The CASCADE option is part of the Relational Model, and it answers the question what should happen if you attempt to delete or alter one of the fields you used to establish a relation in the Database Options / Relations dialog. For example, what should happen if you delete a supplier for which there exists at least one matching shipment.
The options are, either CASCADES, i.e. the delete operation “cascades” to delete those matching shipments also; or RESTRICTED, i.e. the delete operation is “restricted” to the case where there are no matching shipments, and is rejected otherwise.
In the Relational Model a relationship is established between a primary key and a foreign key. They have a third option: NULLIFY. In that case the foreign key is set to null (representing missing information) in all matching shipments. The supplier is then deleted.
A similar rule is needed for an attempt to update a primary key. Again, CASCADES updates then also the foreign key. Or the rule may restrict update to those cases where there are no matching foreign keys.
I had expected this option to be somewhere in the Database Options / Relations dialog, because the idea in the Relational Model is that the DBMS, i.e. the system, takes care of these cases, and not the user. It is an important feature to maintain data integrity. It may be in Panorama, just in a different way. Therefore my question.
Thanks
Helmut