Hibernate doubles foreign key in one-to-many

Question

I have parent entity for example named as Parent , it extends Base entity, also i have children entities named Children , and there is relation one-to-many in Parent, meaning Set<Children> , but in Children , parent is described just as Base , and therefore hibernate creates two foreign keys in children's table, but what most annoying - one of them is DELETE-CASCADE, and another is not, which cause errors when i'am trying to delete parent, how can i either have one foreign key(without strictly relation to parent as Parent in Children ), or at least fix violating key without DELETE-CASCADE?

Code (not all, just relative) :

Base.hbm.xml:

<class name="Base" table="controls">
    <id name="id">
    <subclass name="Parent" discriminator-value="Parent">
         <set name="items" cascade="save-update, delete-orphan" order-by="orderNumber asc" lazy="false" inverse="true" sort="natural">
             <key column="controlId" on-delete="cascade"/>
             <one-to-many class="children"/>
         </set>
     </subclass>
</class>

Children.hbm.xml:

<class name="controls.FAQItem" table="faq_item">
     <id name="id">
         <generator class="native"/>
      </id>
      <many-to-one name="base" column="controlId"/>
</class>

Parent.java:

public class Parent extends Base{
    private Set<Children> items;
    //getters  and setters
}

Children.class:

public class Children {
    private Base base;
    //getters and setters
}

Errors:

    Cannot delete or update a parent row: a foreign key constraint fails 
(`db_cofp`.`children`, CONSTRAINT `FK3534269CB50AD2C` FOREIGN KEY (`controlId`) 
REFERENCES `controls` (`id`))

Show create table: *just relative end

KEY `FK3534269CC41202F7` (`controlId`),
KEY `FK3534269CB50AD2C` (`controlId`),
CONSTRAINT `FK3534269CB50AD2C` FOREIGN KEY (`controlId`) REFERENCES `controls` (`id`),
CONSTRAINT `FK3534269CC41202F7` FOREIGN KEY (`controlId`) REFERENCES `controls` (`id`) ON DELETE CASCADE

Hope i showed all that matters, note thet Base and Children extends BasicEntity class with id, didn't wrote it as it just have int id and getters and setters

Answer 1

Solved by rewriting mappings to:

Base.hbm.xml:

<class name="Base" table="controls">
    <id name="id">
    <subclass name="Parent" discriminator-value="Parent">
         <set name="items" cascade="save-update, delete-orphan" order-by="orderNumber asc" lazy="false" sort="natural">
             <key column="controlId"/>
             <one-to-many class="children"/>
         </set>
     </subclass>
</class>

Children.hbm.xml:

<class name="controls.FAQItem" table="faq_item">
     <id name="id">
         <generator class="native"/>
      </id>
      <many-to-one name="base" column="controlId" class="Parent"/>
</class>