cascade module

Cascade constraints can be aplied to fields or to a table. Types of cascade:

• allow-delete is default and removes the link before deleting the record
• cascade-keep for a field means that if the linked record is going to be deleted, then this needs to be prevented
• cascade-keep for a table means that if a record from that table is going to be deleted and is used in some other tables, then this needs to be prevented. This can be override by specifying cascade-delete or cascade-allow for a field.
• cascade-delete for a fields means that the linked record is going to be deleted also. If that is not possible, then the delete fails