Binding using nhibernate

[mary]

If using NHibernate and the grid's default binding, and the Model is set to:

public IEnumerable<T> Get()  
{  
    return Session.CreateCriteria(typeof(T)).Future<T>();  
} 

will this give a similar result as a linq query which defers the full results, so only one page will be fetched at a time?

thanks!

[Atanas Korchev]

Hi mary,

No, I don't think this will work the way you suggested. Our expression engine will try to pass an expression to a linq provider which you are not using (instead using the criteria API of NH). I may suggest you try Linq to NHibernate for making the queries. Unfortunately there are known issues with the Linq2Nhibernate provider - it still does not support all kinds of expressions. For example filtering in the Grid does not work. Until this is fixed we cannot properly support filtering unless we patch our expression engine to work with Nhibernate's linq provider. The good news is that the aforementioned provider is being updated to have better support for expressions.

As a workaround you can use custom binding as shown in this example. The interesting part is in the controller.

Regards,
Atanas Korchev
the Telerik team

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[Psycho Nelo]

I've tried to use Linq2Nhibernate provider and it does support filter expressions, for example .Where( x => x.Id = 1)

[Sam]

Are there any updates on this?

[Atanas Korchev]

Hi Sam,

 Filtering seems to work now with NHibernate 3.0. However grouping doesn't work. Nhibernate cannot execute the grouping query which is generated by the grid:

var orders = MvcApplication.NorthwindSession.Query<Order>();

orders.OrderBy(i => i.ShippedDate)
      .Take(10)
      .GroupBy(i => i.ShippedDate)
      .ToList();

I created a code library entry  which shows the Telerik MVC Grid bound to NHibernate (using FluentNHibernate) and LINQ. Paging, filtering and sorting should work as expected.

Regards,
Atanas Korchev
the Telerik team