find the student id and personal name of the student whose course id is 2
select t1.student_id, t2.personal_name from student_course_enrolment as t1 join students as t2 on t1.student_id = t2.student_id where t1.course_id = '2'
show the date of registration for the student id 1
select date_of_registration from students where student_id = '1'
show the login name and password for registration id  2
select t1.login_name, t1.password from students as t1 join student_course_enrolment as t2 on t2.student_id = t1.student_id where registration_id = 2