Hello, I am new at Hibernate and I need help with this problem:
I have the 
Service entity, which contains a 
Set<ServicePeriod>. Both entities are mapped to corresponding tables.
I do the following:
1) Retrieve 
Service by id
2) Add a new 
ServicePeriod to it (bidirectional association)
3) Perform an update on the 
Service object retrieved in (1)
After these operations, I can see the new 
ServicePeriod has been written correctly to database, but the field 
servicePeriodId (in Java object) is still null. I need this field not to be null, so I can perform other tasks using that value.
I am using SQL Server 2005.
These are the classes
Code:
public class Service {
   private String serviceCode;
   private Set<ServicePeriod> servicePeriods;
   // other fields, constructors, getters and setters...
   
   public void addServicePeriod(ServicePeriod servicePeriod){
      if (this.servicePeriods == null){
         this.servicePeriods = new HashSet<ServicePeriod>();
      }
      this.servicePeriods.add(servicePeriod);
      servicePeriod.setServiceCode(this);
   }
}
public class ServicePeriod {
   private Integer servicePeriodId;
   private Service serviceCode;
   
   // other fields, constructors, getters and setters
}
And these are the HBM mappings:
Code:
<class name="mypackage.Service" table="service">
   <id name="serviceCode" type="string">
      <column name="service_code" length="5" />
      <generator class="assigned" />
   </id>
   <!-- other properties... -->       
   <set name="servicePeriods" inverse="true" cascade="all-delete-orphan">
      <key><column name="service_code" /></key>
      <one-to-many class="mypackage.ServicePeriod" />
   </set>
</class>
<class name="mypackage.ServicePeriod" table="service_period">
   <id name="servicePeriodId" type="int">
      <column name="service_period_id" />
      <generator class="native" />
   </id>
   <many-to-one name="serviceCode" class="mypackage.Service">
      <column name="service_code" length="5" not-null="true" />
   </many-to-one>
   <!-- other properties... -->
</class>
I will appreciate your help. Thanks in advance.