SELECT DISTINCT T1.course_name FROM Courses AS T1 JOIN Student_Enrolment_Courses AS T2 ON T1.course_id  =  T2.course_id
What are the names of all courses that have some students enrolled?
SELECT DISTINCT T1.course_name FROM Courses AS T1 JOIN Student_Enrolment_Courses AS T2 ON T1.course_id = T2.course_id
select distinct t1 . course_name from courses as t1 join student_enrolment_courses as t2 on t1 . course_id = t2 . course_id
What are the names of all courses that have some students enrolled ?