oracle odp.net 32位/64位版本的问题

using System;
using Oracle.DataAccess.Client;

namespace test
{
    class Program
    {
        static void Main(string[] args)
        {
            //建议用这种风格的连接字符串，可以不用依赖于listener.ora文件中的配置
            string _connString = "Data Source=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=127.0.0.1)(PORT=1521)))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=orcl)));User Id=scott;Password=tiger;";

            using (OracleConnection conn = new OracleConnection(_connString))
            {
                string sql = "select * from emp t where mgr=:mgr";
                OracleCommand cmd = new OracleCommand(sql, conn);
                conn.Open();
                cmd.Parameters.Add(new OracleParameter() { ParameterName="mgr",Value="7839" });
                OracleDataReader dr =  cmd.ExecuteReader();
                while (dr.Read())
                {
                    Console.WriteLine("empno:{0}，ename:{1}，mgr:{2}", dr["empno"], dr["ename"],dr["mgr"]);
                }
                dr.Close();
            }

            Console.Read();
        }
    }
}