Question

SELECT IFNULL(Col,'b') FROM Table

Checks Col and returns Col if is not null if not it returns b.

How do I check Col, and return ‘a’ if not null or ‘b’ if null.

I tried this:

SELECT IF(Col=NULL,'a','b') FROM Table

Which always returns ‘b’. How is this done?

Answer 1

Use IS NULL to check whether a column is null, instead of = NULL.

Every value compares with NULL the result will be NULL, so you will always get b.

SELECT IF(Col IS NULL,'a','b') FROM Table