AllowZeroLength vs NOT NULL

[Dale Schmitz]

I'm converting an Access 97 app to MySQL with web pages and such via an AMP stack and I am a little confused over a couple of differences. I'm hoping I can get clarification here.

I've executed the Database Documenter in Access and have a rather large text file I'm using as a template to guide my schema development in MySQL (hope that's the right terminology). But, I'm kinda stuck on the issue of Access' AllowZeroLength and MySQL's NOT NULL attributes.

I'm under the impression that an AllowZeroLength setting of false would require that something be in that field. This seems to match up nicely with the NOT NULL attribute of a column in MySQL. First of all, am I correct on this?

Secondly, in Access I also see an attribute of 'Required', which is also a true/false condition, that in my mind seems redundant for a field. If an Access field has AllowZeroLength set to false and Required set to true, are they doing the same thing? It seems at first that I can accomplish the same thing in MySQL by merely setting the NOT NULL attribute on a field.

How's my thinking on this so far?