EF4: LINQ 2 Entities query works in C# but not in VB

Question

[EDITED: I left the original question below, with some more context and code to reproduce the problem. The short version below contains the essence of the question]

Shor

Answer 1

hi this can be made to work quite easy...

Instead of an IQueryable

Dim orders As IQueryable(Of Order) = db.Orders

use a List

Dim orders as List(of Order) = db.Orders.ToList()

Answer 2

Does this work?

    Dim a = From p In products Join o In orders On p.Id Equals o.ProductId
            Order By p.DateCreated
            Select New With {.id = p.Id, .OrderDate = o.OrderDate, .CustomerId = o.CustomerId, .DateCreated = p.DateCreated}

    Dim b = From outerOrder In orders _
            Where outerOrder.OrderDate = currentDate _
            AndAlso outerOrder.ProductId = _
            (From x In a Where x.OrderDate = outerOrder.OrderDate _
             AndAlso x.CustomerId = outerOrder.CustomerId _
             Select x.id).FirstOrDefault

Answer 3

Moving the Order By p.DateCreated line as per my edited answer allows the query to run without any exceptions. However, the emitted SQL is different so I don't think you are getting back the correct result.

Dim qLinq = From outerOrder In orders
            Let id = (From p In products 
                      Order By p.DateCreated
                      Join o In orders On p.Id Equals o.ProductId
                      Where o.OrderDate = outerOrder.OrderDate AndAlso
                            outerOrder.CustomerId = o.CustomerId
                      Select p.Id).FirstOrDefault()
            Where outerOrder.OrderDate = currentDate AndAlso
                  outerOrder.ProductId = id
            Select outerOrder

Answer 4

I think the following works, the SQL is ugly though:

Dim qLinq = From outerOrder In orders
                Where outerOrder.OrderDate = currentDate AndAlso
                outerOrder.ProductId =
                    (From x In (From p In products
                                 Join o In orders On p.Id Equals o.ProductId
                                 Where o.OrderDate = outerOrder.OrderDate AndAlso
                                        outerOrder.CustomerId = o.CustomerId
                                 Select p.Id)
                    Order By x).FirstOrDefault()
                Select outerOrder