how many total course credits does each department offer?
select sum(t1.crs_credit), t1.dept_code from course as t1 join class as t2 on t1.crs_code = t2.crs_code group by t1.dept_code
Find the department that offers the most number of credits of classes?
select * from course as t1 join class as t2 on t1.crs_code = t2.crs_code group by t1.dept_code order by sum(t1.crs_credit) desc limit 1
What is the name of that department?
select t3.dept_name from course as t1 join class as t2 on t1.crs_code = t2.crs_code join department as t3 on t1.dept_code = t3.dept_code group by t1.dept_code order by sum(t1.crs_credit) desc limit 1