What are all the names of teachers who have taught a course, and what were the course ids?
select name, course_id from instructor as t1 join teaches as t2 on t1.id = t2.id
Of these, which were in the Art department?
select name, course_id from instructor as t1 join teaches as t2 on t1.id = t2.id where t1.dept_name = 'Art'