many-to-many question

Ricardo · **Posted:** Mon Oct 20, 2003 10:24 am

I have a many-to-many relationship between Person and Car, where the Person_Car table contains extra columns...

I read the "Hibernate Users FAQ - Tips & Tricks"
http://www.hibernate.org/118.html#A12

Quote:

I have a many-to-many association between two tables, but the association table has some extra columns (apart from the foreign keys). What kind of mapping should I use?

Person <---> Person_Car (codPerson,codCar,date DATE) <----> Car

Code:

create table Person_Car(
codPerson NUMBER(19,0) not null, 
codCar NUMBER(19,0) not null, primary key (codPerson, codCar),
date DATE
)

and I tried to do it, but it didn't work fine...

In Person table, I put the following code:

Code:

<set name="cars" table="Person_Car">
         <key column="codAluno" />
          <composite-element class="hibernate.PersonCar">
           <property name="date" type="java.util.Date"/>
           <many-to-one name="car" class="hibernate.CarVO"/>
         </composite-element>
</set>

when I ran the "net.sf.hibernate.tool.hbm2java.CodeGenerator" to generate the classes, the class Person_Car was created...

Code:

/** @author Hibernate CodeGenerator */
public class PersonCar implements Serializable {

    /** nullable persistent field */
    private java.util.Date data;

    /** nullable persistent field */
    private hibernate.CarVO car;

I'm confused because I wanted that a PersonCar class had a field referencing Person, too.

How can I do this?

thanks

danielx510 · **Joined:** Thu Oct 16, 2003 7:22 pm **Posts:** 12

I haven't tried this myself, but i read somewhere else that you should be able to specify the parent field by using

Code:

inside of your <composite-element> tag

emmanuel · **Posted:** Wed Oct 22, 2003 4:58 am

From the DTD



<!ELEMENT parent EMPTY>
<!ATTLIST parent name CDATA #REQUIRED>

Ricardo · **Posted:** Wed Oct 22, 2003 7:14 am

Thanks guys!