Query translator produces invalid results for queries that use groupby

[KevinRansom]

Opened at CodePlex by: latkin

In F# queries with groupBy clauses, invalid query translation can occur.

Repro: Download bmovie-data.mdf from F# 3.0 Sample Pack, path OtherSamples\BMovieMadness\CSharpMvcApp\App_Data\bmovie-data.mdf

Run the following in script or console app

#r "FSharp.Data.TypeProviders"
#r "System.Data.Entity"

[<Literal>]
let connectionString = @"Data Source=(LocalDb)\v11.0;Initial Catalog=bmovie-data;Integrated Security=SSPI;AttachDBFilename=D:\en\fs3sample\OtherSamples\BMovieMadness\CSharpMvcApp\App_Data\bmovie-data.mdf"
type internal T = Microsoft.FSharp.Data.TypeProviders.SqlEntityConnection<ConnectionString = connectionString, ForceUpdate=false>

open System.Linq

let internal db = T.GetDataContext()
let userIds = [| System.Guid() |]

let topGenres = query {
    for u in db.Users do
    where (userIds.Contains u.UserId)
    for g in u.UserGenres do
    groupBy (g.GenreId) into gr
    let k = gr.Count()
    sortBy k
    select gr.Key
    }
topGenres |> Seq.take 1 |> Seq.toArray

Result: System.NotSupportedException: Only parameterless constructors and initializers are supported in LINQ to Entities.