Issue with join configuration

ascalonx · **Joined:** Mon Dec 03, 2007 3:53 pm **Posts:** 1

Need help with Hibernate? Read this first:
http://www.hibernate.org/ForumMailingli ... AskForHelp

Hibernate version: 2.0.0.1001

Mapping documents:

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
namespace="Panther.Schedule"
assembly="panther.sched.nhibernate">

<class name="Panther.Scheduling.ScheduledQuery, panther.sched.nhibernate"
table="MessageScheduleRecurrenceQuery" >

<id name="ScheduleRecurrenceId" access="Panther.Scheduling.NHibernate.MUnderBarPropertyAccessor, panther.sched.nhibernate"
column="ScheduleRecurrenceID"
type="Int32">
<generator class="assigned"/>
</id>

<property name="ScheduleRecurrenceId" access="Panther.Scheduling.NHibernate.MUnderBarPropertyAccessor, panther.sched.nhibernate"/>

<property name="SendOnEmpty" access="Panther.Scheduling.NHibernate.MUnderBarPropertyAccessor, panther.sched.nhibernate"/>
<property name="SendOnError" access="Panther.Scheduling.NHibernate.MUnderBarPropertyAccessor, panther.sched.nhibernate"/>

<set name="Parameters" access="Panther.Scheduling.NHibernate.MUnderBarPropertyAccessor, panther.sched.nhibernate">
<key property-ref="ScheduleRecurrenceId"/>
<one-to-many class="Panther.Scheduling.ScheduledQuery+Parameter, panther.sched.nhibernate" />
</set>

<join table="ScheduledQueryLib">
<key column="ScheduledQueryID" foreign-key="ScheduledQueryID" property-ref="ScheduledQueryId"/>
<property name="Name" access="Panther.Scheduling.NHibernate.MUnderBarPropertyAccessor, panther.sched.nhibernate"/>
<property name="ProcedureName" access="Panther.Scheduling.NHibernate.MUnderBarPropertyAccessor, panther.sched.nhibernate"/>
</join>

</class>
</hibernate-mapping>

Code between sessionFactory.openSession() and session.close():

using (tx = session.BeginTransaction ())
{
return session.Get <ScheduledQuery> (pk);
}

Name and version of the database you are using: MsSql2005

The generated SQL (show_sql=true):

SELECT scheduledq0_.ScheduleRecurrenceID as Schedule1_4_0_, scheduledq0_.SendOnEmpty as SendOnEm2_4_0_, scheduledq0_.SendOnError as SendOnEr3_4_0_, scheduledq0_1_.Name as Name5_0_, scheduledq0_1_.ProcedureName as Procedur3_5_0_ FROM MessageScheduleRecurrenceQuery scheduledq0_ inner join ScheduledQueryLib scheduledq0_1_ on scheduledq0_.ScheduleRecurrenceID = scheduledq0_1_.ScheduledQueryID WHERE scheduledq0_.ScheduleRecurrenceID=?

I was hoping for this to actually generate:

SELECT scheduledq0_.ScheduleRecurrenceID as Schedule1_4_0_, scheduledq0_.SendOnEmpty as SendOnEm2_4_0_, scheduledq0_.SendOnError as SendOnEr3_4_0_, scheduledq0_1_.Name as Name5_0_, scheduledq0_1_.ProcedureName as Procedur3_5_0_ FROM MessageScheduleRecurrenceQuery scheduledq0_ inner join ScheduledQueryLib scheduledq0_1_ on scheduledq0_.[b]ScheduledQueryID[\b]=scheduledq0_1_.ScheduledQueryID WHERE scheduledq0_.ScheduleRecurrenceID=?

If I change it to that and run it in Server Management Studio, it comes back with a result, but without the change I get nothing. This is because ScheduledQueryID on the MessageScheduleRecurrenceQuery table is a foreign key into the ScheduledQueryLib table but the <join> tag seems to be assuming that it goes the other way.

Does anyone have any ideas on how to achieve the desired behavior?

karlchu · **Posted:** Mon Dec 03, 2007 8:24 pm

Please create a JIRA issue referencing this thread. Thanks.

Karl

PS: The <join> feature is still under development and shall be considered experimental at this time.

benjamin.arroyo · **Joined:** Thu Jul 09, 2009 12:33 pm **Posts:** 1

Just set IsInverse property of the Join to True:

Code:

<join table="ScheduledQueryLib" IsInverse="True">
...
</join> 

For more information, have a look to the source code: https://nhibernate.svn.sourceforge.net/ ... ng/Join.cs

Code:

public void CreateForeignKey()
      {
         // TODO: The "if (!IsInverse)" condition is not in H3.2.
         // Not sure if this H3.2 does it in a different way.  The reason
         // this condition is put in is because when a <join> is mapped with
         // inverse="true", the joined rows should not be deleted (see 
         // comments in NH-466).  In other words, the joined row is
         // outside of the parent row's life cycle.  If this foreign
         // key is added, the parent row cannot be deleted independent
         // of the joined row.  Perhaps we need more clarification
         // on how this should behave.
         if (!IsInverse)
         {
            Key.CreateForeignKeyOfEntity(persistentClass.EntityName);
         }
      }

Regards.
Ben.