create table t1 (a int auto_increment, b int, PRIMARY KEY (a)) ENGINE=InnoDB;
create table t2 (a int auto_increment, b int, PRIMARY KEY (a)) ENGINE=MyISAM;
create table t3 (a int auto_increment, b int, PRIMARY KEY (a)) ENGINE=InnoDB;
select get_lock("a", 20);
get_lock("a", 20)
1
reset master;
insert into t2 values (null, null), (null, get_lock("a", 10));
select @result /* must be zero either way */;
@result
0
select RELEASE_LOCK("a");
RELEASE_LOCK("a")
1
delete from t1;
delete from t2;
insert into t1 values (1,1),(2,2);
begin;
update t1 set b=11 where a=2;
begin;
update t1 set b=b+10;
kill query ID;
rollback;
rollback;
select * from t1  order by a /* must be the same as before (1,1),(2,2) */;
a	b
1	1
2	2
begin;
delete from t1 where a=2;
begin;
delete from t1 where a=2;
kill query ID;
rollback;
rollback;
select * from t1 order by a /* must be the same as before (1,1),(2,2) */;
a	b
1	1
2	2
drop table if exists t4;
create table t4 (a int, b int) engine=innodb;
insert into t4 values (3, 3);
begin;
insert into t1 values (3, 3);
begin;
insert into t1 select * from t4 for update;
kill query ID;
rollback;
rollback;
select * from t1 /* must be the same as before (1,1),(2,2) */;
a	b
1	1
2	2
drop table t4;
drop table t1,t2,t3;
end of the tests