Re: 2nd Normal Form Question
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Fri, 08 Feb 2008 13:41:17 -0400
Message-ID: <47ac943e$0$4058$9a566e8b_at_news.aliant.net>
>>gamehack wrote:
>>
>>>Hi all,
>>
>>>I'm currently evaluating whether a relation is in 2NF. The relation is
>>>defined as follows:
>>><Year | Winner Name | Winner Votes | Party | Home State> in the
>>>context of an election. I've given a sample relation below.
>>>1946 | MyName | 453 | MyParty | California
>>>The primary key for this relation is 'Year'.
>>
>>>Now the question is whether this relation is in 2NF? What confuses me
>>>is that some books say the following:
>>>"Note that when a 1NF table has no composite candidate keys (candidate
>>>keys consisting of more than one attribute), the table is
>>>automatically in 2NF."
>>
>>I am not sure where you read that. It sounds like a typo or a mistake.
>>Composite keys are important at the higher normal forms.
Date: Fri, 08 Feb 2008 13:41:17 -0400
Message-ID: <47ac943e$0$4058$9a566e8b_at_news.aliant.net>
Jan Hidders wrote:
> On 8 feb, 17:39, Bob Badour <bbad..._at_pei.sympatico.ca> wrote: >
>>gamehack wrote:
>>
>>>Hi all,
>>
>>>I'm currently evaluating whether a relation is in 2NF. The relation is
>>>defined as follows:
>>><Year | Winner Name | Winner Votes | Party | Home State> in the
>>>context of an election. I've given a sample relation below.
>>>1946 | MyName | 453 | MyParty | California
>>>The primary key for this relation is 'Year'.
>>
>>>Now the question is whether this relation is in 2NF? What confuses me
>>>is that some books say the following:
>>>"Note that when a 1NF table has no composite candidate keys (candidate
>>>keys consisting of more than one attribute), the table is
>>>automatically in 2NF."
>>
>>I am not sure where you read that. It sounds like a typo or a mistake.
>>Composite keys are important at the higher normal forms.
> > Of course, but all that it says is that if you have determined all the > candidate keys and they happen all to be not-composite then a 1NF is > always also in 2NF. I'm sure you agree that this is correct. > > -- Jan Hidders
What can I say? I was tired. Your answer was so much better than mine I cancelled mine almost immediately.
Sigh. Alas, you have immortalized it. Received on Fri Feb 08 2008 - 18:41:17 CET