Should you always end mysql queries with “or die?”

Question

Example queries in some tutorials ALWAYS end with:

or die(mysql_error());  

I can see why you would would sometimes want to do this, but t

Answer 1

NO.

Avoid that at all cost!

1. It's a horrible message to show an end user
2. mysql_error may expose information you don't want to be given
3. There is no way to handle the error, i.e revert.

Imagine a database of transactions - your customer sends money, so you have to modify two tables (two queries).

First one transfers money from X to Y and succeeds. The second one has to subtract Y from X fails.

You have no way to revert the transaction and the error is not logged. Effectively making user Y happy and X left confuse where the money went...

Use a sensible error handling for queries - either make a class that will handle that for you or use ORM.