Question: How many students and instructors are in each department?
SQL: SELECT count(DISTINCT T2.id) ,  count(DISTINCT T3.id) ,  T3.dept_name FROM department AS T1 JOIN student AS T2 ON T1.dept_name  =  T2.dept_name JOIN instructor AS T3 ON T1.dept_name  =  T3.dept_name GROUP BY T3.dept_name