create table t2(id int, name nvarchar(20));
create table t1(id_t2 int, val int, tarid int);

insert into t2(id, name) values(1, 'name 1');
insert into t2(id, name) values(2 'name 2');

insert into t1(id_t2, val, tarid) values(1, 28, 1);
insert into t1(id_t2, val, tarid) values(1, 30, 2);
insert into t1(id_t2, val, tarid) values(1, 27, 3);
insert into t1(id_t2, val, tarid) values(1, 29, 4);
insert into t1(id_t2, val, tarid) values(2, 58, 1);
insert into t1(id_t2, val, tarid) values(2, 60, 2);
insert into t1(id_t2, val, tarid) values(2, 62, 3);
insert into t1(id_t2, val, tarid) values(2, 68, 4);

/* Написать хранимку, которая создает текст запроса ниже и выполняет его */
select t2.name, tmp.*
  from t2 left join
	   (
			  select id_t2,
					 /* Эти строчки текста запроса генерить динамически */
					 min(case tarid when 1 then val else null end) as val1,
					 min(case tarid when 2 then val else null end) as val2,
					 min(case tarid when 3 then val else null end) as val3,
					 min(case tarid when 4 then val else null end) as val4
				from t1
			group by id_t2
	   ) as tmp on t2.id = tmp.id_t2

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

namespace ConsoleApplication17
{
    class Program
    {
        static void Main(string[] args)
        {

            var esb = new EntityConnectionStringBuilder();
            esb.Metadata = @"res://*/Model1.csdl|res://*/Model1.ssdl|res://*/Model1.msl";
            esb.Provider = @"System.Data.SqlClient";
            esb.ProviderConnectionString = @"data source=LOCALHOST;initial catalog=DB1;integrated security=True;MultipleActiveResultSets=True;App=EntityFramework";

            using (var connection = new EntityConnection(esb.ConnectionString))
            {
                connection .Open();

                var esql = @"
                        select t2.id as Id, t2.name as Name, tmp.val1 as Val1, tmp.val2 as Val2, tmp.val3 as Val3, tmp.val4 as Val4
                          from DB1Entities1.t2 as t2 left join
	                           (
			                          select t1.id_t2,
					                         min(case when t1.tarid = 1 then t1.val else null end) as val1,
					                         min(case when t1.tarid = 2 then t1.val else null end) as val2,
					                         min(case when t1.tarid = 3 then t1.val else null end) as val3,
					                         min(case when t1.tarid = 4 then t1.val else null end) as val4
				                        from DB1Entities1.t1 as t1
			                        group by t1.id_t2
	                           ) as tmp on t2.id = tmp.id_t2
                    ";
                using (var command = new EntityCommand(esql, connection))
                {
                    var reader = command.ExecuteReader(System.Data.CommandBehavior.SequentialAccess);

                    while (reader.Read())
                    {
                        Console.WriteLine("{0}\t{1}\t{2}\t{3}\t{4}\t{5}", reader["Id"], reader["Name"],
                            reader["Val1"], reader["Val2"], reader["Val3"], reader["Val4"]);
                    }   
                }
            }
        }
    }
}

SELECT 
[Extent1].[id] AS [id], 
[Extent1].[name] AS [name], 
[GroupBy1].[A1] AS [C1], 
[GroupBy1].[A2] AS [C2], 
[GroupBy1].[A3] AS [C3], 
[GroupBy1].[A4] AS [C4]
FROM  [dbo].[t2] AS [Extent1]
LEFT OUTER JOIN  (SELECT 
	[Extent2].[K1] AS [K1], 
	MIN([Extent2].[A1]) AS [A1], 
	MIN([Extent2].[A2]) AS [A2], 
	MIN([Extent2].[A3]) AS [A3], 
	MIN([Extent2].[A4]) AS [A4]
	FROM ( SELECT 
		[Extent2].[id_t2] AS [K1], 
		CASE WHEN ([Extent2].[tarid] = 1) THEN [Extent2].[val] END AS [A1], 
		CASE WHEN ([Extent2].[tarid] = 2) THEN [Extent2].[val] END AS [A2], 
		CASE WHEN ([Extent2].[tarid] = 3) THEN [Extent2].[val] END AS [A3], 
		CASE WHEN ([Extent2].[tarid] = 4) THEN [Extent2].[val] END AS [A4]
		FROM [dbo].[t1] AS [Extent2]
	)  AS [Extent2]
	GROUP BY [K1] ) AS [GroupBy1] ON [Extent1].[id] = [GroupBy1].[K1]