DÚ??? – neopisuj.
Napiš svůj názor a uvidíme, zkontrolujeme…

mysql> SELECT 23 AS bah
→ UNION
→ SELECT 45 AS bah;
±----+

±----+

±----+

2 rows in set (0.00 sec)

mysql> SELECT * FROM
→ (SELECT 23 AS bah) AS foo
→ JOIN
→ (SELECT 45 AS bah) AS bar
→ ON (33=33);
±----±----+

±----±----+

±----±----+
1 row in set (0.01 sec)