On Wednesday, March 28, 2018, JORGE MALDONADO <
jorgemal1960@gmail.com> wrote:
The table "corequisites" has data about courses that must be taken at the same time that another course.
![](/media/maillist_attaches/pgsql-novice/2018/03/28/CAKFQuwZJ5nQw9Tx0vtFnbuDPu=K4eRHhsXsTq030ioMq9qTX+Q@mail.gmail.com/image.png)
I would consider setting up corequisites as (id serial, course_group_members integer[]) with an exclusion constraint that no course_id can appear in more than one array.
David J.