Enforcing Referential Activity in a New Table

Enforce referential integrity in a new table.

1. Create the primary table, for example:

   CREATE TABLE DEPT(DeptNo int primary key,
   DeptName varchar(20),
   Mgr int );

2. Create the foreign table. For example, in this statement, the default role name for the specified foreign key is DEPT:

   CREATE TABLE EMPLOYEE(EmpNo int primary key,
   DeptNo int REFERENCES DEPT(DeptNo)
   ON DELETE RESTRICT,
   LastName varchar(20),
   FirstName varchar(20),
   Salary int);

3. Specify the foreign key constraint. For example:

   ALTER TABLE DEPT ADD FOREIGN KEY EMP_DEPT(DeptNo)
   REFERENCES DEPT(DeptNo);

   In this statement, the user specified role name for the same foreign key is EMP_DEPT.