0 Replies Latest reply on Apr 16, 2003 12:31 PM by sys user

    question on relationships

    sys user Master

      In jbosscmp-jdbc.xml, the <key field> is specified to indicate the primary key of the current entity used in the relationship. How does JBoss know what the foreign key is ?

      For example ... a 1 to 1 relationship between UserEJB and CustomerEJB. The primary key in UserEJB table is username and I want to link this to the email column in CustomerEJB table. So tyhe customer's email will be used as their username. In jbosscmp-jdbc.xml, I only specify username in key fields. How does JBoss know to link this username to CustomerEJB' table's email column ?

      <ejb-relation>
      <ejb-relation-name>User-Customer</ejb-relation-name>
      <foreign-key-mapping/>
      <ejb-relationship-role>
      <ejb-relationship-role-name>one-CustomerEJB@user-Has-UserEJB</ejb-relationship-role-name>
      <key-fields/>
      </ejb-relationship-role>
      <ejb-relationship-role>
      <ejb-relationship-role-name>one-UserEJB@customer-Has-CustomerEJB</ejb-relationship-role-name>
      <key-fields>
      <key-field>
      <field-name>username</field-name>
      <column-name>username</column-name>
      </key-field>
      </key-fields>
      </ejb-relationship-role>
      </ejb-relation>