| Subject | Re: [firebird-support] Nullable foreign keys |
|---|---|
| Author | Helen Borrie |
| Post date | 2004-04-29T07:58:51Z |
At 09:37 AM 29/04/2004 +0200, you wrote:
ON DELETE SET NULL
to return the dependent row to a "pool of orphans" when the master row gets
deleted.
A nullable FK can also be useful if you want to create rows that WILL be
dependent on some master row, but at insert time you don't know what that
master key is...
/heLen
>Hi,Sure you can. You can even have an RI action
>
>is it possible to have a nullable foreign key in Firebird?
>With "nullable foreign key", I mean that referential integrity
>is ensured only when the state of the field is different then
>NULL.
ON DELETE SET NULL
to return the dependent row to a "pool of orphans" when the master row gets
deleted.
A nullable FK can also be useful if you want to create rows that WILL be
dependent on some master row, but at insert time you don't know what that
master key is...
/heLen