For relationships in which referential integrity is enforced, you can specify whether you want Microsoft Access to automatically cascade update and cascade delete related records.
If you set these options, delete and update operations that would normally be prevented by referential integrity rules are allowed. When you delete records or change primary key values in a primary table, Microsoft Access makes necessary changes to related tables to preserve referential integrity.
If you select the Cascade Update Related Fields check box when defining a relationship, any time you change the primary key of a record in the primary table, Microsoft Access automatically updates the primary key to the new value in all related records.
If you select the Cascade Delete Related Records check box when defining a relationship, any time you delete records in the primary table, Microsoft Access automatically deletes related records in the related table.
When you delete records from a form or datasheet with the Cascade Delete Related Records check box selected, Microsoft Access warns you that related records may also be deleted. However, when you delete records using a delete query, Microsoft Access automatically deletes the records in related tables without displaying a warning.