Mapping Relationships

reddeagle · **Joined:** Wed Apr 27, 2005 1:30 pm **Posts:** 7

Hi Guys,

I have some beginners issues with mapping associations, i have reference material but still would like to get peoples thoughts.

I have a table Customer_Orders, that contains order informtion
I have a table Products, that lists productions available to buy.

I then have a table called orders_products which contains, an order id, a product_id and product qty.

When i create a new order all works fine except populating the orders_products table. If i remove the product qty attribute of the table i can get the table to populate
Mapping Files below.

Code:

CustomerOrders.hbm

<set
         inverse="true"
         lazy="true"
         name="ordersProductsSet"
         table="orders_products"
      >
         <key column="ORDER_ID" />
         <one-to-many class="OrdersProducts" />
      </set>

Products.hbm

Code:

<set
         inverse="true"
         lazy="true"
         name="ordersProductsSet"
      >
         <key column="PRODUCT_ID" />
         <one-to-many class="OrdersProducts" />
      </set>

OrdersProducts.hbm

Code:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
   "-//Hibernate/Hibernate Mapping DTD//EN"
   "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd" >

<hibernate-mapping package="com.egalway.estore.vo">
   <class name="OrdersProducts" table="orders_products">
      <composite-id class="OrdersProductsPK" name="id">
         <key-many-to-one
            class="Products"
            column="PRODUCT_ID"
            name="product"
          />
         <key-many-to-one
            class="CustomerOrders"
            column="ORDER_ID"
            name="order"
          />
      </composite-id>
      <property
         column="PRODUCT_QTY"
         length="11"
         name="productQty"
         not-null="false"
         type="integer"
       />
   </class>
</hibernate-mapping>

If anyone could point out how i can populate the orders_products table that would be great.

The following is what i am trying from the java side.

Code:

        OrdersProducts op = new OrdersProducts();
        op.setId(new OrdersProductsPK(p,order));
        op.setProductQty(new Integer(99));
        storeConfigService.saveObject(order);

dslevine · **Joined:** Thu May 26, 2005 12:20 am **Posts:** 72

I have something similar involving users and groups. Users are in Groups, Groups have Users, and there is a Type association so I have a UserGroupRel object in the middle that contains both references and a Type. This should work similar for you with a quantity. (My associations are all bi-directional, not sure if you need that.) Here is my xml mapping:

Code:

<class   name="User"   table="MyUser">
   <id   column="id"   name="id"   type="long"   unsaved-value="0">
      <generator   class="native"   />
   </id>
   <set name="groups" cascade="save-update">
      <key column="USER_ID" />
      <one-to-many class="UserGroupRel"/>
   </set>
</class>
<class name="UserGroupRel" table="USER_GROUP_REL">
   <id   column="id"   name="id"   type="long"   unsaved-value="0">
      <generator   class="native"   />
   </id>
   <many-to-one name="user" cascade="save-update" column="USER_ID" class="User" lazy="false" />
   <many-to-one name="group" cascade="save-update" column="GROUP_ID" class="Group" lazy="false" />
   <property name="relType" column="rel_type" type="string"/>
</class>
<class   name="Group"   table="MyGroup">
   <id   column="id"   name="id"   type="long"   unsaved-value="0">
      <generator   class="native"   />
   </id>
   <set name="users" cascade="save-update">
      <key column="GROUP_ID" />
      <one-to-many class="UserGroupRel"/>
   </set>
</class>

the USER_GROUP_REL table has 4 columns: ID, USER_ID, GROUP_ID, REL_TYPE

Good luck!