Mega Code Archive
Referential Constraints
<![CDATA[
4>
5> CREATE TABLE department(
6> dept_no CHAR(4) NOT NULL,
7> dept_name CHAR(25) NOT NULL,
8> location CHAR(30) NULL,
9> CONSTRAINT prim_dept PRIMARY KEY (dept_no))
10> GO
1>
2> CREATE TABLE employee (
3> emp_no INTEGER NOT NULL,
4> emp_fname CHAR(20) NOT NULL,
5> emp_lname CHAR(20) NOT NULL,
6> dept_no CHAR(4) NULL,
7> CONSTRAINT prim_emp PRIMARY KEY (emp_no),
8> CONSTRAINT foreign_emp FOREIGN KEY(dept_no) REFERENCES
9> department(dept_no))
10> GO
1>
2> CREATE TABLE project (project_no CHAR(4) NOT NULL,
3> project_name CHAR(15) NOT NULL,
4> budget FLOAT NULL,
5> CONSTRAINT prim_proj PRIMARY KEY (project_no))
6> GO
1>
2> CREATE TABLE myProject (emp_no INTEGER NOT NULL,
3> project_no CHAR(4) NOT NULL,
4> job CHAR (15) NULL,
5> enter_date DATETIME NULL,
6> CONSTRAINT prim_works PRIMARY KEY(emp_no, project_no),
7> CONSTRAINT foreign1_works FOREIGN KEY(emp_no) REFERENCES
8> employee(emp_no),
9> CONSTRAINT foreign2_works FOREIGN KEY(project_no) REFERENCES
10> project(project_no))
11> GO
1>
2> drop table myProject;
3> GO
1>
2> drop table project;
3> GO
1> drop table employee;
2> GO
1> drop table department;
2> GO
]]>