MySQL order over multiple statements

Question

I have a situation where I need to sort my records by their "status", which consists of a combination of fields. Here is an example of how it should return results sorted by status in ascending order:

| Sent Received Approved -------------------------------------------------- record1 | null null null record2 | 2012-01-01 null null record3 | 2012-01-01 2012-01-01 null record4 | 2012-01-01 2012-01-01 2012-01-01 

How do I create a MySQL query that will order these records by their common "status"?

Answer 1

 order by case when sent is null and received is null and approved is null then 1 when received is null and approved is null then 2 when approved is null then 3 else 4 end