Re: Database design
From: Alexandr Savinov <spam_at_conceptoriented.com>
Date: Wed, 22 Feb 2006 10:49:12 +0100
Message-ID: <43fc33a1$1_at_news.fhg.de>
>
>
>
> As I understood it, the entity is each row in a relation, each entity
> consisting of various attributes, which alternately are termed,
> tuples. And each entity is supposed to be of 'like kind'.
> Unfortunately, based on previous messages, no one really seems to know
> what that is, or whether such 'like kinds' are even important.
Date: Wed, 22 Feb 2006 10:49:12 +0100
Message-ID: <43fc33a1$1_at_news.fhg.de>
Mark Johnson schrieb:
> Alexandr Savinov <spam_at_conceptoriented.com> wrote:
>
>> JOG schrieb: >>> Mark Johnson wrote: >>>> "x" <x_at_not-exists.org> wrote: >>>>> "Roy Hann" <specially_at_processed.almost.meat> wrote in message >>>>> news:3--dnYnbkrrCfmTenZ2dnUVZ8qadnZ2d_at_pipex.net... >>>>>> "x" <x_at_not-exists.org> wrote in message news:dtcjfn$f87$1_at_nntp.aioe.org... >>>>> Well, the slippery part is not that amusing after a while. >>>>>> I am more inclined to read it as just the usual witless gaff of noticing >>>>>> that the bounding box of a printed representation of a table has length >>>>>> width and leaping to the conclusion that a table is therefore >>>>>> two-dimensional; planar: flat. >>>> Then I certainly stand to be corrected. I thought the relation was >>>> thought to be essentially an unordered set or list of entities, and >>>> nothing more.
>
>>> A tuple does not equate to an entity, in fact far from it.
>
>> So what is then an entity?
>
> As I understood it, the entity is each row in a relation, each entity
> consisting of various attributes, which alternately are termed,
> tuples. And each entity is supposed to be of 'like kind'.
> Unfortunately, based on previous messages, no one really seems to know
> what that is, or whether such 'like kinds' are even important.
Is it really necessary for an entity to be inside a relation?
-- http://conceptoriented.comReceived on Wed Feb 22 2006 - 10:49:12 CET