SQL Serverデータ型からCLRデータ型へのマッピングを試す http://msdn.microsoft.com/ja-jp/library/ms131092.aspx

gistfile1.cs

using System;
using System.Collections.Generic;
using System.Data.SqlClient;
using System.Linq;
using System.Linq.Expressions;
using System.Text;

namespace ConsoleApp {
	class Program {
		private static SqlConnection Connect() {
			var builder = new SqlConnectionStringBuilder {
				DataSource = ".",
				InitialCatalog = "tempdb",
				IntegratedSecurity = true,
			};

			var connection = new SqlConnection(builder.ConnectionString);
			connection.Open();
			return connection;
		}

		public static void Main(string[] args) {
			var query = @"
select
	cast(1.1 as decimal) as [decimal],
	cast(0.1 as float) as [float],
	cast(1 as int) as [int],
	cast(1 as bigint) as [bigint],
	cast(1 as smallint) as [smallint],
	cast(1 as tinyint) as [tinyint],
	cast('2013-02-19' as date) as [date],
	cast('2013-02-19 20:00:00.1234567' as datetime2) as [datetime2],
	cast('20:00:00.1234567' as time) as [time],
	cast('a' as nchar) as [nchar],
	cast('abc' as nvarchar) as [nvarchar],
	cast('a' as binary) as [binary],
	cast('abc' as varbinary) as [varbinary],
	cast(1 as bit ) as [bit],
	newid() as [uniqueidentifier];";

			using(var connection = Connect())
			using(var command = new SqlCommand { CommandText = query, Connection = connection })
			using(var reader = command.ExecuteReader()) {
				Console.WriteLine("{0,-18}{1}", "SQL Server", "CLR");
				while(reader.Read()) {
					for(var index = 0; index < reader.FieldCount; index++) {
						Console.WriteLine("{0,-18}{1}", reader.GetName(index), reader.GetValue(index).GetType());
					}
				}
			}
/*
実行結果
SQL Server        CLR
decimal           System.Decimal
float             System.Double
int               System.Int32
bigint            System.Int64
smallint          System.Int16
tinyint           System.Byte
date              System.DateTime
datetime2         System.DateTime
time              System.TimeSpan
nchar             System.String
nvarchar          System.String
binary            System.Byte[]
varbinary         System.Byte[]
bit               System.Boolean
uniqueidentifier  System.Guid
*/
		}
	}
}