Hi everybody,

I'm new to hibernate and already have a problem.
I have two classes say "Continent" and "Country". Country class contains one private field fo "Continent" type in order to refer to some country.

Ok what is my problem?!?

When I instantiate an country object and save it in database all goes well. For example, i have country object with name "USA" which have "America" object in continent field. So I managed saving that composite object into datbase tables. But, when I instantiate a "Canada" object and associate it with "America" continent and save class into database I HAVE TWO "America" records in COUNTRY table.

Wanted behaviour will be that Hibernate recognize that I'm refering to the same "America" object and to be smart enough to link "Canada" object with existing "America" object instead of creating new one.


I hope, this simple question will wring some credits to you

Best regards
Milicic Marko

Continent should be mapped ad many-to-one
http://www.hibernate.org/hib_docs/v3/re ... -manytoone

Actualy, I already made that kind of mapping.

<hibernate-mapping package="datamanagers">
<class name="Country" table="COUNTRY">
<id name="id" column="ID" type="java.lang.Long">
<generator class="native"/>
</id>

<property name="countryName" column="COUNTRY_NAME" type="java.lang.String"/>
<property name="countryISO" column="COUNTRY_ISO" type="java.lang.String"/>
<many-to-one name="continent" column="CONTINENT_ID" class="Continent" not-null="true"/>
</class>
</hibernate-mapping>




<hibernate-mapping package="datamanagers">
<class name="Continent" table="CONTINENT">
<id name="id" column="ID" type="java.lang.Long">
<generator class="native"/>
</id>

<property name="continentName" column="CONTINENT_NAME" type="java.lang.String"/>
</class>
</hibernate-mapping>

Please post your code between session open and close.
I suspect that you simply create a new Continent object with name “America” and put this in the Country object, that will cause creation of the new Continent record with the same name but different ID.
If you want to reuse Continent, the you should try to find existing Continent with the given name and then
country.setContinent( theExistingOne );

Thank you, you were right!