Is there a reason MySQL doesn't support FULL OUTER JOINS?

Question

Is there a reason MySQL doesn\'t support FULL OUTER JOINS? I\'ve tried full outer join syntax in mysql many times and it never worked, just found out its not supported by my

Answer 1

I don't believe the MySQL devs have ever stated any technical reason why it might be difficult to implement.

But MySQL, like most DBMSs, has many places where it does not fully implement the ANSI standard. Since FULL OUTER JOIN is a rarely-used feature, and can typically be replaced by a UNION workaround, there is little pressure to get it fixed.

I suggest adding your voice to bug 18003.