Update to child of many-to-one updates the parent

gcook1@shaw.ca · **Joined:** Tue Feb 07, 2006 4:27 pm **Posts:** 69

I have 2 classes related to each other through a
uni-directional many-to-one relationship.

Parent Child
-------------------- -----------------

TradeInformation <-- TradeSchedule

When we update the TradeSchedule (child) object, it also updates the parent even though the TradeInformation (parent) hasn't been changed within the session.

We have other many-to-one mappings in our system and they do not exhibit the same behavior so I'm wondering this has something to do with the Schedule hierarchy or if we have missed something obvious...

Also from one session to the next, it would be great if you could mark
which classes are NONMUTABLE. This could really speed up performance because NHibernate could ignore the objects marked as such on a session-by-session basis.

Here are our mappings...

TradeInformation.hbm.xml

Code:

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
                   assembly="MyDomain" namespace="MyDomain.Trade" auto-import="true" >
  <class name="TradeInformation" table="trade" lazy="false" dynamic-insert="true" dynamic-update="true"> 
    <id name="Id" column="trade_id" type="Int32">
      <generator class="native" />
    </id>

    <properties.../>
   
   <many-to-one name="CurrentShape" class="MyDomain.Shapes.Shape" column="Shape_Id" access="field.camelcase"/>     
    <bag name="Details" table="trade_detail" inverse="true" cascade="all"  fetch="select" lazy="false">
      <key column="trade_id" />
      <one-to-many class="TradeDetail" />
    </bag>
    
  </class>  
</hibernate-mapping>

TradeSchedule

Code:

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
                   assemblyMyDomain" namespaceMyDomain.Scheduling" auto-import="true" >
  
  <subclass name="TradeSchedule" extends="Schedule" lazy="false" discriminator-value="T">
  <many-to-one name="Trade" class="MyDomain.Trade.TradeInformation" column="trade_Id" access="field.camelcase"/>
  </subclass>  

</hibernate-mapping>

Schedule

Code:

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
                   assembly="MyDomain" namespace="MyDomain.Scheduling" auto-import="true" >
  <class name="Schedule" table="Schedule" lazy="false" dynamic-insert="true" dynamic-update="true">
    <cache usage="read-write"/>

    <id name="Id" column="schedule_id" type="Int32">
      <generator class="native" />
    </id>

    <discriminator column="Schedule_Indicator" type="String" length="1"/>
     
    <properties/>   

    <many-to-one name="Parent" class="Schedule" column="Parent_Id" access="field.camelcase"/>
   <many-to-one name="CurrentShape" class="MyDomain.Shapes.Shape" column="shape_id" access="field.camelcase" not-null="false"/>
     
   <bag name="Children" inverse="true" lazy="false" cascade="all">
     <key column="Parent_Id"/>
     <one-to-many class="Schedule"/>
   </bag>  

   <bag name="Transactions" inverse="true" lazy="false" >
     <key column="schedule_id"/>
     <one-to-many class="ScheduleTransaction"/>
   </bag>

   <bag name="Internal_Details" inverse="true" lazy="false" cascade="all">
     <key column="schedule_id"/>
     <one-to-many class="ScheduleDetail"/>
   </bag>

  </class>
  
</hibernate-mapping>

tjtannahill · **Joined:** Mon Jul 07, 2008 2:29 pm **Posts:** 1

I'm having this problem too. Does anyone out there have any ideas?

- Thomas

wolli · **Posted:** Tue Jul 08, 2008 2:15 am

Where did you see that an update happened ? Just in hibernate's log or really in the database ? Maybe it's just a misleading log info ?

Dou you have version or timestamp columns in these classes ? Can you post the debug log ?

gcook1@shaw.ca · **Joined:** Tue Feb 07, 2006 4:27 pm **Posts:** 69

wolli wrote:

Where did you see that an update happened ? Just in hibernate's log or really in the database ? Maybe it's just a misleading log info ?

Dou you have version or timestamp columns in these classes ? Can you post the debug log ?

Thanks for the reply. I didn't notice this in the logs at all.
We are using a custom Audit Interceptor to update the LastModifiedBy and LastModifiedByDate fields of the Trade when it is updated.

I will tho turn on the NHibernate logs and run our test and capture the log information for you.

wolli · **Posted:** Tue Jul 08, 2008 1:23 pm

Does this also happen when you disable the audit interceptor ?

wolli · **Posted:** Tue Jul 08, 2008 1:23 pm

Double posting, sorry.

gcook1@shaw.ca · **Joined:** Tue Feb 07, 2006 4:27 pm **Posts:** 69

wolli wrote:

Where did you see that an update happened ? Just in hibernate's log or really in the database ? Maybe it's just a misleading log info ?

Dou you have version or timestamp columns in these classes ? Can you post the debug log ?

Hey! What a novel idea. Turning on the log!

I discovered what the issue was. One of the fields of the TradeInformation object is an enumerated type which I had mapped as Int32 instead of letting NHibernate reflect on the type for this field.

When NHibernate checked if this object was dirty it also checked the type and thought it dirty. I removed the type definition for this field and it is now working as expected.

Thanks for the tips and in the future I'll be turning on the logs a bit more!

Cheers

-Greg