用简单的修改数据理解三层概念

public List<TableModel> GetDataList()
{
List<TableModel> models;
SqlHelper sqlhelper = new SqlHelper();
string sql = "select * from MyOrders";
using (SqlDataReader reader = sqlhelper.ExecuteReader(sql, null))
{
if (reader.HasRows)
{
models = new List<TableModel>();
while (reader.Read())
{
TableModel model = new TableModel();
model.ID = int.Parse(reader[0].ToString());
model.Name = reader[1].ToString();
model.Number = reader[2].ToString();
model.Count = reader.IsDBNull(3) ? null : (int?)reader.GetInt32(3);
model.Price = reader.GetInt32(4);
model.Purchaser = reader.IsDBNull(5) ? string.Empty : reader.GetString(5);
model.DateTime = reader.IsDBNull(6) ? null : (DateTime?)reader.GetDateTime(6);
model.Salesman = reader.IsDBNull(7) ? string.Empty : reader[7].ToString();
models.Add(model);
}
return models;
}
}
return null;
}

TableModel.cs

public class TableModel
{
/// <summary>
/// 数据模型:
///     像DataGridView一样的数据绑定控件,只认识属性(Model中的属性名称),
/// 不识别(认)字段。与表中的列的名称不是一回事.但是可以获得表中的列名，
/// 并设置在DataGridView中的列名上。
/// </summary>
public TableModel()
{

}
/// <summary>
/// id
/// </summary>
public int ID { get; set; }
/// <summary>
/// 商品名称
/// </summary>
public string Name { get; set; }
/// <summary>
/// 商品编号
/// </summary>
public string Number { get; set; }
/// <summary>
/// 销售数量
/// </summary>
public int? Count { get; set; }
/// <summary>
/// 销售价格
/// </summary>
public int Price { get; set; }
/// <summary>
/// 购买人
/// </summary>
public string Purchaser { get; set; }
/// <summary>
/// 销售日期
/// </summary>
public DateTime? DateTime { get; set; }
/// <summary>
/// 销售员
/// </summary>
public string Salesman { get; set; }
}