Treat [BLANK] and NULL as the same

I am being asked to use a database that is full of [BLANK] and NULL values in the same column. So if I want to insert an App Connect Binding with a Ternary Operation (if/else) and want “if [BLANK] or NULL put nothing else put value” do I always have to put this as the expression?

(old_code == '' || old_code == null) ? '' : old_code

Or is there a simpler way to look for [BLANK] or NULL ?

Is the following the correct way to do it and will it always capture the [BLANK] or NULL ?

old_code ? old_code : ''

It’s not a problem, I am just asking for clarity