C# 编写SQL SERVER 2005 的存储过程

以下是一个查询IP地址归属地的CLR存储过程，三步：
1、用C#来做DLL，代码如下：
//====================================================================
using System;
using System.Collections.Generic;
using System.Text;
using System.Data.SqlTypes;
using System.Data.SqlClient;
using Microsoft.SqlServer.Server;
public class AddrInfo
{
    [Microsoft.SqlServer.Server.SqlProcedure]
    public static void getAddrInfo(SqlString ip, out SqlString info)
    {
        using (SqlConnection connection = new SqlConnection("context connection=true"))
        {
            //IP地址转为数字
            string[] tmp = ip.Value.Split(new string[]{"."},StringSplitOptions.None);
            Int64 ipn = ToInt(ToBinary(tmp[0]) + ToBinary(tmp[1]) + ToBinary(tmp[2]) + ToBinary(tmp[3]));
            connection.Open();
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = connection;
            cmd.CommandType = System.Data.CommandType.Text;
            cmd.CommandText = "select addr_info from CZIP where ipn1<="
                                + ipn.ToString() + " and ipn2>="