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
** in order to generate code for DELETE FROM statements.
**
** $Id: delete.c,v 1.185 2008/10/27 15:34:33 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** Look up every table that is named in pSrc.  If any table is not found,
** add an error message to pParse->zErrMsg and return NULL.  If all tables
** are found, return a pointer to the last table.

  int iCur;              /* VDBE Cursor number for pTab */
  sqlite3 *db;           /* Main database structure */
  AuthContext sContext;  /* Authorization context */
  int oldIdx = -1;       /* Cursor for the OLD table of AFTER triggers */
  NameContext sNC;       /* Name context to resolve expressions in */
  int iDb;               /* Database number */
  int memCnt = -1;       /* Memory cell used for change counting */
  int rcauth;            /* Value returned by authorization callback */

#ifndef SQLITE_OMIT_TRIGGER
  int isView;                  /* True if attempting to delete from a view */
  int triggers_exist = 0;      /* True if any triggers exist */
#endif
  int iBeginAfterTrigger;      /* Address of after trigger program */
  int iEndAfterTrigger;        /* Exit of after trigger program */

  if( sqlite3IsReadOnly(pParse, pTab, triggers_exist) ){
    goto delete_from_cleanup;
  }
  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
  assert( iDb<db->nDb );
  zDb = db->aDb[iDb].zName;
  rcauth = sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb);
  assert( rcauth==SQLITE_OK || rcauth==SQLITE_DENY || rcauth==SQLITE_IGNORE );
  if( rcauth==SQLITE_DENY ){
    goto delete_from_cleanup;
  }
  assert(!isView || triggers_exist);

  /* If pTab is really a view, make sure it has been initialized.
  */
  if( sqlite3ViewGetColumnNames(pParse, pTab) ){

  }

#ifndef SQLITE_OMIT_TRUNCATE_OPTIMIZATION
  /* Special case: A DELETE without a WHERE clause deletes everything.
  ** It is easier just to erase the whole table.  Note, however, that
  ** this means that the row change count will be incorrect.
  */
  if( rcauth==SQLITE_OK && pWhere==0 && !triggers_exist && !IsVirtual(pTab) ){
    assert( !isView );
    sqlite3VdbeAddOp3(v, OP_Clear, pTab->tnum, iDb, memCnt);
    if( !pParse->nested ){
      sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_STATIC);
    }
    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
      assert( pIdx->pSchema==pTab->pSchema );

#    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 1.44 2008/10/27 15:34:33 danielk1977 Exp $
#

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

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

    }
    return SQLITE_OK
  }
  catchsql {DELETE FROM t2 WHERE a=11}
} {0 {}}
do_test auth-1.50 {
  execsql {SELECT * FROM t2}
} {}
do_test auth-1.50.2 {
  execsql {INSERT INTO t2 VALUES(11, 2, 33)}
} {}

do_test auth-1.51 {
  proc auth {code arg1 arg2 arg3 arg4} {
    if {$code=="SQLITE_SELECT"} {
      return SQLITE_DENY
    }
    return SQLITE_OK

# 2008 October 27
#
# 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.
#
#***********************************************************************
#
# Test that the truncate optimization is disabled if the SQLITE_DELETE
# authorization callback returns SQLITE_IGNORE.
#
# $Id: auth3.test,v 1.1 2008/10/27 15:34:33 danielk1977 Exp $
#

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

# disable this test if the SQLITE_OMIT_AUTHORIZATION macro is
# defined during compilation.
if {[catch {db auth {}} msg]} {
  finish_test
  return
}

# Disable the statement cache for these tests.
# 
db cache size 0

db authorizer ::auth
proc auth {code arg1 arg2 arg3 arg4} {
  if {$code=="SQLITE_DELETE"} {
    return $::authcode
  }
  return SQLITE_OK
}

#--------------------------------------------------------------------------
# The following tests - auth3-1.* - test that return values of SQLITE_DENY,
# SQLITE_IGNORE, SQLITE_OK and <invalid> are correctly handled when returned
# by an SQLITE_DELETE authorization callback triggered by a 
# "DELETE FROM <table-name>" statement.
#
do_test auth3-1.1 {
  execsql {
    CREATE TABLE t1(a,b,c);
    INSERT INTO t1 VALUES(1, 2, 3);
    INSERT INTO t1 VALUES(4, 5, 6);
  }
} {}
do_test auth3.1.2 {
  set ::authcode SQLITE_DENY
  catchsql { DELETE FROM t1 }
} {1 {not authorized}}
do_test auth3.1.3 {
  set ::authcode SQLITE_INVALID
  catchsql { DELETE FROM t1 }
} {1 {illegal return value (1) from the authorization function - should be SQLITE_OK, SQLITE_IGNORE, or SQLITE_DENY}}
do_test auth3.1.4 {
  execsql { SELECT * FROM t1 }
} {1 2 3 4 5 6}
do_test auth3-1.5 {
  set ::authcode SQLITE_IGNORE
  execsql { 
    DELETE FROM t1;
    SELECT * FROM t1;
  }
} {}
do_test auth3-1.6 {
  set ::authcode SQLITE_OK
  execsql {
    INSERT INTO t1 VALUES(1, 2, 3);
    INSERT INTO t1 VALUES(4, 5, 6);
    DELETE FROM t1;
    SELECT * FROM t1;
  }
} {}

#--------------------------------------------------------------------------
# These tests - auth3-2.* - test that returning SQLITE_IGNORE really does
# disable the truncate optimization.
#
do_test auth3-2.1 {
  set ::authcode SQLITE_OK
  execsql {
    INSERT INTO t1 VALUES(1, 2, 3);
    INSERT INTO t1 VALUES(4, 5, 6);
  }
  set sqlite_search_count 0
  execsql {
    DELETE FROM t1;
  }
  set sqlite_search_count
} {0}

do_test auth3-2.2 {
  set ::authcode SQLITE_IGNORE
  execsql {
    INSERT INTO t1 VALUES(1, 2, 3);
    INSERT INTO t1 VALUES(4, 5, 6);
  }
  set sqlite_search_count 0
  execsql {
    DELETE FROM t1;
  }
  set sqlite_search_count
} {1}

finish_test