Database Design
Data and Referential Integrity
- There are at least three types of data integrity that must be designed into any database - key integrity, domain integrity and referential integrity.
- Key Integrity:
- Every table should have a primary key (which may be concatenated).
- The primary key must be controlled such that no two records in the table have the same primary key value.
- The primary key for a record must never be allowed to have a NULL value.