Few confusing things about first normal form
From: <Srubys_at_gmail.com>
Date: Wed, 22 Oct 2008 11:35:25 -0700 (PDT)
Message-ID: <f8f96838-16d6-4a48-996d-6c85b79d604f_at_64g2000hsu.googlegroups.com>
greetings
Date: Wed, 22 Oct 2008 11:35:25 -0700 (PDT)
Message-ID: <f8f96838-16d6-4a48-996d-6c85b79d604f_at_64g2000hsu.googlegroups.com>
greetings
- For DB to be in 1NF there must be no multi-valued attributes, and no repeating groups. When so, data is said to be atomic. One site claims that even first name and last name must be featured in separate columns, but some other sites did put both first name and last name into a single column, and yet still claimed the table was in 1NF? So which is true?
2)
- What else do we mean by repeating groups? Just duplicative columns and multi-valued attributes, or …?
- What qualifies as a duplicative column? I imagine there are cases where it is not so obvious whether we are dealing with duplicative columns or not?
thank you Received on Wed Oct 22 2008 - 20:35:25 CEST