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/* Copyright (C) 2000-2006 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/*
OLAP implementation by Sinisa Milivojevic <sinisa@mysql.com>
Inspired by code submitted by Srilakshmi <lakshmi@gdit.iiit.net>
The ROLLUP code in this file has to be complitely rewritten as it's
not good enough to satisfy the goals of MySQL.
In 4.1 we will replace this with a working, superior implementation
of ROLLUP.
*/
#ifdef DISABLED_UNTIL_REWRITTEN_IN_4_1
#ifdef USE_PRAGMA_IMPLEMENTATION
#pragma implementation // gcc: Class implementation
#endif
#include "mysql_priv.h"
#include "sql_select.h"
/****************************************************************************
Functions that recursively actually creates new SELECT's
Returns 0 if OK, 1 if error, -1 if error already printed to client
****************************************************************************/
static int make_new_olap_select(LEX *lex, SELECT_LEX *select_lex, List<Item> new_fields)
{
THD *thd=current_thd;
Item *item, *new_item;
Item_null *constant= new Item_null("ALL");
SELECT_LEX *new_select = (SELECT_LEX *) thd->memdup((char*) select_lex, sizeof(*select_lex));
if (!new_select)
return 1;
lex->last_selects->next=new_select;
new_select->linkage=OLAP_TYPE;
new_select->olap=NON_EXISTING_ONE;
new_select->group_list.elements=0;
new_select->group_list.first=(uchar *)0;
new_select->group_list.next=(uchar **)&new_select->group_list.first;
List<Item> privlist;
List_iterator<Item> list_it(select_lex->item_list);
List_iterator<Item> new_it(new_fields);
while ((item=list_it++))
{
bool not_found= TRUE;
if (item->type()==Item::FIELD_ITEM)
{
Item_field *iif = (Item_field *)item;
new_it.rewind();
while ((new_item=new_it++))
{
if (new_item->type()==Item::FIELD_ITEM &&
!strcmp(((Item_field*)new_item)->table_name,iif->table_name) &&
!strcmp(((Item_field*)new_item)->field_name,iif->field_name))
{
not_found= 0;
((Item_field*)new_item)->db_name=iif->db_name;
Item_field *new_one=new Item_field(&select_lex->context,
iif->db_name, iif->table_name, iif->field_name);
privlist.push_back(new_one);
if (add_to_list(new_select->group_list,new_one,1))
return 1;
break;
}
}
}
if (not_found)
{
if (item->type() == Item::FIELD_ITEM)
privlist.push_back(constant);
else
privlist.push_back((Item*)thd->memdup((char *)item,item->size_of()));
}
}
new_select->item_list=privlist;
lex->last_selects = new_select;
return 0;
}
/****************************************************************************
Functions that recursively creates combinations of queries for OLAP
Returns 0 if OK, 1 if error, -1 if error already printed to client
****************************************************************************/
static int olap_combos(List<Item> old_fields, List<Item> new_fields, Item *item, LEX *lex,
SELECT_LEX *select_lex, int position, int selection, int num_fields,
int num_new_fields)
{
int sl_return = 0;
if (position == num_new_fields)
{
if (item)
new_fields.push_front(item);
sl_return = make_new_olap_select(lex, select_lex, new_fields);
}
else
{
if (item)
new_fields.push_front(item);
while ((num_fields - num_new_fields >= selection - position) && !sl_return)
{
item = old_fields.pop();
sl_return = olap_combos(old_fields, new_fields, item, lex, select_lex, position+1, ++selection, num_fields, num_new_fields);
}
}
return sl_return;
}
/****************************************************************************
Top level function for converting OLAP clauses to multiple selects
This is also a place where clauses treatment depends on OLAP type
Returns 0 if OK, 1 if error, -1 if error already printed to client
****************************************************************************/
int handle_olaps(LEX *lex, SELECT_LEX *select_lex)
{
List<Item> item_list_copy, new_item_list;
item_list_copy.empty();
new_item_list.empty();
int count=select_lex->group_list.elements;
int sl_return=0;
lex->last_selects=select_lex;
for (ORDER *order=(ORDER *)select_lex->group_list.first ; order ; order=order->next)
item_list_copy.push_back(*(order->item));
List<Item> all_fields(select_lex->item_list);
if (setup_tables(lex->thd, &select_lex->context, &select_lex->top_join_list,
(TABLE_LIST *)select_lex->table_list.first
&select_lex->leaf_tables, FALSE) ||
setup_fields(lex->thd, 0, select_lex->item_list, MARK_COLUMNS_READ,
&all_fields,1) ||
setup_fields(lex->thd, 0, item_list_copy, MARK_COLUMNS_READ,
&all_fields, 1))
return -1;
if (select_lex->olap == CUBE_TYPE)
{
for ( int i=count-1; i>=0 && !sl_return; i--)
sl_return=olap_combos(item_list_copy, new_item_list, (Item *)0, lex, select_lex, 0, 0, count, i);
}
else if (select_lex->olap == ROLLUP_TYPE)
{
for ( int i=count-1; i>=0 && !sl_return; i--)
{
Item *item;
item_list_copy.pop();
List_iterator<Item> it(item_list_copy);
new_item_list.empty();
while ((item = it++))
new_item_list.push_front(item);
sl_return=make_new_olap_select(lex, select_lex, new_item_list);
}
}
else
sl_return=1; // impossible
return sl_return;
}
#endif /* DISABLED_UNTIL_REWRITTEN_IN_4_1 */
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