Application Relationship

Application relationships are essentially the same as Referential-Integrity, except that the data integrity is preserved by the application and not the database.

Application relationships preserve the defined relationships between tables when records are added or deleted. Application relationships are based on foreign key to primary key or unique key relationships and ensure that key values are consistent. This consistency requires that all references are to existing values, and that if a key value changes, all references to it change consistently throughout the database.

When application relationship is enforced, the application prevents users from:

• Adding records to a related table when there are not associated records in the primary table.
• Changing values in a primary table that would result in "orphaned" records in a related table.
• Deleting records from a primary table when matching related records exist.