How to use the relationship attributes:
  • Self Join : An entity can reference itself.
  1. Cascading : Note that when we use Cascading, we can only cascade from parent down to the child, we cannot cascade from child to the parent. This is the oposite of the OOP inheritance casting. Because in OOP, we can cast subclass to base class, but we cannot cast base class to subclass (wierd: I need to attend an OOP seminar on this). When you are using Cascading features, you can set the following Cascade Type :
  1. Cascade.CREATE # when you use this type, you will be creating the child when you are creating the parent.
  2. Cascade.DELETE # when you delete the parent, the child or Orphan will also be deleted.
  3. Cascade.UPDATE # An update to the parent, updates the child.
  4. Cascade.ALL # Signifies all Cascading type. Use this when you want all types of cascade on the parent.

The following is an example of cascading :




Last edited Feb 23, 2010 at 1:34 PM by ahmedsalako, version 12

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