> I was looking for a solution on how to write a constraint into a ' create
> table ' expression that would ensure that one ' TIME ' attribute value
> called arrival_time (declared as TIME) is allways constrained to have a
> value that ensures it is allways after another attribute value called
> departure_time (declared as TIME).
> Any know how this constraint would be written??
>
CREATE TABLE tablename (
arrival_time timestamp,
departure_time timestamp
CHECK (arrival_time < departure_time)
);