消除一对多关系引用的Hibernate表中的重复条目

public class ParentEntity {
    private Set<ChildEntity> children;

    // getter and setter methods
}

public class ChildEntity {
    @ManyToOne
    private ParentEntity parent;

    // getter and setter methods
}

<hibernate-mapping>
    <class name="com.example.ParentEntity" table="parent_table">
        <id name="id" column="id">
            <generator class="native"/>
        </id>
        <set name="children" cascade="all">
            <key column="parent_id"/>
            <one-to-many class="com.example.ChildEntity"/>
        </set>
    </class>
    <class name="com.example.ChildEntity" table="child_table">
        <id name="id" column="id">
            <generator class="native"/>
        </id>
        <many-to-one name="parent" class="com.example.ParentEntity" column="parent_id"/>
    </class>
</hibernate-mapping>