U kunt ook letterlijke waarden "selecteren":
mysql> select 'hello', 1;
+-------+---+
| hello | 1 |
+-------+---+
| hello | 1 |
+-------+---+
1 row in set (0.00 sec)
Daarom kun je dat ook gebruiken in INSERT INTO ... SELECT FROM
en UNION
v.
INSERT INTO someTable (a, b, c) VALUES
SELECT id, name, 5
FROM someOtherTable
UNION
SELECT id, alias, 8
FROM anotherTable