Josh: I've tried reproducing your problem, but I haven't been able to. I
created a Product class, a ProductMap, and then wrote a little unit test to
see if it worked, and it did.
<TestFixture()> _
Public Class VbLinqTests
Private _source As ISessionSource
<SetUp()> _
Public Sub CreateDatabase()
Dim properties As IDictionary(Of String, String) = New
SQLiteConfiguration() _
.UseOuterJoin() _
.InMemory() _
.ToProperties()
_source = New
SingleConnectionSessionSourceForSQLiteInMemoryTesting(properties, New
TestModel())
_source.BuildSchema()
End Sub
<Test()> _
Public Sub TestLinq()
Dim flRepos As New Repository(_source)
flRepos.Save(New Product())
flRepos.Save(New Product())
flRepos.Save(New Product())
flRepos.Save(New Product())
Dim product As Product = flRepos.Query(Of Product)(Function(p As
Product) p.Id > 1).ToList().FirstOrDefault
Assert.NotNull(product)
End Sub
End Class
Can you try running that yourself to see what happens?
On Tue, Jan 6, 2009 at 11:00 PM, Josh Pollard <j...@glmotorsports.net>wrote:
>
> I did some more investigating and it looks like Linq2NHib only pukes
> when using lambda expressions in VB. The following works:
>
> Dim product = (From p In session.Linq(Of Product)() _
> Where p.Id = testId _
> Select p).FirstOrDefault()
>
> Obviously that isn't using Fluent NHib at all. So the question is, how
> do I use Fluent NHib without using lambdas? I think the problem is
> that I don't know what us as my "in"
>
> Any ideas on how to cram a full linq query into the Fluent NHib Query
> method?
>
> On Jan 5, 3:31 pm, "Jeremy Skinner" <jer...@jeremyskinner.co.uk>
> wrote:
> > I can't be certain as I haven't got VB installed to test this, but it
> > certainly appears to be the case. Linq to NHibernate's unit tests are all
> in
> > C# so it doesn't surprise me that the differences in VB's expression
> trees
> > have been missed.
> >
> > 2009/1/5 RalyDSM <j...@glmotorsports.net>
> >
> >
> >
> > > so I guess i need to take this problem to the linq-to-nhibernate
> > > guys...
> >
> > > On Jan 5, 3:19 pm, "Jeremy Skinner" <jer...@jeremyskinner.co.uk>
> > > wrote:
> > > > Yep, you'll notice there's no where clause on the query. Its loading
> the
> > > > entire table then performing an in-memory linq query.
> >
> > > > 2009/1/5 RalyDSM <j...@glmotorsports.net>
> >
> > > > > are you SURE about the compile thing? When I turn on the show_sql
> > > > > property in NHibernate this is the query that is written:
> > > > > SELECT this_.Id as Id2_0_, this_.Title as Title2_0_ FROM [Product]
> > > > > this_
> >
> > > > > On Jan 5, 3:04 pm, "Jeremy Skinner" <jer...@jeremyskinner.co.uk>
> > > > > wrote:
> > > > > > I don't think this is an issue with the Repository, rather an
> issue
> > > with
> > > > > > Linq to NHibernate. The VB and C# compilers (unhelpfully) create
> > > > > expression
> > > > > > trees differently. My guess is the Linq to NHibernate code does
> not
> > > parse
> > > > > VB
> > > > > > expression trees correctly (I can't verify this as I don't have
> VB
> > > > > installed
> > > > > > on this machine).
> >
> > > > > > You don't want to be calling where.Compile() - this causes the
> > > expression
> > > > > > tree to be compiled into a delegate and can no longer be
> translated
> > > into
> > > > > SQL
> > > > > > - instead this ends up loading the entire table into your
> application
> > > and
> > > > > > then doing an *in-memory* filter (bypassing Linq to NHibernate's
> > > > > expression
> > > > > > tree parsing).
> > > > > > Jeremy
> > > > > > 2009/1/5 James Gregory <jagregory....@gmail.com>
> >
> > > > > > > That's very interesting. Unfortunately, the bits in the
> Framework
> > > > > > > project are rather neglected, so there may very-well be a bug
> in
> > > > > > > there. I need to investigate this before I can pass judgement
> > > though.
