ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'select count(*) from mysql.user)' at line 1
create table t1 (id int primary key);
create table t2 (id int unsigned not null);
insert into t2 select id from t1;
create table t3 (kill_id int);
insert into t3 values(connection_id());
select id from t1 where id in (select distinct id from t2);