Base question

krasig · **Joined:** Fri Feb 10, 2006 8:33 am **Posts:** 32

Hi GURUS.
I have base question.

There is 2 classes

Code:

<hibernate-mapping>
        <class name="model.Classification" table="classification">
                <id name="id" column="id">
                        
                        <generator class="sequence">
                              <param name="sequence">test</param>
                        </generator>
                </id>
                 <set name="ObjectRelation_test" lazy="true" inverse="true" cascade="all-delete-orphan">
                    <key column="id_object1"/>
                    
                    <one-to-many class="model.ObjectRelation_test" />
                </set>

  </class>
</hibernate-mapping>

and 

<hibernate-mapping>
        <class name="model.ObjectRelation_test" table="object_relations" where="code_object1=1 and code_object2=1">
                <id name="id" column="id">
                   
                        <generator class="sequence">
                                <param name="sequence">test</param>
                        </generator>
                </id>
                
                <property name="code_object1" not-null="true"/>
                <property name="role"/>
                
        </class>
</hibernate-mapping>

And there is:

Code:

Classification cls=(Classification)session.load(Classification.class,new Long(1));

Set mySet=cls.getObjectRelation_test();

ObjectRelation_test obr=new ObjectRelation_test();

obr.setRole(new Long(22));

mySet.add(obr);

So tell me how to set automaticly value ot

Code:

code_object1

in

Code:

ObjectRelation_test

to be equal of

Code:

Classification.id

In this moment when create commit, there is

Code:

Cannot insert a null into column (object_relations.id_object1)

LaLiLuna · **Posted:** Fri Feb 10, 2006 10:53 am

Hello,

this is a simple 1:n relation. Have a look in the hibernate reference. Your second mapping is not correct.

Sebastian

krasig · **Joined:** Fri Feb 10, 2006 8:33 am **Posts:** 32

Hello LaliLuna

Yes I know that. I looked in refference, Hibernate in Action and in Hibernate Quickly and can't find solution. I don't have to create one-to-many and many-to-one relation . just one-to-many.

Tell me please how to create this.

Regards

LaLiLuna wrote:

Hello,

this is a simple 1:n relation. Have a look in the hibernate reference. Your second mapping is not correct.

Sebastian

LaLiLuna · **Posted:** Fri Feb 10, 2006 11:10 am

Then you must not use
<property name="code_object1" not-null="true"/>

just delete it.

Sebastian

krasig · **Joined:** Fri Feb 10, 2006 8:33 am **Posts:** 32

There is small mistake
<hibernate-mapping>
<class name="model.Classification" table="classification">
<id name="id" column="id">

<generator class="sequence">
<param name="sequence">test</param>
</generator>
</id>
<set name="ObjectRelation_test" lazy="true" inverse="true" cascade="all-delete-orphan">
<key column="id_object1"/>

<one-to-many class="model.ObjectRelation_test" />
</set>

</class>
</hibernate-mapping>

and

<hibernate-mapping>
<class name="model.ObjectRelation_test" table="object_relations" where="code_object1=1 and code_object2=1">
<id name="id" column="id">

<generator class="sequence">
<param name="sequence">test</param>
</generator>
</id>

<property name="id_object1" not-null="true"/>
not <property name="code_object1" not-null="true"/>
<property name="role"/>

</class>
</hibernate-mapping>

an if delete <property name="id_object1" not-null="true"/>
result is:
Cannot insert a null into column (object_relations.id_object1)

LaLiLuna · **Posted:** Fri Feb 10, 2006 12:23 pm

krasig
you must decide if you want to have a bi-directional relation
1:n + n:1 or uni-directional.
Either you omit the tag as I told you and have a 1:n
or you must correct it as explained in 1:n+n:1 relation in the reference.

I would appreciate if you rate, when this solved your problem

Sebastian

krasig · **Joined:** Fri Feb 10, 2006 8:33 am **Posts:** 32

Hi LaliLuna

I have to create 1:n uni-directional relation.
But when save Parent objectm, must automaticly optain ID to save in Chaild table.
And tell me how to create this simple operation

P.S please excuse me for bad language

LaLiLuna wrote:

krasig
you must decide if you want to have a bi-directional relation
1:n + n:1 or uni-directional.
Either you omit the tag as I told you and have a 1:n
or you must correct it as explained in 1:n+n:1 relation in the reference.

I would appreciate if you rate, when this solved your problem

Sebastian

LaLiLuna · **Posted:** Fri Feb 10, 2006 12:40 pm

Hopefully I will get a rating ;-)

first:
no inverse="true" and not null as well
just

Code:

                 <set name="ObjectRelation_test" lazy="true"  cascade="all-delete-orphan">
                    <key column="id_object1"  not-null="true"/>
                   
                    <one-to-many class="model.ObjectRelation_test" />
                </set> 

Pleeeaaaaase delete

Code:

then your code will work. Do not call session.save(myObjectRelation_test);
just add it to the collection of your classification and commit the transaction.

krasig · **Joined:** Fri Feb 10, 2006 8:33 am **Posts:** 32

Yeaaaaaaaaaaaa.That was a great.
Many thanks LaLiLuna

God bless you.