What is the name and address of the department with the most students?
SELECT T2.dept_name ,  T2.dept_address FROM student AS T1 JOIN department AS T2 ON T1.dept_code  =  T2.dept_code GROUP BY T1.dept_code ORDER BY count(*) DESC LIMIT 1
department with the most students refers to MAX(COUNT(student_id)); name and address of the department refers to dept_name and dept_address; joining condition is based on dept_code;