Bad cascade

[Mike Okri]

I have a many-to-many mapping between student and course and I have cascade="all" on the students-to-courses mapping as shown below. When I delete a student, hibernate cascades the delete to all of the students courses. My problem is that some of these deleted courses are also shared by other students. How do I ensure that deleting student_A will delete only courses that belong only to student_A and not courses that are shared with student_B.

<hibernate-mapping>
    <class name="com.vaannila.student.Student" table="STUDENT">
        <id name="studentId" type="long" column="STUDENT_ID">
            <generator class="native" />
        </id>
        <property name="studentName" type="string" length="100" not-null="true" column="STUDENT_NAME" />
        <set name="courses" table="STUDENT_COURSE" cascade="all" >
            <key column="STUDENT_ID" />
            <many-to-many column="COURSE_ID"  class="com.vaannila.student.Course" />
        </set>
    </class>
</hibernate-mapping>

[Ogeh Ikem]

cascade="all", cascade="delete", and cascade="all-delete-orphans" should be avoided when dealing with many-to-many associations, or else, problems like this will arise.