static void Main(string[] args)

        {

            Console.WriteLine("输入用户编号：");

            string cusernum = Console.ReadLine();

            Console.WriteLine("输入用户名：");

            string cusername = Console.ReadLine();

            string connString = @"Data Source=.; Initial Catalog=lh0216; User ID=sa;pwd=Founder123";

            //出了using括号objConnection类会被自动释放

            using (SqlConnection objConnection = new SqlConnection(connString))

            {

                objConnection.Open();

                using (SqlCommand objCmd = objConnection.CreateCommand())

                {

                    objCmd.CommandText = "select * from TBZG where czgbh='" + cusernum + "'" ;

                    using (SqlDataReader objReader = objCmd.ExecuteReader())

                    {

                        //结果集不为空

                        if (objReader.Read())

                        {

                            string cValue = objReader.GetString(objReader.GetOrdinal("czgxm"));

                            //检查手工输入的姓名与数据库中查询的名称是否相同

                            if (cValue == cusername)

                            {

                                Console.WriteLine("你好{0}",cusername);

                            }

                        }

                        else

                        {

                            Console.WriteLine("用户名不存在。");

                        }

                    }

                }

            }

            Console.ReadKey();

        }