How many students are enrolled in "AI"?
select count(*) from courses as t1 join student_course_enrolment as t2 on t1.course_id = t2.course_id where t1.course_name = "AI"
Okay. Tell me the names of the courses that have student enrollment bigger than 5?
select t1.course_name from courses as t1 join student_course_enrolment as t2 on t1.course_id = t2.course_id group by t1.course_name having count(*) > 5
What are the descriptions and names of the courses that have student enrollment bigger than 2?
select t1.course_description, t1.course_name from courses as t1 join student_course_enrolment as t2 on t1.course_id = t2.course_id group by t1.course_name having count(*) > 2