Release 10.1A: OpenEdge Data Management:
SQL Development

Maintaining data integrity

Integrity constraints are application rules that the database enforces. You define integrity constraints on base tables to ensure data integrity. An integrity constraint can specify unique values for a column, validate values of a column, or provide referential integrity.

Referential integrity ensures that a specific piece of data is consistent throughout the database. For instance, a customer’s name will be spelled the same way when it appears in tables for purchase orders, merchandise shipments, and accounts receivable.

This section covers the following information:

Need for integrity constraints
Types of integrity constraints
Referential constraints