A cascading operation indicates how changes to the persistent object affect associated objects when an object is persisted. For instance, if the removed object is associated with other objects, what should happen to the others when the removed object is erased from the database?
I'll explain with an example. Consider the
Teacher class in the educational system application. Suppose that each teacher is associated with a single course, meaning the
Teacher class has a property of type
Course. If we use the
COURSE tables, respectively, to store the
Course objects in the database, then corresponding to each
Teacher object is a single
Course object, and corresponding to each row in the
TEACHER table is a ...