mySQL query: How to insert with UNION?

Question

I am kind of new to mySQL:s union functions, at least when doing inserts with them. I have gotten the following to work based upon a example found on the net:

INSERT INTO tableOne(a, b)
SELECT a, $var FROM tableOne
WHERE b = $var2
UNION ALL SELECT $var,$var

Ok, nothing strange about that. But what happens when I want to insert a third value into the database that has nothing to do with the logic of the Select being done?

Like : INSERT INTO tableOne(a, b, c )

How could that be done?

Solution

You can "select" literal values too:

mysql> select 'hello', 1;
+-------+---+
| hello | 1 |
+-------+---+
| hello | 1 |
+-------+---+
1 row in set (0.00 sec)

Hence, you can also use that in INSERT INTO ... SELECT FROM and UNIONs.

INSERT INTO someTable (a, b, c) VALUES
SELECT id, name, 5
FROM someOtherTable
UNION
SELECT id, alias, 8
FROM anotherTable