Hi,
I have a
problem.
Let's say I have the
following table:
CREATE
TABLE rekl_element(id serial PRIMARY KEY,
active boolean NOT NULL DEFAULT 'y',
num int4 NOT NULL,
text varchar(10)
);
Now I want that
"num" column is "unique" but only for those columns that have active='y'. For
the columns that have active='f' I don't care if num is unique or not. I'm
asking this because num will be doubled some times.
How can I write a
constraint, trigger function... etc to check this?
Thanks in advance.
Andy.
