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CREATE TABLE a (id int, b_id int)
CREATE TABLE b (id int)
INSERT INTO a VALUES (1, 1), (1, 2), (1, 3), (2, 2), (3, 2), (3, 3)
6 rows affected
SELECT a.id FROM a
JOIN b on a.b_id = b.id
GROUP BY a.id
HAVING COUNT(a.id) = (SELECT COUNT(*) FROM b)
UNION
SELECT a.id
FROM a
WHERE NOT EXISTS (SELECT 1 FROM b)
| id |
|---|
| 1 |
| 2 |
| 3 |