**All three table contains 'semester' and 'department' column**

```sql
SELECT DISTINCT 
  test_name,
  fname,
  lname,
  rno 
FROM exam_attempted_list
INNER JOIN stud_test ON
  exam_attempted_list.student_id = stud_test.student_id
INNER JOIN stud_reg ON
  exam_attempted_list.student_id = stud_reg.student_id WHERE semester='2nd' AND department='cse'

```