By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.
CREATE TABLE t1
AS
SELECT 1 AS id, 'A' AS col
UNION
SELECT 2 AS id, 'B' AS col
✓
CREATE TABLE t2
AS
SELECT 1 AS id, 999 AS val
UNION
SELECT 3 AS id, 100 AS val
✓
SELECT *
FROM t1
FULL JOIN t2
ON t1.id = t2.id
| id | col | id | val |
|---|---|---|---|
| 1 | A | 1 | 999 |
| 2 | B | null | null |
| null | null | 3 | 100 |