A university database schema is given :

Find all keys and write the DDL for the above schema. Write SQL command for class routine.

classroom (building, room_number, capacity) department(dept_name, building, budget) course (courseid, title, dept_name, credits) instructor(ID name, dept_name, salary) section(course_id, secid, semester, year, building, room_number, time_slot_id) teaches (ID, courseid, secid, semester, year) student(ID, name, dept_name, tot_cred) takes (ID, course id, sec id, semester, year, grade) advisor(s_ID, iJD) time_slot(time_slot_id, day, start_time, end_time) prereq(course_id, prereq_id )