please give the correct answer

4. A university database schema is given below: classroom(building, room_number, capacity) department(dept_name, building, budget) course(coursesid, title, dept_name, credits) instructor(ID), name, deptname, salary) section(course_id, secid, semester, year, building, room_number, timesslot_id) teaches ID, courseid, secid, semester, year ) student(ID, name, dept_name, tot_cred) takes (ID, course jid, sec jid, semester, year, grade) advisor (SJD,i in ) timesslot(time-slotid, day, start_time, end_time) prereq (courseid, prerequid) Find all keys and write the DDL for the above schema. Write SQL command for class routine. 4. A university database schema is given below: classroom(building, room_number, capacity) department(dept_name, building, budget) course(coursesid, title, dept_name, credits) instructor(ID), name, deptname, salary) section(course_id, secid, semester, year, building, room_number, timesslot_id) teaches ID, courseid, secid, semester, year ) student(ID, name, dept_name, tot_cred) takes (ID, course jid, sec jid, semester, year, grade) advisor (SJD,i in ) timesslot(time-slotid, day, start_time, end_time) prereq (courseid, prerequid) Find all keys and write the DDL for the above schema. Write SQL command for class routine