请问sql server2000中的数据类型与c#中的数据类型一一对应问题！

private string ChangeToCSharpType(string type)
{
string reval=string.Empty;
switch(type.ToLower())
{
case "int":
reval= "int";
break;
case "text":
reval= "string";
break;
case "bigint":
reval= "int";
break;
case "binary":
reval= "System.Byte";
break;
case "bit":
reval= "System.bit";
break;
case "char":
reval= "string";
break;
case "datetime":
reval= "System.DateTime";
break;
case "decimal":
reval= "System.Decimal";
break;
case "float":
reval= "System.Decimal";
break;
case "image":
reval= string.Empty;
break;
case "money":
reval= string.Empty;
break;
case "nchar":
reval= "string";
break;
case "ntext":
reval= "string";
break;
case "numeric":
reval= "System.Decimal";
break;
case "nvarchar":
reval= "string";
break;
case "real":
reval= string.Empty;
break;
case "smalldatetime":
reval= "System.DateTime";
break;
case "smallint":
reval= "int";
break;
case "smallmoney":
reval= string.Empty;
break;
case "timestamp":
reval= string.Empty;
break;
case "tinyint":
reval= "int";
break;
case "uniqueidentifier":
reval= string.Empty;
break;
case "varbinary":
reval= "string";
break;
case "varchar":
reval= "string";
break;
default:
reval= "string";
break;
}

需要这个样一个方法，传进来的是数据库中的数据类型，然后返回一个c#中的数据类型，但有一些我不知道如何对应，高手帮忙一下啊！ 返回string.Empty的就是不知道的