Re: Re: D308-E9AF-4C11 : CONFIRM from pgsql-sql (subscribe)

Поиск
Список
Период
Сортировка
От Oliver Elphick
Тема Re: Re: D308-E9AF-4C11 : CONFIRM from pgsql-sql (subscribe)
Дата
Msg-id 200107272028.f6RKSvGn003352@linda.lfix.co.uk
обсуждение исходный текст
Ответ на Re: D308-E9AF-4C11 : CONFIRM from pgsql-sql (subscribe)  (Gonzo Rock <GonzoRock@Excite.com>)
Список pgsql-general
Gonzo Rock wrote:
  >Is one recommended over the other??? Sure appreciate the commentary before I
      > get in too deep with all these tables.

The second sounds OK, but only if the chosen field is truly a candidate key.
"Customer" does not sound like one - suppose you have two 'John Smith's?
This is why most real-world applications use unique numbers or codes.
Of course you could (probably) differentiate the 'John Smith's by address,
but then the address has to be typed in as well as the name.  A code is
much easier.

It all depends on the nature of the data.

--
Oliver Elphick                                Oliver.Elphick@lfix.co.uk
Isle of Wight                              http://www.lfix.co.uk/oliver
PGP: 1024R/32B8FAA1: 97 EA 1D 47 72 3F 28 47  6B 7E 39 CC 56 E4 C1 47
GPG: 1024D/3E1D0C1C: CA12 09E0 E8D5 8870 5839  932A 614D 4C34 3E1D 0C1C
                 ========================================
     "But the wisdom that is from above is first pure, then
      peaceable, gentle, and easy to be intreated, full of
      mercy and good fruits, without partiality, and without
      hypocrisy."     James 3:17



В списке pgsql-general по дате отправления:

Предыдущее
От: "Brent R. Matzelle"
Дата:
Сообщение: PostgreSQL to Dia program
Следующее
От: Ryan Mahoney
Дата:
Сообщение: Re: RE: [SQL] Database Design Question