在sql2005无法插入记录

请教了：
我是初学者，我把源程序贴在下面，请各位老师帮我诊断，问题出在哪？
        SqlConnection conn = new SqlConnection("Data Source=SERVER\\SQL2005;Initial Catalog=toucherDB;Persist Security Info=True;User ID=sa;Password=sa123456");
        conn.Open();
        SqlCommand scd = new SqlCommand("select * from test", conn);
        try
        {
             = "insert into test(user_name,depa_info) values(@user_name,@depa_info)";
            SqlParameter para = new SqlParameter("@user_name", SqlDbType.VarChar, 50);
            para.Value = user_name;
            scd.Parameters.Add(para);
           
            para = new SqlParameter("@depa_info", SqlDbType.VarChar, 50);
            para.Value = depa_info;
            scd.Parameters.Add(para);
            scd.ExecuteNonQuery();
   整整一天了，我都没找出问题来。