private void button1_Click(object sender, EventArgs e)

        {            

            //建立Sql查询语句

            string sql = "select * from raifu";

            //创建SQL命令行对象

            SqlCommand  cmd= new SqlCommand(sql,sqlCon);

            //执行命令行对象           

            SqlDataReader odr = cmd.ExecuteReader(CommandBehavior.CloseConnection);

            IList<UserInfo> users = new List<UserInfo>();

            while (odr.Read())

            {

                UserInfo user = new UserInfo();

                user.UserID = Convert.ToInt32(odr["id"]);

                user.UserName = Convert.ToString(odr["name"]);

                user.UserAge = Convert.ToString(odr["age"]);

                users.Add(user);

            }

            

            dataGridView1.Columns["col1"].DataPropertyName = "UserID";

            dataGridView1.Columns["col2"].DataPropertyName = "UserName";

            dataGridView1.Columns["col3"].DataPropertyName = "UserAge";

            //绑定DataGridView控件

            dataGridView1.DataSource = users;

            //odr.Close();

        }

//插入数据

        private void button2_Click(object sender, EventArgs e)

        {

            //建立Sql语句

            string sql = "insert into raifu (1003,'Jerry','30');";

            //创建SQL命令行对象

            SqlCommand cmd = new SqlCommand(sql, sqlCon);

            //执行命令行对象         &