create database cviko2;

use cviko2;

drop table if not exists T1;
drop table if not exists T2;

create temporary table T1(a int);
insert T1 values (1), (1), (2);

create temporary table T2(a int, b int);
insert T2 values (1,1), (1,2), (2,1);

SELECT T1.a, T2.a, T2.b FROM T1 JOIN T2 ON T2.a = T1.a;