I just had a problem today that made me want to remind all of my Access developers to always check for both NULL values and EMPTY STRINGS.

I had a situation today where a customer wasn't seeing one of his courses in the course listing for his account. It was THERE. It was on his account in my database, but it wasn't showing up online.

I'm not going to go into ALL of the details, but essentially there was a lookup in the ASP VBScript in my web page that was checking for an empty string:

If CourseName="" then ' do some stuff

Well it turns out that in a RARE instance the database actually returned a NULL value instead of an empty string. So what I needed to do was check for both:

If CourseName="" OR IsNull(CourseName) then ' do some stuff

I added that and it worked immediately. Sometimes this stuff gets even the most advanced developers. It was probably laziness on my part when I was building the online account system in the first place... then again I built it 6 or 7 years ago and I've learned a LOT since then (yes, it needs to be rebuilt).

But... I just figured I'd share this with you. Even I run into bugs in my programming... sometimes. :)

I talk more about NULL values here.