Re: Multiple table relationship constraints

Поиск
Список
Период
Сортировка
От Rick Genter
Тема Re: Multiple table relationship constraints
Дата
Msg-id BANLkTinzH+WjR+e68_8rm0Omee=L+0cUxQ@mail.gmail.com
обсуждение исходный текст
Ответ на Re: Multiple table relationship constraints  (Jack Christensen <jackc@hylesanderson.edu>)
Ответы Re: Multiple table relationship constraints
Список pgsql-general
Дерево обсуждения
On Thu, May 5, 2011 at 3:50 PM, Jack Christensen <jackc@hylesanderson.edu> wrote:
The trick is there are additional attributes of actions and achievements such as a category that must match for the link to be valid. These attributes are not part of the primary key of either record and can and do change.

So your data is denormalized? (The "category" appears in 2 tables?) Don't do that. Create a view that joins your two tables together instead if you need a single entity that contains data from multiple sources. Then you won't have any of the data integrity issues you're worried about.

--
Rick Genter
rick.genter@gmail.com

В списке pgsql-general по дате отправления:

Чтобы сделать работу с сайтом удобнее, мы используем cookie и аналитический сервис «Яндекс.Метрика». Продолжая пользоваться сайтом, вы соглашаетесь с их использованием.