What are the student IDs and middle names of the students enrolled in at most two courses?
SELECT T1.student_id ,  T2.middle_name FROM Student_Course_Enrolment AS T1 JOIN Students AS T2 ON T1.student_id  =  T2.student_id GROUP BY T1.student_id HAVING COUNT(*)  <=  2
En fazla iki kursa katılan öğrencilerin öğrenci kimlikleri ve orta isimleri nelerdir?