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 1.446 2008/07/02 13:13:52 danielk1977 Exp $
*/
#include "sqliteInt.h"


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

** 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 */
  int subqueryIsAgg    /* True if the subquery uses aggregate functions */
){
  const char *zSavedAuthContext = pParse->zAuthContext;
  Select *pParent;
  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 */
  ExprList *pList;    /* The result set of the outer query */
  int iParent;        /* VDBE cursor number of the pSub result set temp table */
  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.
  */
  if( p==0 ) return 0;
  pSrc = p->pSrc;
  assert( pSrc && iFrom>=0 && iFrom<pSrc->nSrc );
  pSubitem = &pSrc->a[iFrom];

      if( pSub1->isAgg || pSub1->isDistinct 
       || (pSub1->pPrior && pSub1->op!=TK_ALL) ){
        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
  ** a UNION ALL and the parent query must be of the form:
  **
  **     SELECT <expr-list> FROM (<sub-query>) <where-clause> 
  **
  ** followed by any ORDER BY, LIMIT and/or OFFSET clauses. This block
  ** creates N copies of the parent query without any ORDER BY, LIMIT or 

  */
#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];
    SelectDest dest;
    Select *pSub = pItem->pSelect;
    int isAggSub;
    char *zName = pItem->zName;

    if( pSub==0 || pItem->isPopulated ) continue;
    if( zName!=0 ){   /* An sql view */
      const char *zSavedAuthContext = pParse->zAuthContext;
      pParse->zAuthContext = zName;
      rc = sqlite3SelectResolve(pParse, pSub, 0);
      pParse->zAuthContext = zSavedAuthContext;
      if( rc ){
        goto select_end;
      }
    }

    /* Increment Parse.nHeight by the height of the largest expression
    ** tree refered to by this, the parent select. The child select
    ** may contain expression trees of at most
    ** (SQLITE_MAX_EXPR_DEPTH-Parse.nHeight) height. This is a bit
    ** more conservative than necessary, but much easier than enforcing
    ** an exact limit.
    */
    pParse->nHeight += sqlite3SelectExprHeight(p);

    /* Check to see if the subquery can be absorbed into the parent. */
    isAggSub = pSub->isAgg;
    if( flattenSubquery(pParse, p, i, isAgg, isAggSub) ){
      if( isAggSub ){
        p->isAgg = isAgg = 1;
      }
      i = -1;
    }else{
      sqlite3SelectDestInit(&dest, SRT_EphemTab, pItem->iCursor);
      sqlite3Select(pParse, pSub, &dest, p, i, &isAgg, 0);
    }
    if( pParse->nErr || db->mallocFailed ){
      goto select_end;
    }
    pParse->nHeight -= sqlite3SelectExprHeight(p);
    pTabList = p->pSrc;
    if( !IgnorableOrderby(pDest) ){
      pOrderBy = p->pOrderBy;
    }

#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is testing the sqlite3_set_authorizer() API
# and related functionality.
#
# $Id: auth.test,v 1.43 2008/07/02 13:13:52 danielk1977 Exp $
#

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

# disable this test if the SQLITE_OMIT_AUTHORIZATION macro is
# defined during compilation.

  SQLITE_UPDATE v1     x  main {} \
  SQLITE_INSERT v1chng {} main r2 \
  SQLITE_READ   v1     x  main r2 \
  SQLITE_READ   v1     x  main r2 \
  SQLITE_SELECT {}     {} {}   v1 \
  SQLITE_READ   t2     a  main v1 \
  SQLITE_READ   t2     b  main v1 \
  SQLITE_SELECT {}     {} {}   {} \
  SQLITE_READ   v1     x  main v1 \
]
do_test auth-4.4 {
  execsql {
    CREATE TRIGGER r3 INSTEAD OF DELETE ON v1 BEGIN
      INSERT INTO v1chng VALUES(OLD.x,NULL);
    END;

} [list \
  SQLITE_DELETE v1     {} main {} \
  SQLITE_INSERT v1chng {} main r3 \
  SQLITE_READ   v1     x  main r3 \
  SQLITE_SELECT {}     {} {}   v1 \
  SQLITE_READ   t2     a  main v1 \
  SQLITE_READ   t2     b  main v1 \
  SQLITE_SELECT {}     {} {}   {} \
  SQLITE_READ   v1     x  main v1 \
]

} ;# ifcapable view && trigger

# Ticket #1338:  Make sure authentication works in the presence of an AS
# clause.

#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is testing the sqlite3_set_authorizer() API
# and related functionality.
#
# $Id: auth2.test,v 1.3 2008/07/02 13:13:53 danielk1977 Exp $
#

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

# disable this test if the SQLITE_OMIT_AUTHORIZATION macro is
# defined during compilation.

  db eval {
    SELECT a, b FROM v2;
  }
  set ::authargs
} {SQLITE_SELECT {} {} {} {}
SQLITE_READ v2 a main {}
SQLITE_READ v2 b main {}

SQLITE_READ t2 x main v2
SQLITE_READ t2 y main v2
SQLITE_READ t2 y main v2
SQLITE_READ t2 z main v2
SQLITE_SELECT {} {} {} v2
}
do_test auth2-2.4 {
  db2 eval {
    CREATE TABLE t3(p,q,r);
  }
  set ::authargs {}
  db eval {
    SELECT b, a FROM v2;
  }
  set ::authargs
} {SQLITE_SELECT {} {} {} {}
SQLITE_READ v2 b main {}
SQLITE_READ v2 a main {}

SQLITE_READ t2 x main v2
SQLITE_READ t2 y main v2
SQLITE_READ t2 y main v2
SQLITE_READ t2 z main v2
SQLITE_SELECT {} {} {} v2
SQLITE_SELECT {} {} {} {}
SQLITE_READ v2 b main {}
SQLITE_READ v2 a main {}

SQLITE_READ t2 x main v2
SQLITE_READ t2 y main v2
SQLITE_READ t2 y main v2
SQLITE_READ t2 z main v2
SQLITE_SELECT {} {} {} v2
}
db2 close

finish_test