zKsYNRRH

1drop table if exists students;
2create table students (                                           
3   first varchar not null,                                                          
4   last varchar not null,                                                           
5   id int not null,                                                                
6   primary key (id));
7
8drop table if exists courses;
9create table courses (                                          
10   coursenum varchar not null,                                                     
11   title varchar not null,                                                         
12   description varchar not null,                                                   
13   primary key (coursenum));     
14
15drop table if exists enrollments;
16create table enrollments (                                      
17   id int not null,                                                                
18   coursenum varchar not null,                                                     
19   semester varchar not null,                                                      
20   year int not null,                                                              
21   primary key (id,coursenum,semester,year),                                       
22   foreign key (id) references students(id),                                       
23   foreign key (coursenum) references courses(coursenum)); 
24
25insert into students values ('Harry', 'Potter', 1);
26insert into students values ('Hermione', 'Granger', 2);
27insert into students values ('Ron', 'Weasley', 3);
28
29insert into courses values ('P140', 'Intro to Potions', 'A course in potions.');
30insert into courses values ('DA101', 'Intro to Dark Arts', 'A course in Dark Arts.');
31insert into courses values ('HB100', 'Intro to Herbology', 'A course in Herbology.');
32
33insert into enrollments values (1, 'DA101', 'Fall', 2010);
34insert into enrollments values (1, 'P140', 'Fall', 2010); 
35insert into enrollments values (2, 'P140', 'Fall', 2011);
36insert into enrollments values (3, 'P140', 'Fall', 2011); 
37insert into enrollments values (3, 'P140', 'Fall', 2012);