Find the all info about the accounting department.
select * from department where dept_name = 'Accounting'
Which classes are taught the department?
select * from class as t1 join course as t2 on t1.crs_code = t2.crs_code join department as t3 on t3.dept_code = t2.dept_code where t3.dept_name = 'Accounting'
How many students are enrolled in those classes?
select count(*) from class as t1 join enroll as t2 on t1.class_code = t2.class_code join course as t3 on t1.crs_code = t3.crs_code join department as t4 on t3.dept_code = t4.dept_code where t4.dept_name = 'Accounting'