I have a lot of tables using an 'item_status' field. These do diferent things for different tables and some have more options than others.
The problem is that with all the initial coding I use numbers for db entries:

Now when I added the validation routines 0, '' and empty are the same thing.
And have found that checkboxes only have an 'on' option the off is empty.
Is there a way I can validate these without having to rewrite all my datatables?