Re: attribute name conflicts

From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Thu, 28 Jun 2007 00:55:26 -0300
Message-ID: <4683311c$0$4329$9a566e8b@news.aliant.net>

paul c wrote:

> Bob Badour wrote:
>

>> paul c wrote:
>> ...
>> Did you perhaps mistype and mean: "Does it ever make sense within a 
>> given application (as opposed to within a given db) to have two 
>> different *attributes with identical names* that identify different 
>> types/domains?"
>>
>> If so, I would say: Yes, absolutely. While I would expect the much 
>> more common case is for similarly named attributes to have the same 
>> type, I can imagine all sorts of cases where one might use the same 
>> name for different types of things.
>>
>> Capacity might mean a volume in one case, a weight in another case and 
>> stored energy in a third case.

>
>
> Thanks, yes I did mis-type and meant it the way you put it.
>
> Regarding "capacity", I think I'd prefer for an app to use the three
> different names: "volume", "weight" and "energy". My main reason
> (psychological) would be that I find it helpful to have as much
> transparency as possible (as one might gather from reading my frequent
> mis-typings) but a technical reason might be that then I wouldn't need
> to deal with "exceptions" (I presume that an expression like "A JOIN B"
> where A and B use the "capacity" attribute name for different types
> would, in the purest sense, be considered not well-formed, ie., it would
> not be strictly logical to give a result such as "empty" or "false" for
> such an expresssion.)

Whether such a join would cause an exception is a matter of applied psychology and not theory. Received on Wed Jun 27 2007 - 22:55:26 CDT