0 Replies Latest reply on Jan 10, 2005 4:12 AM by mandarjboss

    Bidirectional Self-realtionship : Is it possible?

    mandarjboss Newbie

      Hi
      I am having an Entity Bean "TestCategories". I want to have a bidirectional self-relationship for my entity bean.
      So Ideally my entity bean will be something like ....


      public abstract class QuestionCategoriesBean implements EntityBean {


      public abstract void setQuestionCategoryID(long QuestionCategoryID);

      public abstract long getQuestionCategoryID();

      public abstract String getQuestionCategoryName();

      public abstract void setQuestionCategoryName(String categoryName);

      public abstract long getParentCategoryID();

      public abstract void setParentCategoryID(long newParentCategoryID);

      public abstract java.util.Collection getSubcategory();

      public abstract void setSubcategory(java.util.Collection aSubcategory);

      public abstract QuestionCategoriesLocal getParentcategory();

      public abstract void setParentcategory(QuestionCategoriesLocal parentCategory);

      }



      In my ejb-jar.xml I have following declaration.

      <ejb-relation>
      <ejb-relation-name>QuestionCategories-QuestionCategories
      </ejb-relation-name>
      <ejb-relationship-role>
      <ejb-relationship-role-name>questioncategoriesParent</ejbrelationshiprole-name>
      Many
      <cascade-delete />
      <relationship-role-source>
      <ejb-name>QuestionCategories</ejb-name>
      </relationship-role-source>
      <cmr-field>
      <cmr-field-name>parentcategory</cmr-field-name>
      </cmr-field>
      </ejb-relationship-role>
      <ejb-relationship-role>
      <ejb-relationship-role-name>questioncategories</ejb-relationship-role-name>
      One
      <relationship-role-source>
      <ejb-name>QuestionCategories</ejb-name>
      </relationship-role-source>
      <cmr-field>
      <cmr-field-name>subcategory</cmr-field-name>
      <cmr-field-type>java.util.Collection</cmr-field-type>
      </cmr-field>
      </ejb-relationship-role>
      </ejb-relation>

      In jbosscmp-jdbc.xml I have following
      <ejb-relation>
      <ejb-relation-name>QuestionCategories-QuestionCategories</ejb-relation-name>
      <ejb-relationship-role>
      <ejb-relationship-role-name>questioncategoriesParent</ejb-relationship-role-name>
      <key-fields/>
      </ejb-relationship-role>
      <ejb-relationship-role>
      <ejb-relationship-role-name>questioncategories</ejb-relationship-role-name>
      <key-fields>
      <key-field>
      <field-name>questionCategoryID</field-name>
      <column-name>QuestionCategoryID</column-name>
      </key-field>
      </key-fields>
      </ejb-relationship-role>
      </ejb-relation>

      I am pretty confused about having bidirectional self-relationship.

      In database i have following data

      ID Name Parent
      1 Main
      2 Second 1
      3 Third 2
      4 Fourth 2

      In this case i have kept parent-id value for Main category blank.
      Whenever i am executing code to retrieve all categories my code runs in an infinite loop.

      I am not having any idea if such a kind of relationship is possible with CMR or not.

      Can anybody tell me if such a kind of relationship is possible?