Three tables courses,registration,students columns in students firstname,lastname,studentid,major,admitdate,graddate,gender,dob columns in registration courseid,studentid columns in courses coursenumber,coursename,credits select statement I need to modify select lastname as 'Last Name',sum(credits) as 'Credits Registered For' from students as s inner join registration as r on s.studentid = r.studentid inner join courses as c on c.coursenumber = c.courseid group by last name; the question on the lab is... Modify the previous query to show all students, even if they have not registered for a class. You should have 14 rows. Students who are not registered will show NULL in output. I know this requires outer join of some sort but I'm not fully grasping these joins i've read multiple posts on here and other sites but can't seem figure it out.