Task: Text to Code
Input (English): SQL: SELECT course_name FROM Courses
Feedback: Also specify that course id of course table should present only one time in student course enrolment table .
Output (English): 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(*)  =  1