Re: Few confusing things about first normal form
Date: Thu, 23 Oct 2008 13:49:37 GMT
<Srubys_at_gmail.com> wrote in message
>1) 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?
First name and last name do not have the same semantics. A person whose name is "SAMUEL CHRISTOPHER" does not have the same name as a person whose name is "CHRISTOPHER SAMUEL". Since the attributes are different attributes, putting them in spearate columns does not cause an implicit repeating group.
If you go across cultures, the semantics can become obscured. For example, the family name of "MAO ZEDONG" is "MAO". Many Europeans do not realize this. Received on Thu Oct 23 2008 - 15:49:37 CEST