drop table grades;
drop table students;
create table students
     (SID varchar2(6) constraint students_SID_pk primary key,
      last varchar2(12),
      first varchar2(12),
      middle char(1),
      major varchar2(4),
      sex varchar2(1),
      phone varchar2(8),
      birthday date,
      testaverage number(4,1),
      rank char(2));

create table grades
      (SID varchar2(6) constraint grades_SID_FK references students(SID),
       task varchar2(9),
       score number(4,1),
       constraint grades_pk primary Key(SID, task));

insert into students values ('123456','Smith','Robert','M','ACTG','M','555-1234','14-MAR-1980',0,'SR');
insert into students values ('123457','Jones','Frank','A','MGNT','M','555-9874','24-FEB-1982',0,'FR');

insert into grades values ('123456','Test 1',80);
insert into grades values ('123456','Test 2',70);
insert into grades values ('123456','Test 3',45);
insert into grades values ('123457','Test 1',90);
insert into grades values ('123457','Test 2',91);
insert into grades values ('123457','Test 3',86);
commit
/