In addition to what the anonymous monk has to say (I'll admit it, it was me, not logged in), take a look at the code that creates the DB handle in that example, where RaiseError is set to 1 (i.e. true). That means the die is automatically called on a DB error, so it's functionally equivalent to the code "AM" provided.

HTH

I mistrust all systematizers and avoid them. The will to a system shows a lack of integrity -- F. Nietzsche