Powerdesigner integrity constraints (cascade deletion)

Powerdesigner integrity constraints:
Restriction: modification or deletion is not allowed. If the primary key of the primary table is modified or deleted, if the Sub-table contains a sub-record, an error message is displayed. This is the default integrity settings.

Set NULL: if the foreign key column can be empty, if you modify or delete the primary key of the primary table, set the foreign key column referenced in the subtable to null ).

Set Default: if the default value is specified, When you modify or delete the primary key of the primary table, set the foreign key referenced in the subtable to the default value ).

Cascade: when the primary key of the master table is changed to a new value, the foreign key value of the sub-table is modified accordingly. Or when the primary key record of the master table is deleted, delete the records of Foreign keys in the sub-table.

When the foreign key cascade is deleted, the operation on the primary table is associated with the child table, but the operation on the child table is not associated with the primary table.

 

The meanings of the parameters are as follows:
None: the parent table is modified, and the child table is not affected.
Restrict: Modify the parent table. If the child table exists, an error occurs.
Cascade: Modify the parent table. If the child table exists, modify the table accordingly.
Set NULL: Modify the parent table. If the child table exists, it is set to null.
Set Default: Modify the parent table. If the child table exists, set the default value accordingly.