many-to-many the same PK

Question

How should I do if I have two tables and their primary keys have the same name like the following XML mapping file suggests?

<class name="Person" table="person">

    <id name="uid_" type="java.lang.String" column="uid">
     <generator class="native" />
    </id>

    <property name="name_" type="java.lang.String" column="pName" />
    <property name="age_" type="integer" column="age" />
    <property name="birthday_" type="date" column="birthday"/>

    <many-to-one name="school" class="School" column="schoolID" unique="false" />

    <bag name="course">
     <key column="uid" />
     <many-to-many class="Course" column="uid" />
    </bag>

  </class>

The Person and Course's primary key both named "uid". The hibernate says "Repeated column in mapping".

Answer 1

Change the name given to the column in the many to many relation.

<bag name="course">
        <key column="uid" />
        <many-to-many class="Course" column="course_uid" />
</bag>

The column in the relation mapping isn't an identifier of the course's column, it is just the name to be used in the relation table.

Answer 2

Hi,

You can map your many-to-many mapping as a composite-element as follows

Instead of

<bag name="course">
    <key column="uid"/>
    <many-to-many class="Course" column="course_uid"/>
</bag>

Try

<bag name="course">
    <key column="uid"/>
    <composite-element class="Course">
        // define properties here
    </composite-element>
</bag>

It works regardless of Course mapping file