database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-29 05:21:33 +03:00
Code Activity

MDEV-28285 Unexpected result when combining DISTINCT, subselect and LIMIT

Browse Source 
The problem was that when  JOIN_TAB::remove_duplicates() noticed there
can only be one possible row in the output, it adjusted limits but
didn't take into account any possible offset.

Fixed by not adjusting limit offset when setting one-row-limit.
This commit is contained in:
Monty
2023-05-22 18:58:45 +03:00
parent cd37e49422
commit 92d2ceac73
4 changed files with 56 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
mysql-test/main/distinct.test
View File

@ -892,3 +892,24 @@ explain select * from t1 limit 0;
explain select * from t1 limit 0 offset 10;
drop table t1, t2;
--echo #
--echo # MDEV-28285 Unexpected result when combining DISTINCT, subselect
--echo # and LIMIT
--echo #
create table t1 (a int primary key);
create table t2 (a int primary key, b int not null);
insert into t1 select seq from seq_1_to_10;
insert into t2 select seq,seq from seq_1_to_10;
select distinct a from t1 where t1.a=1 and t1.a in (select a from t2 where t2.b in (1,2));
explain select distinct a from t1 where t1.a=1 and t1.a in (select a+0 from t2 where t2.b in (1,2)) limit 10,10;
select distinct a from t1 where t1.a=1 and t1.a in (select a+0 from t2 where t2.b in (1,2)) limit 10,10;
select distinct a from t1 where t1.a=1 and t1.a in (select a+0 from t2 where t2.b in (1,2)) limit 0,1;
drop table t1,t2;
--echo #
--echo # end of 10.5 tests
--echo #