FluentNhibernate Mapping Using References Index Out of Range When Adding new Object

Question

I am trying to map a parent child relationship between a Person object and a Organization object in FluentNHibernate using References in the mapping file like this:

References(x => x.Organization);

The relationship is a Person object contains a OrganizationId column that corresponds to a record in the Organization table with the corresponding OrganizationId. Different Person records can belong to the same Organization.

When I retrieve a Person object it works properly. Person.Organization is populated. I can save a Person object and it works properly. However, when I attempt to add a new Person object I get a Index Out of Range exception from NHibernate. The exception occurs when calling session.SaveOrUpdate(person). I've tried changing the mapping to:

References(x => x.Organization).Cascade.None()

Still get the same error. I can't figure out what is causing the exception. The full exception is this:

System.IndexOutOfRangeException : Invalid index 22 for this SqlParameterCollection with Count=22. at System.Data.SqlClient.SqlParameterCollection.RangeCheck(Int32 index) at System.Data.SqlClient.SqlParameterCollection.GetParameter(Int32 index) at System.Data.Common.DbParameterCollection.System.Collections.IList.get_Item(Int32 index) at NHibernate.Type.NullableType.NullSafeSet(IDbCommand cmd, Object value, Int32 index) at NHibernate.Type.ManyToOneType.NullSafeSet(IDbCommand st, Object value, Int32 index, Boolean[] settable, ISessionImplementor session) at NHibernate.Persister.Entity.AbstractEntityPersister.Dehydrate(Object id, Object[] fields, Object rowId, Boolean[] includeProperty, Boolean[][] includeColumns, Int32 table, IDbCommand statement, ISessionImplementor session, Int32 index) at NHibernate.Persister.Entity.AbstractEntityPersister.GeneratedIdentifierBinder.BindValues(IDbCommand ps) at NHibernate.Id.Insert.AbstractReturningDelegate.PerformInsert(SqlCommandInfo insertSQL, ISessionImplementor session, IBinder binder) at NHibernate.Persister.Entity.AbstractEntityPersister.Insert(Object[] fields, Boolean[] notNull, SqlCommandInfo sql, Object obj, ISessionImplementor session) at NHibernate.Persister.Entity.AbstractEntityPersister.Insert(Object[] fields, Object obj, ISessionImplementor session) at NHibernate.Action.EntityIdentityInsertAction.Execute() at NHibernate.Engine.ActionQueue.Execute(IExecutable executable) at NHibernate.Event.Default.AbstractSaveEventListener.PerformSaveOrReplicate(Object entity, EntityKey key, IEntityPersister persister, Boolean useIdentityColumn, Object anything, IEventSource source, Boolean requiresImmediateIdAccess) at NHibernate.Event.Default.AbstractSaveEventListener.SaveWithGeneratedId(Object entity, String entityName, Object anything, IEventSource source, Boolean requiresImmediateIdAccess) at NHibernate.Event.Default.DefaultSaveOrUpdateEventListener.SaveWithGeneratedOrRequestedId(SaveOrUpdateEvent event) at NHibernate.Event.Default.DefaultSaveOrUpdateEventListener.EntityIsTransient(SaveOrUpdateEvent event) at NHibernate.Event.Default.DefaultSaveOrUpdateEventListener.OnSaveOrUpdate(SaveOrUpdateEvent event) at NHibernate.Impl.SessionImpl.FireSaveOrUpdate(SaveOrUpdateEvent event) at NHibernate.Impl.SessionImpl.SaveOrUpdate(Object obj)

Answer 1

First of all the exception occurs because you map the same column twice in your class and that is not allowed. check this http://stackoverflow.com/questions/2298026/indexoutofrangeexception-deep-in-the-bowels-of-nhibernate/2311256#2311256

Secondly (and according to your latest comment) having an OrganizationId and an Organization property in your Person class is sort-of going against the grain. You don't need it. You can access it via per1.Organization.Id

If you already have an Organization in your db (say Id=5) and you map the Organization class to the Person class using the OrganizationId foreign key, then when you code

Organization theOrganizationWithId5 = nhSession.Get<Organization>(5);
per1.Organization = theOrganizationWithId5;
nhSession.Save(per1);

NHibernate will just set the value 5 on the OrganizationId column in your Person table. You will not be populating Organization.