Re: circular relationships ok?
Date: Fri, 03 Mar 2006 14:19:04 -0800
Message-ID: <61gh02d8g5jvvbfueksckqnmkgf8lnueeo_at_4ax.com>
On 3 Mar 2006 12:50:31 -0800, "Marshall Spight"
<marshall.spight_at_gmail.com> wrote:
>Gene Wirchenko wrote:
>> On 2 Mar 2006 18:51:01 -0800, "Marshall Spight"
>> >
>> >I'm not getting it. If we're talking about husband and wife in
>> >a context in which there is exactly one-for-one always,
>> >then we are talking about a table of married people. In
>>
>> No. The husband and wife exist as separate entities and may be
>> referred to individually. There may *also* be a table reflecting the
>> marriages.
>>
>> >which case, why wouldn't I have HusbandBirthday, WifeBirthday,
>> >etc.? In fact, I don't really see how the particular domain
>>
>> Because you probably want the birthdate of the person regardless
>> of the role the person has in a marriage. People who are not married
>> have birthdates, too.
>
>This line of reasoning doesn't work for me at all. The question
>was whether to put data items which are exactly-one-to-exactly-one
>in the same table; it is not relevant to argue that you might not
>want to do so because they might not be exactly-one-to-exactly-one.
If the persons table has information on both married and
unmarried persons and there is a table about marriages, where do you
think the brithdates should go?
To me, putting it in the marriages table is ludicrous. An
unmarried person has a birthdate.
Sincerely,
Gene Wirchenko Received on Fri Mar 03 2006 - 23:19:04 CET