Ann W. Harrison wrote:

> Perhaps someone will explain what's wrong with this picture,
> but here's the script.
>
> create table test (f1 integer not null);
> alter table test add constraint dumb check (
> not exists (select x.* from test x where x.f1 = new.f1));
> commit;
>
> insert into test (f1) values (1);
>
> OK hold that thought. Now from another process:
>
> insert into test (f1) values (1);
> commit;
>
> Now back to the first process:
>
> commit;
> select * from test;
>
> F1
> ============
>
> 1
> 1

Silly question - I presume that a third attempt at the insert does
actually fail :)

--
Lester Caine
-----------------------------
L.S.Caine Electronic Services