Disappearing Tables...

[chappy]

I recently inherited a VB program that manipulates an access database. After making several minor revisions, I distributed a release for testing. Yesterday I received an email that an entire table had vanished from the source database after two users worked with my revised program. An entire table vanished! I've seen table and database corruption before, but I've never heard of a table being DELETED due to improper program code. Furthermore, I've yet to find any code in this program that deletes tables. All of the code that handles the database connection appears to be working fine, and has not been modified in any way (although, read the note below). So, aside from someone physically deleting the table from the source file, I'm kind of stumped as to what happened.

The network setup is as follows: 3 users simultaneously access a single VB executable residing on an NT 4.0 server. I do not know if this is a proper setup, however they have worked with this setup without issue for a few years now.

Any thoughts?

Note:
I've realized that the source code I've been given to modify is not the most recent source code (at least two major revisions prior to the current distribution). Unfortunately the client cannot find the most recent code and the previous programmer is MIA. So, I'm stuck trying to improve a program using code that probably isn't as sound as the current program. Great.

 

[vseale]

Disappearing Table

Without seeing the code, I can only guess. Is it possible that the missing table is a temp table the code creates? Perhaps one of the revisions causes the code the bypass the table creation step. (It doesn't help that you can't get your hands on the latest-greatest source code.) If you have a backup copy without your updates, try putting in a breakpoint (in the backup) before the table is referenced and step through it. Then do the same with your updated code and see if you can find a difference. If the source code is two versions back, then you'll probably need to recreate some other missing functionality, too. Good luck!

 

[chappy]

Thanks for the input. The missing table isn't a temporary table, which is why I'm stumped that it would simply be deleted through a program accidentally.

An aside, and I apologize if discussing business is inappropriate for this forum, however there's a lesson in it. Today, after I spent 2 1/2 hours investigating the problem, finding no logical explanation, helping my client figure out how to use his own backup software to restore backup data (what's the point of having backup software if you don't know how to use it?), and essentially setting everything straight, he mentioned that he'd still "honor" my bill for the work I had completed on the outdated code, even though he couldn't use it immediately (no fault of mine, he should have the latest source code). Of course, he would expect me to modify the latest source code when and if he ever finds it, as a part of the work for which he's already paid me. I get the wrong source code, and I'm expected to work for free as a result. Unfortunately, I did not get him to sign a contract for the work. The lesson? Get a signed contract before you start any work!

 

[Pat Hartman]

Good of him to "honor" your bill. Hopefully he'll pay it before he finds the code he really wanted you to change. Then you'll have the option of working for free or not.