Commit d9b81f3a authored by unknown's avatar unknown

EXISTS(SELECT * ...)

close table before opening in optimize


mysql-test/r/subselect.result:
  test of EXISTS(SELECT * ...)
mysql-test/t/subselect.test:
  test of EXISTS(SELECT * ...)
sql/sql_base.cc:
  EXISTS(SELECT * ...)
sql/sql_table.cc:
  close table before opening one
parent f9ec1ff2
...@@ -328,10 +328,10 @@ patient_uq clinic_uq ...@@ -328,10 +328,10 @@ patient_uq clinic_uq
explain extended select * from t6 where exists (select * from t7 where uq = clinic_uq); explain extended select * from t6 where exists (select * from t7 where uq = clinic_uq);
id select_type table type possible_keys key key_len ref rows Extra id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t6 ALL NULL NULL NULL NULL 4 Using where 1 PRIMARY t6 ALL NULL NULL NULL NULL 4 Using where
2 DEPENDENT SUBQUERY t7 eq_ref PRIMARY PRIMARY 4 test.t6.clinic_uq 1 2 DEPENDENT SUBQUERY t7 eq_ref PRIMARY PRIMARY 4 test.t6.clinic_uq 1 Using index
Warnings: Warnings:
Note 1276 Field or reference 'clinic_uq' of SELECT #2 was resolved in SELECT #1 Note 1276 Field or reference 'clinic_uq' of SELECT #2 was resolved in SELECT #1
Note 1003 select test.t6.patient_uq AS `patient_uq`,test.t6.clinic_uq AS `clinic_uq` from test.t6 where exists(select test.t7.uq AS `uq`,test.t7.name AS `name` from test.t7 where (test.t7.uq = test.t6.clinic_uq)) Note 1003 select test.t6.patient_uq AS `patient_uq`,test.t6.clinic_uq AS `clinic_uq` from test.t6 where exists(select 1 AS `Not_used` from test.t7 where (test.t7.uq = test.t6.clinic_uq))
select * from t1 where a= (select a from t2,t4 where t2.b=t4.b); select * from t1 where a= (select a from t2,t4 where t2.b=t4.b);
ERROR 23000: Column: 'a' in field list is ambiguous ERROR 23000: Column: 'a' in field list is ambiguous
drop table t1,t2,t3; drop table t1,t2,t3;
...@@ -1817,3 +1817,17 @@ a ...@@ -1817,3 +1817,17 @@ a
1 1
3 3
DROP TABLE t1; DROP TABLE t1;
create table t1 (a int, b int);
insert into t1 values (1,2),(3,4);
select * from t1 up where exists (select * from t1 where t1.a=up.a);
a b
1 2
3 4
explain extended select * from t1 up where exists (select * from t1 where t1.a=up.a);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY up ALL NULL NULL NULL NULL 2 Using where
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 2 Using where
Warnings:
Note 1276 Field or reference 'up.a' of SELECT #2 was resolved in SELECT #1
Note 1003 select test.up.a AS `a`,test.up.b AS `b` from test.t1 up where exists(select 1 AS `Not_used` from test.t1 where (test.t1.a = test.up.a))
drop table t1;
...@@ -1158,3 +1158,12 @@ SELECT a FROM t1 WHERE a >= ALL ( SELECT a FROM t1 WHERE b = 2 ); ...@@ -1158,3 +1158,12 @@ SELECT a FROM t1 WHERE a >= ALL ( SELECT a FROM t1 WHERE b = 2 );
SELECT a FROM t1 WHERE a <= ALL ( SELECT a FROM t1 WHERE b = 2 ); SELECT a FROM t1 WHERE a <= ALL ( SELECT a FROM t1 WHERE b = 2 );
SELECT a FROM t1 WHERE a <> ALL ( SELECT a FROM t1 WHERE b = 2 ); SELECT a FROM t1 WHERE a <> ALL ( SELECT a FROM t1 WHERE b = 2 );
DROP TABLE t1; DROP TABLE t1;
#
# SELECT(EXISTS * ...)optimisation
#
create table t1 (a int, b int);
insert into t1 values (1,2),(3,4);
select * from t1 up where exists (select * from t1 where t1.a=up.a);
explain extended select * from t1 up where exists (select * from t1 where t1.a=up.a);
drop table t1;
...@@ -2184,7 +2184,18 @@ int setup_wild(THD *thd, TABLE_LIST *tables, List<Item> &fields, ...@@ -2184,7 +2184,18 @@ int setup_wild(THD *thd, TABLE_LIST *tables, List<Item> &fields,
!((Item_field*) item)->field) !((Item_field*) item)->field)
{ {
uint elem= fields.elements; uint elem= fields.elements;
if (insert_fields(thd,tables,((Item_field*) item)->db_name, Item_subselect *subsel= thd->lex->current_select->master_unit()->item;
if (subsel &&
subsel->substype() == Item_subselect::EXISTS_SUBS)
{
/*
It is EXISTS(SELECT * ...) and we can replace * by any constant.
Item_int do not need fix_fields() because it is basic constant.
*/
it.replace(new Item_int("Not_used", (longlong) 1, 21));
}
else if (insert_fields(thd,tables,((Item_field*) item)->db_name,
((Item_field*) item)->table_name, &it)) ((Item_field*) item)->table_name, &it))
{ {
if (stmt) if (stmt)
......
...@@ -1861,6 +1861,7 @@ static int mysql_admin_table(THD* thd, TABLE_LIST* tables, ...@@ -1861,6 +1861,7 @@ static int mysql_admin_table(THD* thd, TABLE_LIST* tables,
TABLE_LIST *save_next= table->next; TABLE_LIST *save_next= table->next;
table->next= 0; table->next= 0;
result_code= mysql_recreate_table(thd, table, 0); result_code= mysql_recreate_table(thd, table, 0);
close_thread_tables(thd);
if (!result_code) // recreation went ok if (!result_code) // recreation went ok
{ {
if ((table->table= open_ltable(thd, table, lock_type)) && if ((table->table= open_ltable(thd, table, lock_type)) &&
......
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