delete from enrollment
delete from section
delete from officehour
delete from course
delete from professor
delete from student

insert into professor values (1, 'Mark', 'DC3346', 'CS')
insert into professor values (2, 'Sue',  'MC1234', 'CO')
insert into professor values (3, 'Jane', 'DC1234', 'CS')
insert into professor values (4, 'Bob',  'MC3456', 'PM')

insert into student values (1, 'Mary', 3)
insert into student values (2, 'Fred', 2)
insert into student values (3, 'Bob', 4)

insert into course values ('CS348', 'Intro to Databases')
insert into course values ('CS234', 'Minor DS')
insert into course values ('CS245', 'Logic')

insert into section values ('CS348', 'F2018', 1, 1)
insert into section values ('CS348', 'F2018', 2, 1)
insert into section values ('CS348', 'S2020', 1, 1)
insert into section values ('CS348', 'S2020', 2, 4)
insert into section values ('CS245', 'F2018', 1, 4)
insert into section values ('CS245', 'S2018', 1, 4)
insert into section values ('CS245', 'W2018', 1, 4)
insert into section values ('CS245', 'F2019', 1, 1)
insert into section values ('CS245', 'F2019', 2, 2)
insert into section values ('CS234', 'S2020', 1, 2)
insert into section values ('CS234', 'S2020', 2, 3)

insert into officehour values ('CS348', 'S2020', 1, 'Tuesday', '09:00')
insert into officehour values ('CS348', 'F2018', 1, 'Friday', '14:30')

insert into enrollment values (1, 'CS245', 'F2018', 1, 57)
insert into enrollment values (2, 'CS245', 'S2018', 1, 56)
insert into enrollment values (3, 'CS245', 'W2018', 1, 58)
insert into enrollment values (1, 'CS348', 'F2018', 1, 55)
insert into enrollment values (1, 'CS348', 'F2018', 2, 65)
insert into enrollment values (3, 'CS348', 'F2018', 1, 95)
insert into enrollment values (2, 'CS348', 'S2020', 1, null)
insert into enrollment values (2, 'CS234', 'S2020', 2, null)
insert into enrollment values (2, 'CS245', 'F2019', 1, 30)
insert into enrollment values (3, 'CS245', 'F2019', 2, 95)