Application Relationships

Application relationships are defined within the File-AID/EX Application Relationship Editor to preserve relationships between tables when records are entered or deleted. The 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 be assigned to valid values and, if a key value changes, all references to it change consistently throughout the database.

The concept of application relationships is similar to that of referential integrity except that data integrity is preserved by the application not the database.

When an application relationship is enforced, it ensures the following:

• All records added to related tables contain a reference to an associated record in the primary table.
• Before changing values in a primary table, the user must make any necessary changes to related tables.
• Before deleting records from a primary table, the corresponding records are removed from any related tables.