The deployment descriptor provides the following information about the abstract persistence schemas of entity beans and their container-managed relationships:
An ejb-name element for each entity bean. The ejb-name MUST be a valid Java identifier and MUST be UNIQUE within the ejb-jar file.
An abstract-schema-name element for each entity bean. The abstract-schema-name MUST be a valid Java identifier and MUST be unique within the ejb-jar file. The abstract-schema-name element is used in the specification of EJB QL queries.
A set of ejb-relation elements, each of which contains a PAIR of ejb-relationship-role elements to describe the two roles in the relationship.
Each ejb-relationship-role element describes a relationship role: its name, its multiplicity within a relation, and its navigability. It specifies the name of the cmr-field that is used from the perspective of the relationship participant. The cmr-field-type element MUST be specified if the type of the cmr-field is java.util.Collection or java.util.Set. Each relationship role refers to an entity bean by means of an ejb-name element contained in the relationship-role-source element.
<ejb-jar> ... <enterprise-beans> ... </enterprise-beans> <relationships> <!-- ONE-TO-MANY: Order LineItem --> <ejb-relation> <ejb-relation-name>Order-LineItem</ejb-relation-name> <ejb-relationship-role> <ejb-relationship-role-name> order-has-lineitems </ejb-relationship-role-name> <multiplicity>One</multiplicity> <relationship-role-source> <ejb-name>OrderEJB</ejb-name> </relationship-role-source> <cmr-field> <cmr-field-name>lineItems</cmr-field-name> <cmr-field-type>java.util.Collection</cmr-field-type> </cmr-field> </ejb-relationship-role> <ejb-relationship-role> <ejb-relationship-role-name> lineitem-belongsto-order </ejb-relationship-role-name> <multiplicity>Many</multiplicity> <cascade-delete/> <relationship-role-source> <ejb-name>LineItemEJB</ejb-name> </relationship-role-source> <cmr-field> <cmr-field-name>order</cmr-field-name> </cmr-field> </ejb-relationship-role> </ejb-relation> <!-- ONE-TO-MANY unidirectional relationship: Product is not aware of its relationship with LineItem --> <ejb-relation> <ejb-relation-name>Product-LineItem</ejb-relation-name> <ejb-relationship-role> <ejb-relationship-role-name> product-has-lineitems </ejb-relationship-role-name> <multiplicity>One</multiplicity> <relationship-role-source> <ejb-name>ProductEJB</ejb-name> </relationship-role-source> <!-- since Product does not know about LineItem there is no cmr field in Product for accessing Lineitem --> </ejb-relationship-role> <ejb-relationship-role> <ejb-relationship-role-name> lineitem-for-product </ejb-relationship-role-name> <multiplicity>Many</multiplicity> <relationship-role-source> <ejb-name>LineItemEJB</ejb-name> </relationship-role-source> <cmr-field> <cmr-field-name>product</cmr-field-name> </cmr-field> </ejb-relationship-role> </ejb-relation> <!-- ONE-TO-MANY: Order Customer: --> <ejb-relation> <ejb-relation-name>Order-Customer</ejb-relation-name> <ejb-relationship-role> <ejb-relationship-role-name> customer-has-orders </ejb-relationship-role-name> <multiplicity>One</multiplicity> <relationship-role-source> <ejb-name>CustomerEJB</ejb-name> </relationship-role-source> <cmr-field> <cmr-field-name>orders</cmr-field-name> <cmr-field-type> java.util.Collection </cmr-field-type> </cmr-field> </ejb-relationship-role> <ejb-relationship-role> <ejb-relationship-role-name> order-belongsto-customer </ejb-relationship-role-name> <multiplicity>Many</multiplicity> <relationship-role-source> <ejb-name>OrderEJB</ejb-name> </relationship-role-source> <cmr-field> <cmr-field-name>customer</cmr-field-name> </cmr-field> </ejb-relationship-role> </ejb-relation> </relationships> ... </ejb-jar>