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mariadb/sql/sql_unions.cc
Sinisa@sinisa.nasamreza.org 147de1e568 UNION stuff mainly.
2001-07-11 14:06:41 +03:00

102 lines
2.3 KiB
C++

#include "mysql_priv.h"
/* Union of selects */
int mysql_union(THD *thd,LEX *lex,uint no_of_selects)
{
SELECT_LEX *sl, *for_order=&lex->select_lex; uint no=0; int res;
List<Item> fields; TABLE *table;
for (;for_order->next;for_order=for_order->next);
ORDER *some_order = (ORDER *)for_order->order_list.first;
for (sl=&lex->select_lex;sl;sl=sl->next, no++)
{
TABLE_LIST *tables=(TABLE_LIST*) sl->table_list.first;
if (!no) // First we do CREATE from SELECT
{
select_create *result;
lex->create_info.options=HA_LEX_CREATE_TMP_TABLE;
if ((result=new select_create(tables->db ? tables->db : thd->db,
NULL, &lex->create_info,
lex->create_list,
lex->key_list,
sl->item_list,DUP_IGNORE)))
{
res=mysql_select(thd,tables,sl->item_list,
sl->where,
sl->ftfunc_list,
(ORDER*) NULL,
(ORDER*) sl->group_list.first,
sl->having,
(ORDER*) some_order,
sl->options | thd->options,
result);
if (res)
{
result->abort();
delete result;
return res;
}
else
{
table=result->table;
List_iterator<Item> it(*(result->fields));
Item *item;
while ((item= it++))
fields.push_back(item);
}
delete result;
if (reopen_table(table)) return 1;
}
else
return -1;
}
else // Then we do INSERT from SELECT
{
select_result *result;
if ((result=new select_insert(table, &fields, DUP_IGNORE)))
{
res=mysql_select(thd,tables,sl->item_list,
sl->where,
sl->ftfunc_list,
(ORDER*) some_order,
(ORDER*) sl->group_list.first,
sl->having,
(ORDER*) NULL,
sl->options | thd->options,
result);
delete result;
if (res) return 1;
}
else
return -1;
}
}
if (1) // Meaning if not SELECT ... INTO .... which will be done later
{
READ_RECORD info;
int error=0;
if (send_fields(thd,fields,1)) return 1;
SQL_SELECT *select= new SQL_SELECT;
select->head=table;
select->file=*(table->io_cache);
init_read_record(&info,thd,table,select,1,1);
while (!(error=info.read_record(&info)) && !thd->killed)
{
if (error)
{
table->file->print_error(error,MYF(0));
break;
}
}
end_read_record(&info);
delete select;
}
else
{
}
return 0;
}