How to check for success on Active Record's Class Operations

[eluser]Daniel Peraza[/eluser]
Hi there!.

I'm beginning with CI, although I already have some PHP experience. I have read the user guide but there is one thing unclear to me: how should I check for unsuccessful model operations?, let's say that I try to delete a not existent record or that my query has syntax errors, then how should I check the Active Record Class method's return values within my controller?

I'm a little confuse since some methods of the ARC return other ARC objects, which in turn, is what permits method chaining to my understand.