2NF There are two Definitions which is right
From: Jens Haase <jens_at_haase.to>
Date: Wed, 20 Jul 2005 23:12:07 +0200
Message-ID: <3k7t18Ft6e3bU1_at_individual.net>
I found two definitions for 2NF:
Date: Wed, 20 Jul 2005 23:12:07 +0200
Message-ID: <3k7t18Ft6e3bU1_at_individual.net>
I found two definitions for 2NF:
- A relation R(A,F) is in 2NF, when every attribute not belonging to the primary key of R is fully functionally dependent on the primary key of R
- A relation schema R is in 2NF if every nonprime attribute A in R is fully functionally dependent on the primary key of R
According to the first definition when the primary key is AB, then A->D violates 2NF, because D is not part of the primary key.
Jens Received on Wed Jul 20 2005 - 23:12:07 CEST