Can you list the names and ids of courses?
select course_id,title from course
I want to know the course names and the prerequisite ids.
select t1.title,t2.prereq_id from course as t1 join prereq as t2 where t1.course_id = t2.course_id
Hmm, please tell me the course ids that do not have any prerequisite.
select course_id from course except select course_id from prereq