Re: null foreign key column
От | Bruno Wolff III |
---|---|
Тема | Re: null foreign key column |
Дата | |
Msg-id | 20030212204109.GB30483@wolff.to обсуждение исходный текст |
Ответ на | null foreign key column ("Arunachalam Jaisankar" <jsankar@xtra.co.nz>) |
Список | pgsql-sql |
On Tue, Feb 11, 2003 at 16:55:28 +1300, Arunachalam Jaisankar <jsankar@xtra.co.nz> wrote: > Hi all, > > I would like to have a foreign key column in my table which allows null value also. > But the below create table sql command doesn't accept null value for person_id. > How to do in postgres? > > create table event > ( > event_id serial not null, > event_description char(255) , > person_id serial , > primary key (event_id), > foreign key (person_id) > references person (person_id) > ); I don't think you want to use serial type for a value that references another table. Use integer instead. Serial also implies not null which is why you couldn't stick null values into that field.
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