Hi again!
The associative table has its pro and cons. As severel of you pointed out,
the use of a associative table makes the tables a lot cleaner. But as our
complex world seems to be full of multiplicity, I personally would think
twice, when the domain model is large. I did a little test to measure the
difference.
I created 100 orders with 10 orderlines each, i.e. 1000 records.
With an associative table this took: approximately 47 seconds.
Without it took: 27 seconds.
In the second test I had to make a workaround (I normalized the beans), so
the test could be misleading. But it takes me back to my original problem.
When Orion autocreates table it automatically create a associative table,
which I don't want. Naturally I want the primary key of the one side to be
placed as a foreign key in the many side. My ejb-jar.xml looks like this:
<ejb-jar>
<enterprise-beans>
<entity>
<description>Order holds a number of Orderlines.</description>
<display-name>JOrder</display-name>
<ejb-name>JOrderOne</ejb-name>
<home>OrderHome</home>
<remote>Order</remote>
<ejb-class>OrderBean</ejb-class>
<persistence-type>Container</persistence-type>
<prim-key-class>java.lang.String</prim-key-class>
<reentrant>True</reentrant>
<cmp-version>2.x</cmp-version>
<cmp-field>
<field-name>orderId</field-name>
</cmp-field>
<cmp-field>
<field-name>orderLines</field-name>
</cmp-field>
<primkey-field>orderId</primkey-field>
</entity>
<entity>
<description>Holds the ordered items of a customer</description>
<display-name>JOrderLine</display-name>
<ejb-name>JOrderLineOne</ejb-name>
<home>OrderLineHome</home>
<remote>OrderLine</remote>
<ejb-class>OrderLineBean</ejb-class>
<persistence-type>Container</persistence-type>
<prim-key-class>java.lang.String</prim-key-class>
<reentrant>True</reentrant>
<cmp-version>2.x</cmp-version>
<cmp-field>
<field-name>orderLineId</field-name>
</cmp-field>
<primkey-field>orderLineId</primkey-field>
</entity>
</enterprise-beans>
<relationships>
<ejb-relation>
<description>Order-OrderLines</description>
<ejb-relation-name>Order-Orderlines</ejb-relation-name>
<ejb-relationship-role>
<description>Order has Orderlines</description>
<ejb-relationship-role-name>Order-has-Orderlines</ejb-relationship-role-name>
<multiplicity>one</multiplicity>
<role-source>
<ejb-name>JOrderOne</ejb-name>
</role-source>
<cmr-field>
<cmr-field-name>orderLines</cmr-field-name>
<cmr-field-type>java.util.Collection</cmr-field-type>
</cmr-field>
</ejb-relationship-role>
<ejb-relationship-role>
<ejb-relationship-role-name>OrderLines-belongsto-Order</ejb-relationship-role-name>
<multiplicity>many</multiplicity>
<role-source>
<ejb-name>JOrderLineOne</ejb-name>
</role-source>
</ejb-relationship-role>
</ejb-relation>
</relationships>
<assembly-descriptor>
</assembly-descriptor>
</ejb-jar>
So, what is the solution to this problem? Is there any faults in the xml file above?
Or is there another solution to my problem?
I also read that the bug #140, maintaining a bidirectional 1-n relation, is fixed.
This is of course not a bidirectional relationship, but if Orion
could
handle this wouldn't it be naturally to suppose that it could handle unidirectional
relationships.
Regards, Theis.
