On Tue, 26 Oct 2004, Mike Mascari wrote:
> I'd like to ensure that the creation of a department also implies the
> creation of two to eight projects; no more, no less:
>
> CREATE TABLE departments (
> department text primary key not null
> );
>
> CREATE TABLE projects (
> project text primary key not null,
> department text not null
> references departments(department)
> on delete cascade
> on update cascade
> );
>
> So it'd be nice to have an INSERT trigger that's fired on departments at
> the end of the transaction to ensure that between two and eight projects
> exist for the newly created department.
>
> Is there no way to achieve the above stated goal in the server? Must I
> rely on the application to enforce consistency?
Well. It's not exactly meant to be a user facing feature, but check out
CREATE CONSTRAINT TRIGGER.