EXISTS
Returns TRUE if subquery returns any rows.
sql
1SELECT * FROM courses c
2WHERE EXISTS (
3 SELECT 1 FROM students s WHERE s.course_id = c.id
4);Only courses with enrolled students.
Returns TRUE if subquery returns any rows.
1SELECT * FROM courses c
2WHERE EXISTS (
3 SELECT 1 FROM students s WHERE s.course_id = c.id
4);Only courses with enrolled students.