Re: Does entity integrity imply entity identity?
Date: Sun, 2 Aug 2009 09:16:22 +0100
Message-ID: <pdqdnf5VYIzE1ujXnZ2dnUVZ8uqdnZ2d_at_giganews.com>
"Bob Badour" <bbadour_at_pei.sympatico.ca> wrote in message
news:4a75247b$0$23740$9a566e8b_at_news.aliant.net...
> Mr. Scott wrote:
>
>> "Bob Badour" <bbadour_at_pei.sympatico.ca> wrote in message
>> news:4a7479f3$0$23783$9a566e8b_at_news.aliant.net...
>>
>>>Mr. Scott wrote:
>>>
>>>>Since the entity integrity rule ensures that a relational table cannot
>>>>have any duplicate rows, does that imply that each row in a table maps
>>>>to a distinct entity?
>>>
>>>I am unfamiliar with an entity integrity rule. It sounds like some shit
>>>somone just made up to market ER diagrams.
>>
>> I thought Codd referred to the the entity integrity and referential
>> integrity rules as the insert-update-delete rules of the relational
>> model.
>
> Can you cite a reference for that?
>
>
The "RM/T" paper, Extending the Database Relational Model to Capture More Meaning, ACM TODS, Vol. 4, No. 4, December 1979:
-- David PortasReceived on Sun Aug 02 2009 - 10:16:22 CEST