Database Normalisation Questions
Cascading updates and cascading deletes are both features in database normalization that help maintain data integrity and consistency.
Cascading updates refer to the automatic propagation of changes made to a primary key value to all related foreign key values in other tables. This means that if a primary key value is updated, all corresponding foreign key values in other tables will also be updated to reflect the new value. This ensures that the relationships between tables remain intact and consistent.
On the other hand, cascading deletes refer to the automatic deletion of related records in other tables when a record in the primary table is deleted. This means that if a record is deleted from the primary table, all related records in other tables that have a foreign key referencing the deleted record will also be deleted. This helps maintain referential integrity and prevents orphaned records in the database.
In summary, the main difference between cascading updates and cascading deletes is that cascading updates propagate changes to related records, while cascading deletes automatically delete related records when a primary record is deleted.