I'm sorry to bump my own thread, but I am quite stuck. Just to make sure: using OData / DataService to generate the queries, NHibernate does handle an $expand query for objects with a one-to- many / many-to-one relationship? Or is there a known bug in NHibernate? I am returning a NhQueryable<DesignerEntity> for the basic query in my data context.
This is my $metadata, if that helps: <edmx:Edmx xmlns:edmx="http://schemas.microsoft.com/ado/2007/06/edmx"; Version="1.0"> <script/> <edmx:DataServices xmlns:m="http://schemas.microsoft.com/ado/2007/08/ dataservices/metadata" m:DataServiceVersion="1.0"> <Schema xmlns:d="http://schemas.microsoft.com/ado/2007/08/ dataservices" xmlns:m="http://schemas.microsoft.com/ado/2007/08/ dataservices/metadata" xmlns="http://schemas.microsoft.com/ado/2007/05/ edm" Namespace="ODataTest"> <EntityType Name="Widget"> <Key> <PropertyRef Name="Id"/> </Key> <Property Name="Id" Type="Edm.Guid" Nullable="false"/> <NavigationProperty Name="Designer" Relationship="ODataTest.Designer_Widgets_Widget_Designer" FromRole="Widget_Designer" ToRole="Designer_Widgets"/> </EntityType> <EntityType Name="Designer"> <Key> <PropertyRef Name="Id"/> </Key> <Property Name="Id" Type="Edm.Guid" Nullable="false"/> <NavigationProperty Name="Widgets" Relationship="ODataTest.Designer_Widgets_Widget_Designer" FromRole="Designer_Widgets" ToRole="Widget_Designer"/> </EntityType> <Association Name="Designer_Widgets_Widget_Designer"> <End Role="Designer_Widgets" Type="ODataTest.Designer" Multiplicity="0..1"/> <End Role="Widget_Designer" Type="ODataTest.Widget" Multiplicity="*"/> </Association> <EntityContainer Name="Container" m:IsDefaultEntityContainer="true"> <EntitySet Name="Widgets" EntityType="ODataTest.Widget"/> <EntitySet Name="Designers" EntityType="ODataTest.Designer"/> <AssociationSet Name="WidgetDesignerAssociationSet" Association="ODataTest.Designer_Widgets_Widget_Designer"> <End Role="Designer_Widgets" EntitySet="Designers"/> <End Role="Widget_Designer" EntitySet="Widgets"/> </AssociationSet> </EntityContainer> </Schema> </edmx:DataServices> </edmx:Edmx> Thanks for any advice!! On Dec 16, 12:12 pm, Paul <[email protected]> wrote: > I'm pretty new to nHibernate, so I'm most likely doing something very > dumb. I am using nHibernate 3.2 GA. I have two objects, "Widget" and > "Designers". A widget knows its designer, and it has only one > designer. A designer has many widgets, and it know of all of them. > Thus, these entities: > > public class WidgetEntity > { > public virtual Guid Id { get; set; } > public virtual DesignerEntity Designer { get; set; } > > } > > public class DesignerEntity > { > public virtual Guid Id { get; set; } > public virtual string Name { get; set; } > public virtual string Address { get; set; } > > public virtual ICollection<WidgetEntity> Widgets { get; set; } > > } > > I've created the following two mappings: > > <hibernate-mapping xmlns='urn:nhibernate-mapping-2.2' > assembly='ODataTest' namespace='ODataTest' > > <class name='WidgetEntity' table='WidgetEntity' > > <id name='Id' column='Id' > > <generator class='guid.comb' /> > </id> > <many-to-one name='Designer' class='DesignerEntity' > column='DesignerId' foreign-key='FK_DESIGNER_WIDGETS' cascade='save- > update' /> > </class> > </hibernate-mapping> > > <hibernate-mapping xmlns='urn:nhibernate-mapping-2.2' > assembly='ODataTest' namespace='ODataTest'> > <class name='DesignerEntity' table='DesignerEntity'> > <id name='Id' column='Id'> > <generator class='guid.comb' /> > </id> > <set lazy='true' name='Widgets' inverse='true'> > <key column='DesignerId' /> > <one-to-many class='WidgetEntity' /> > </set> > </class> > </hibernate-mapping> > > Basic queries for either widgets or designers work great; no > problems. But I am using this in context of an OData server, and so > when I am issue a command > likehttp://[SERVER]/WidgetService/Designers(guid'[ID]')/?$expand=Widgets, > I get an exception back. OData is by-and-large hiding the nHibernate > LINQ command, but inferring from stepping through the code, I think > this is the exact command / expression being passed to > DefaultQueryProvider.Execute: > > value(NHibernate.Linq.NhQueryable`1[ODataTest.DesignerEntity]).Where(elemen t > => (element.Id == d5e3ce36-b0d0-49e7-b104-28029ff59414)).Select(p => > new ExpandedWrapper`2() {ExpandedElement = p, Description = "Widgets", > ProjectedProperty0 = p.Widgets}) > > The resulting SQL query is this: > > exec sp_executesql N'select designeren0_.Id as Id1_0_, widgets1_.Id as > Id0_1_, widgets1_.DesignerId as DesignerId0_1_ from DesignerEntity > designeren0_ inner join WidgetEntity widgets1_ on > designeren0_.Id=widgets1_.DesignerId where designeren0_.Id=@p0',N'@p0 > uniqueidentifier',@p0='D5E3CE36-B0D0-49E7-B104-28029FF59414' > > I hacked out some columns for brevity sake. My SQL server likes this > just fine, and returns two rows. However, when attempting to > transform the SQL result into my returned data, I get an exception. > What it comes down to is an InvalidCastException: "Unable to cast > object of type 'ODataTest.WidgetEntity' to type > 'System.Collections.Generic.ICollection`1[ODataTest.WidgetEntity]'." > The exact location is in ResultTransformer.cs, line 25: > > return _itemTransformation == null ? tuple : > _itemTransformation.DynamicInvoke(new object[] {tuple}); > > _itemTransformation is "{Method = > {System.Data.Services.Internal.ExpandedWrapper`2[ODataTest.DesignerEntity,S > ystem.Collections.Generic.IEnumerable`1[ODataTest.WidgetEntity]] > lambda_method(System.Runtime.CompilerServices.Closure, > System.Object[])}}". tuple is an array of two objects. The first is > my DesignerEntity, complete with Widgets ICollection filled in. The > second is a single WidgetEntity, the values of which correlate to the > first SQL result row. > > At this point, I have no idea what's going on. :) I am supposing > that the problem is in my hbm files. I have tried setting up many-to- > one without cascade (which, I would think, doesn't matter here since > I'm only doing a select). I have tried setting up the one-to-many as > a bag, and both with and without the inverse. > > Apologies if I'm missing some information, or this is too much > information. Any help would be appreciated... I've been pulling my > hair for a couple of days on this. :) Thanks!! -- You received this message because you are subscribed to the Google Groups "nhusers" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/nhusers?hl=en.
