Question

I’m using Hibernate with Spring and Hibernate return this error:

Caused by: java.sql.BatchUpdateException: Column 'ID_TAREA_FK' cannot be null

I have two classes

public class Tarea {
 private List<Sesion> sesiones;
}

public class Sesion {
 private Tarea tarea;
}

With their getters and setters. In my code, I don’t forget

t.getSesiones().add(s);
s.setTarea(t);

The database tables are:
TAREAS { ID_TAREA, … }, SESIONES { ID_SESION, ID_TAREA_FK, … }

The pieco of code in Tarea.hbm.xml for the list sesiones is:

<bag name="sesiones" table="SESIONES" inverse="true" cascade="all">
 <key column="ID_TAREA" not-null="true" />
 <one-to-many class="com.jonasurbano.tareas.domain.sesiones.Sesion" />
</bag>

In Sesion.hbm.xml:

<many-to-one name="tarea" class="com.jonasurbano.tareas.domain.tareas.Tarea" not-null="true">
 <column name="ID_TAREA_FK" />
</many-to-one>

What am I doing wrongly? I’ve read Hibernate documentation and this post Hibernate One To Many Problem but it doesn’t work for me.

After working out this problem, I would like to know if there is some way to avoid the reference Tarea in class Sesion because I think this property is redundant.

Thanks a lot!

Answer 1

• Check your database constraints. Probably ID_TAREA_FK has not null constraint, try to remove this constraint, because Hibernate saves the identity column first with null values at all other columns.

• Delete not-null=”true”.

  <key column="ID_TAREA" />
  

• Rewrite mapping in one string:

  <many-to-one name="tarea" class="com.jonasurbano.tareas.domain.tareas.Tarea" not-null="true"  column="ID_TAREA_FK"/>
  

Read this if something wrong with mapping and nothing helps you http://docs.jboss.org/hibernate/core/3.3/reference/en/html/collections.html#collections-bidirectional