How to insert an object with associations in one transaction

snirf · **Posted:** Wed May 02, 2007 6:48 am

Hey there,
What I am trying to do is inserting an object plus it's one-to-many associated objects in a single transaction. It's important because the object should not exist without the associated objects, so if something goes wrong the whole transaction should be rolled back.

Hibernate version: 3.1

Mapping documents:
Procedure:

Code:

<hibernate-mapping package="com.package">
    <class name="Procedure" table="procedures" schema="public">
        <id name="id" type="int">
            <column name="procedure_id" />
            <generator class="sequence">
                <param name="sequence">
                    procedure_id_seq
                </param>
            </generator>
        </id>
        <set name="procedureParameters" inverse="true" cascade="persist,merge,save-update">
            <key>
                <column name="procedure_id" not-null="true" />
            </key>
            <one-to-many class="ProcedureParameter" />
        </set>
    </class>
</hibernate-mapping>

ProcedureParameter:

Code:

<hibernate-mapping package="com.package">
    <class name="ProcedureParameter" table="procedure_parameters" schema="public">
        <composite-id name="id" class="ProcedureParameterId">
            <key-property name="parameterCode" type="string">
                <column name="parameter_code" length="12" />
            </key-property>
            <key-property name="procedureId" type="int">
                <column name="procedure_id"/>
            </key-property>
        </composite-id>
        <many-to-one name="procedure" class="Procedure" update="false" insert="false" fetch="select">
            <column name="procedure_id" not-null="true" />
        </many-to-one>
        <property name="value" type="string">
            <column name="value" length="250" />
        </property>
        <property name="remarks" type="string">
            <column name="remarks" length="100" />
        </property>
    </class>
</hibernate-mapping>

Objects in question (stubs only):
Procedure:

Code:

public class Procedure {
   private Integer id;
   private Set<ProcedureParameter> procedureParameters = new HashSet<ProcedureParameter>(0);
}

ProcedureParameter:

Code:

public class ProcedureParameter {
   private ProcedureParameterId id;
   private String value;
   private String remarks;

   private Procedure procedure;
}

ProcedureParameterId:

Code:

public class ProcedureParameterId {
   private String parameterCode;
   private Integer procedureId;
}

Normally I would do something like this (everything within one hibernate session):

Code:

BEGIN TRANSACTION 1

Procedure procedure = new Procedure();
HibernateSession.save(procedure);

COMMIT TRANSACTION 1

BEGIN TRANSACTION 2

ProcedureParameter procParam1 = new ProcedureParameter(new ProcedureParameterId("PARAM1", procedure.getId()), "value1", "remark1");
ProcedureParameter procParam2 = new ProcedureParameter(new ProcedureParameterId("PARAM2", procedure.getId()), "value2", "remark2");
procedure.getProcedureParameters().add(procParam1);
procedure.getProcedureParameters().add(procParam2);
// save not needed - cascade will take care of inserting procedure parameters

COMMIT TRANSACTION 2

But as I mentioned before this has to be done in a single transaction. Is there any way to bind ProcedureParameterId.procedureId to Procedure.id so that once created Procedure.id taken from procedure_id_seq would be known "behind the scenes" to ProcedureParameterId.procedureId?
What I would like is something like this:

Code:

BEGIN TRANSACTION
Procedure procedure = new Procedure();   // gets id only at the commit

ProcedureParameter procParam1 = new ProcedureParameter(new ProcedureParameterId("PARAM1", ???), "value1", "remark1");
ProcedureParameter procParam2 = new ProcedureParameter(new ProcedureParameterId("PARAM2", ???), "value2", "remark2");
procedure.getProcedureParameters().add(procParam1);
procedure.getProcedureParameters().add(procParam2);

HibernateSession.save(procedure);

COMMIT TRANSACTION

Any ideas?

evdelst · **Joined:** Wed Aug 24, 2005 11:49 am **Posts:** 63

Don't map the foreign-key from procedureparameter to procedure as an int, but map it as a key-many-to-one.
Then, you can put the 'unsaved' Procedure object in it, and during the commit, Hibernate will take care of the rest.

cbourque · **Joined:** Mon Oct 22, 2007 8:27 pm **Posts:** 7

evdelst wrote:

Don't map the foreign-key from procedureparameter to procedure as an int, but map it as a key-many-to-one.
Then, you can put the 'unsaved' Procedure object in it, and during the commit, Hibernate will take care of the rest.

Hi,

When I do that I get: "ids for this class must be manually assigned before calling save():..."!

Is it really possible to do that without first saving the parent object?

Thanks

Christian

evdelst · **Joined:** Wed Aug 24, 2005 11:49 am **Posts:** 63

Shouldn't the key-property be a key-many-to-one ?
(From parameter to procedure)

Edwin