not.
  */
  if( p==0 ) 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 );
  if( isAgg && subqueryIsAgg ) return 0;                 /* Restriction (1)  */
  if( subqueryIsAgg && pSrc->nSrc>1 ) return 0;          /* Restriction (2)  */
  pSubSrc = pSub->pSrc;
  assert( pSubSrc );
  /* Prior to version 3.1.2, when LIMIT and OFFSET had to be simple constants,

    }
    for(pSub1=pSub; pSub1; pSub1=pSub1->pPrior){
      if( pSub1->isAgg || pSub1->isDistinct 
       || (pSub1->pPrior && pSub1->op!=TK_ALL) ){
        return 0;
      }
    }

    /* Restriction 18. */
    if( p->pOrderBy ){
      int ii;
      for(ii=0; ii<p->pOrderBy->nExpr; ii++){
        Expr *pExpr = p->pOrderBy->a[ii].pExpr;
        if( pExpr->op!=TK_COLUMN || pExpr->iTable!=iParent ){ 
          return 0;
        }
      }
    }
  }

  pParse->zAuthContext = pSubitem->zName;
  sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0);
  pParse->zAuthContext = zSavedAuthContext;

  /* If the sub-query is a compound SELECT statement, then it must be

    pNew->pRightmost = 0;
  }

  /* If we reach this point, it means flattening is permitted for the
  ** iFrom-th entry of the FROM clause in the outer query.
  */
  pSub = pSub1 = pSubitem->pSelect;

  for(pParent=p; pParent; pParent=pParent->pPrior, pSub=pSub->pPrior){
    int nSubSrc = pSubSrc->nSrc;
    int jointype = 0;
    pSubSrc = pSub->pSrc;
    pSrc = pParent->pSrc;

    /* Move all of the FROM elements of the subquery into the

# 2007 May 1
#
# 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.
#
#***********************************************************************
#
# $Id: incrblob_err.test,v 1.12 2008/07/08 17:43:57 danielk1977 Exp $
#

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

ifcapable {!incrblob  || !memdebug || !tclvar} {
  finish_test

  # map page for the purposes of seeking to the end of the blob.
  #
  sqlite3 db2 test.db
  set ::blob [db2 incrblob blobs v 1]
  sqlite3_blob_write $::blob [expr 500*1020-20] 12345678900987654321
  close $::blob
}

db2 close

finish_test

# 2008 June 24
#
# 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. 
#
# $Id: selectB.test,v 1.6 2008/07/08 17:43:57 danielk1977 Exp $

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

proc test_transform {testname sql1 sql2 results} {
  set ::vdbe1 [list]
  set ::vdbe2 [list]

  do_test selectB-$ii.20 {
    execsql {
      SELECT DISTINCT * FROM (
        SELECT DISTINCT (a/10) FROM t1 UNION ALL SELECT DISTINCT(d%2) FROM t2
      )
    }
  } {0 1}

  do_test selectB-$ii.21 {
    execsql {
      SELECT * FROM (SELECT * FROM t1 UNION ALL SELECT * FROM t2) ORDER BY a+b
    }
  } {2 4 6 3 6 9 8 10 12 12 15 18 14 16 18 21 24 27}
}

finish_test