sql - How to check if field is null or empty in MySQL?

Question

I am trying to figure out how to check if a field is NULL or empty. I have this:

SELECT IFNULL(field1, 'empty') as field1 from tablename

I need to add an additional check field1 != "" something like:

SELECT IFNULL(field1, 'empty') OR field1 != ""  as field1 from tablename

Any idea how to accomplish this?

Answer 1

Either use

SELECT IF(field1 IS NULL or field1 = '', 'empty', field1) as field1 
from tablename

or

SELECT case when field1 IS NULL or field1 = ''
            then 'empty'
            else field1
       end as field1 
from tablename

If you only want to check for null and not for empty strings then you can also use ifnull() or coalesce(field1, 'empty'). But that is not suitable for empty strings.