>>Back to my example. I'm not entirely sure what this trigger is doing.
>>
>>

>>CREATE TRIGGER InsertPublication 
>>ON Publications 
>>AFTER INSERT 
>>AS 
>>BEGIN 
>>	UPDATE Books 
>>	SET NumPublications = NumPublications + 1
>>               FROM Books, inserted 
>>	       WHERE Books.ISBN = inserted.ISBN 
>>END
>>

>>
>
>For each inserted book information into the Publications table this trigger also updates Books table and increments NumPublications field.
>
>In another words, say, you inserted two records into Publications table with the same ISBN, then Books table would have NumPublications field incremented by 2 for this Book.

Thanks All!