> >
> > > > > > > On 1/5/09, RalyDSM <j...@glmotorsports.net> wrote:
> >
> > > > > > > > I think I might have found a bug, but I'm not really sure. It
> > > could
> > > > > be
> > > > > > > > a syntax error on my part, but the compiler isn't catching.
> > > Anyway,
> > > > > > > > here is what I'm trying to do. Basically I've written my own
> > > > > > > > repository class that essentially just wraps the Fluent
> > > Repository
> > > > > > > > class. So here is the relevant code:
> >
> > > > > > > > Public Class GenericRepository(Of T As IHasIntId)
> >
> > > > > > > > Private _fluentRepos As
> > > FluentNHibernate.Framework.IRepository
> >
> > > > > > > > Public Sub New(ByVal FluentRepository As
> > > > > > > > FluentNHibernate.Framework.IRepository)
> > > > > > > > _fluentRepos = FluentRepository
> > > > > > > > End Sub
> >
> > > > > > > > Private Sub New()
> >
> > > > > > > > End Sub
> >
> > > > > > > > Public Function GetById(ByVal Id As Integer) As T
> >
> > > > > > > > Return Query(Function(x As T) (x.Id =
> Id)).FirstOrDefault
> >
> > > > > > > > End Function
> >
> > > > > > > > Public Function Query(ByVal w As Expression(Of
> System.Func(Of
> > > T,
> > > > > > > > Boolean))) As IList(Of T)
> >
> > > > > > > > Return _fluentRepos.Query(Of T)(w).ToList()
> >
> > > > > > > > End Function
> >
> > > > > > > > End Class
> >
> > > > > > > > Then I wrote two unit tests, one that would pass in an
> > > > > > > > InMemoryRepository and one that would use an actual
> NHibernate
> > > > > session
> > > > > > > > to hit the real database.
> >
> > > > > > > > here they are:
> >
> > > > > > > > <TestMethod()> Public Sub InMemoryTest()
> >
> > > > > > > > Dim inmemRepos As New InMemoryRepository()
> >
> > > > > > > > Dim p As New Product()
> > > > > > > > Dim id As Integer = 5
> > > > > > > > p.Id = id
> > > > > > > > p.Title = "my product"
> >
> > > > > > > > inmemRepos.Save(p)
> >
> > > > > > > > Dim genRepos As New GenericRepository(Of
> > > Product)(inmemRepos)
> >
> > > > > > > > Dim foundP = genRepos.GetById(id)
> >
> > > > > > > > Assert.AreEqual(p.Title, foundP.Title)
> >
> > > > > > > > End Sub
> >
> > > > > > > > <TestMethod()> Public Sub DatabaseTest()
> >
> > > > > > > > Dim session =
> > > NHibernateSessionManager.Instance.GetSession()
> >
> > > > > > > > Dim flRepos As New Repository(session)
> > > > > > > > Dim genRepos As New GenericRepository(Of
> > > Product)(flRepos)
> >
> > > > > > > > Dim id As Integer = 1
> >
> > > > > > > > Dim p = genRepos.GetById(id)
> >
> > > > > > > > Assert.IsNotNull(p)
> > > > > > > > Assert.AreEqual(id, p.Id)
> >
> > > > > > > > End Sub
> >
> > > > > > > > The InMemoryTest passed, and the DatabaseTest failed. The
> > > exception
> > > > > > > > from the DatabaseTest was a type conversion, from int to
> product
> > > (or
> > > > > > > > maybe the other way around.) I was able to "fix" it though.
> In
> > > the
> > > > > > > > Fluent NHibernate code I changed the Query method on the
> > > Repository
> > > > > > > > class from:
> >
> > > > > > > > return _session.Linq<T>().Where(where).ToArray();
> >
> > > > > > > > to
> >
> > > > > > > > return _session.Linq<T>().Where(where.Compile()).ToArray();
> >
> > > > > > > > Now both tests pass. All of the unit tests in the Fluent
> > > NHibernate
> > > > > > > > project pass either way.
> >
>
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