I have two tables like following:
create table attendancereport (
id serial unique not null,
staff_id integer not null references staff(id),
schoolyear varchar not null references schoolyear(year),
students_id integer not null references students(id)
);
// schoolyear.year in format "2003 - 2004".
Create table attendancerecords (
attendancereport_id integer not null references attendancereport(id),
schoolday integer not null references schooldays(day),
attended bool not null
);
// schoolday.day in formation YYYYMMDD as in 200301222 for dec 22, 2003.
What I'm looking for is a way to create a unique( ) across tables via the
foriegn key, something like
Alter table attendancerecords
ADD unique (schoolday, attendancereport.students_id);
so that for a given student, there can be one and only one of any particular
schoolday. Can this be done with constraints?
-Ben
--
"I kept looking around for somebody to solve the problem.
Then I realized I am somebody"
-Anonymous
