SqlDataReader

Posted 2020-11-29 狠毒男孩

SqlDataReader

特点： 遍历整个数据，只读向一个方向读取一行行，

缺点： 不灵活，只能读取数据量少，并且一直占用连接

读取方式: Read()获取一行的数据,再次调用Read();方法

当调用Read()方法返回的False时，就不在表示有数据行。

创建方式
cmd.ExecuteReader()来创建。 cmd.ExecuteReader(CommandBehaviour.CloseConnection)---好处：关闭reader对象时，就自动关闭连接.

样式：

 public void ProcessRequest(HttpContext context)
        {
            List<Goods_date> goods_date = new List<Goods_date>();
            Mg_all<List<Goods_date>> obj = new Mg_all<List<Goods_date>>();
            string result = string.Empty;
            context.Response.ContentType = "text/plain";
           // string conStr = ConfigurationManager.ConnectionStrings["conStr"].ConnectionString;
            string ConnectionString = "数据库"; 
            mysqlConnection conn = new MySqlConnection(ConnectionString);
            conn.Open();
            //Goods_date goods_date = new Goods_date();
            string str1 = "Select * from tickets";
            MySqlCommand cmd = new MySqlCommand(str1,conn);
            MySqlDataReader dr = cmd.ExecuteReader();
            
            while (dr.Read())
            {

                goods_date.Add(new Goods_date { ID = dr.GetString(0),player=dr.GetString(1), officer = dr.GetString(2), time = dr.GetString(3), date = dr.GetString(4), amount = dr.GetString(5), paid = dr.GetString(6) });
            }
            dr.Close();
            dr.Dispose();
            obj.code ="0";
            obj.msg = "";
            obj.count = "10";
            obj.data = goods_date;
            result= new javascriptSerializer().Serialize(obj);
            context.Response.Write(result);
｝