Database: college_1
Question: Find the name of the department that offers the largest number sum of credits of all classes.
SQL: 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