asp.net3.5读取数据库最优方案解决方法

try                {                    con.Open();                    com = new SqlCommand("select a,b from 个人资料 where  a=@a and b=@b", con);                    com.Parameters.Add("@a", SqlDbType.NVarChar, 50);                    com.Parameters.Add("@b", SqlDbType.NVarChar, 50);                    com.Parameters["@a"].Value = txtUser.Text;                    com.Parameters["@b"].Value = txtPwd.Text;                    SqlDataReader reader = com.ExecuteReader();                    if (reader.Read())                    {                        ....                    }                                       con.Close();                }                catch (Exception exx)                {                }                finally                {                    con.Close();                }