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 Post subject: Duplicated Objects
PostPosted: Fri Sep 17, 2010 4:55 am 
Newbie

Joined: Mon Jul 26, 2010 2:25 am
Posts: 6
I was playing around with NHibernate 3 Alpha 2 and created a simple Model.
I've a Customer, with a List of Orders, which are Mapped to Products by OrderLine.

Now when I'm loading a Customer, I get duplicate Orders (one for every OrderLine it has).

The Mapping (simplified):
Code:
  <class name="Customer" table="Customer" >
    <id name="Id" type="long" unsaved-value="0">
      <generator class="native" />
    </id>

    {Properties omitted}

    <bag name="Orders" cascade="all-delete-orphan" inverse="true" lazy="true">
      <key column="CustomerId" not-null="true" on-delete="cascade"/>
      <one-to-many class="Order"/>
    </bag>
  </class>

  <class name="Order" table="[Order]" lazy="false">
    <id name="Id" type="long" unsaved-value="0">
      <generator class="native" />
    </id>

    {Properties omitted}

    <many-to-one name="OrderedBy" class="Customer" column="CustomerId" />

    <bag name="OrderLines" cascade="all-delete-orphan" inverse="true" lazy="true">
      <key column="OrderId" not-null="true" on-delete="cascade"/>
      <one-to-many class="OrderLine"/>
    </bag>
  </class>

  <class name="OrderLine" table="OrderLine" >
    <composite-id name="Id" class="OrderLineKey">
      <key-many-to-one name="Order" column="OrderId" lazy="proxy" class="Order"/>
      <key-many-to-one name="Product" column="ProductId" lazy="proxy" class="Product"/>
    </composite-id>

    {Properties omitted}
  </class>

  <class name="Product" table="Product" lazy="false">
    <id name="Id" type="long" unsaved-value="0">
      <generator class="native" />
    </id>

    {Properties omitted}
  </class>


OrderLineKey Class:
Code:
    public class OrderLineKey {
        public virtual Order Order { get; set; }
        public virtual Product Product { get; set; }

        {GetHashCode/Equals Omitted}
    }


This is the loading:
Code:
this.Session.QueryOver<Customer>()
                .Where(e => e.Id == customerId)
                .Fetch(f => f.Orders).Eager
                .Fetch(f => f.Orders.First().OrderLines).Eager
                .SingleOrDefault()


I don't know if there is a conceptual error in my model or mapping, any advice would be appreciated.


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 Post subject: Re: Duplicated Objects
PostPosted: Fri Sep 17, 2010 6:05 am 
Expert
Expert

Joined: Thu Dec 14, 2006 5:57 am
Posts: 1185
Location: Zurich, Switzerland
http://nhforge.org/wikis/howtonh/get-unique-results-from-joined-queries.aspx

_________________
--Wolfgang


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 Post subject: Re: Duplicated Objects
PostPosted: Fri Sep 17, 2010 6:14 am 
Newbie

Joined: Mon Jul 26, 2010 2:25 am
Posts: 6
Tried the DistinctRootEntityResultTransformer, but this does not work on the nested objects.


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 Post subject: Re: Duplicated Objects
PostPosted: Fri Sep 17, 2010 7:32 am 
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Expert

Joined: Thu Dec 14, 2006 5:57 am
Posts: 1185
Location: Zurich, Switzerland
Hmm, you can try and map the orders as <set> or <list> which both do not allow duplicate entries. Then only one of each item will be added

_________________
--Wolfgang


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