Referential Integrity Rule in RDBMS

Referential Integrity Rule in DBMS is based on Primary key and Foreign Key. The Rule defines that a foreign key have a matching primary key. Reference from a table to another table should be valid.

Referential Integrity Rule example −

<Employee>

<Department>

The rule states that the DEPT_ID in the Employee table has a matching valid DEPT_ID in the Department table.

To allow join, the referential integrity rule states that the Primary Key and Foreign Key have same data types.