var z = (from a in db.LOT
                         where (a.PURCHASE.FILIALID == new Guid("C328102B-4982-4704-8240-AFE0FAEE1FDA"))
                       && (a.PURCHASE.DATE_PURCHASE >= new DateTime(2012, 9, 6)) && (a.PURCHASE.DATE_PURCHASE <= DateTime.Now)
                select a.ID).Count();

SELECT 
[GroupBy1].[A1] AS [C1]
FROM ( SELECT 
	COUNT(1) AS [A1]
	FROM   (SELECT [Extent1].[PURCHASEID] AS [PURCHASEID]
		FROM  [dbo].[LOT] AS [Extent1]
		INNER JOIN [dbo].[PURCHASE] AS [Extent2] ON [Extent1].[PURCHASEID] = [Extent2].[ID]
		WHERE (cast('c328102b-4982-4704-8240-afe0faee1fda' as uniqueidentifier) = [Extent2].[FILIALID]) AND ([Extent2].[DATE_PURCHASE] >= convert(datetime2, '2012-09-06 00:00:00.0000000', 121)) ) AS [Filter1]
	INNER JOIN [dbo].[PURCHASE] AS [Extent3] ON [Filter1].[PURCHASEID] = [Extent3].[ID]
	WHERE [Extent3].[DATE_PURCHASE] <= (SysDateTime())
)  AS [GroupBy1]

CREATE TABLE [dbo].[t1](
	[ID] [int] NOT NULL,
	[SOME_DATA] [nchar](10) NULL,
 CONSTRAINT [PK_t1] PRIMARY KEY CLUSTERED 
(
	[ID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

GO

using System;
using System.Collections.Generic;
using System.Data.Entity.Infrastructure;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication3
{
    class Program
    {
        static void Main(string[] args)
        {
            using (var db = new DB1Entities())
            {
                db.t1.Add(new t1() { ID = 1 });
                db.t1.Add(new t1() { ID = 2 });

                db.SaveChanges();

                // В это время поьзователи изменяют колонку SOME_DATA
                // делают у себя Commit

                var q = from t in db.t1
                        select t;

                foreach (var t in q)
                    Console.WriteLine("{0}, {1}", t.ID, t.SOME_DATA);

                // Колонка в таком виде и осталась SOME_DATA = NULL, изменения не попали напечатает
                // 1,
                // 2,

                var t1Set = ((IObjectContextAdapter)db).ObjectContext.CreateObjectSet<t1>();

                // по умолчанию DbSet<> использует AppendOnly стратегию для Identity Map,
                // меняем эту стратегию (для отчетов самое то
                t1Set.MergeOption = System.Data.Objects.MergeOption.NoTracking; 

                q = from t in t1Set
                        select t;

                foreach (var t in q)
                    Console.WriteLine("{0}, {1}", t.ID, t.SOME_DATA);

                // Теперь изменения видны
                // 1, КПЦУП342Е
                // 2, D2N8YV482
            }
        }
    }
}

var q = from t in db.t1
                        select t;

var t1Set = ((IObjectContextAdapter)db).ObjectContext.CreateObjectSet<t1>();
// по умолчанию DbSet<> использует AppendOnly стратегию для Identity Map,
// меняем эту стратегию (для отчетов самое то
t1Set.MergeOption = System.Data.Objects.MergeOption.NoTracking; 

    public enum MergeOption
    {
        AppendOnly = 0,
        OverwriteChanges = 1,
        PreserveChanges = 2,
        NoTracking = 3,
    }

#region Assembly EntityFramework.dll, v5.0.0.0
// ...\EntityFramework.5.0.0\lib\net45\EntityFramework.dll
#endregion

using System.Data.Objects;

namespace System.Data.Entity.Infrastructure
{
    public interface IObjectContextAdapter
    {
        // Summary:
        //     Gets the object context.
        ObjectContext ObjectContext { get; }
    }
}