不久,
这是一个架构
用户表
类别表
- 用户有一个 categoryID
- 我只需要使用 User_ID、CategoryID、CategoryName填充 GridControl
- 注意 CategoryName 只属于第二个表(Category Table)
我所做的是:
创建模型(用户,类别)请注意,主键是复合的,因此它必须是结构 https://supportcenter.devexpress.com/ticket/details/a2615/xpo-how-to-map-persistent-objects-to-database-表与复合或复合多#
// Composite key must be a struct
public struct user_key
{
[Persistent("user_brn")]
public int user_brn { get; set; }
[Persistent("user_num")]
public int user_num { get; set; }
}
[Persistent("Users")]
public class User : XPLiteObject
{
public User(Session session) : base(session) { }
[Key, Persistent]
public user_key key; // user_brn, user_num
[Persistent("user_name")]
public string user_name { get; set; }
[Persistent("CategoryID")]
public int CategoryID { get; set; }
[NonPersistent, Association("user_category")]
public Category Category
{
get; set;
}
[PersistentAlias("Category.CategoryName")]
public string CategoryName { get; set; } // I think it will work. But it doesn't
}
[Persistent("Category")]
public class Category : XPLiteObject
{
public Category(Session session) : base(session) { }
[Key, Persistent("CategoryID")]
public int CategoryID { get; set; }
[Persistent("CategoryName")]
public string CategoryName { get; set; }
private User _user;
[NonPersistent, Association("user_category")]
public User User { get; set; }
}
网格视图代码
IDataLayer dal =
XpoDefault.GetDataLayer(MSSqlConnectionProvider.GetConnectionString("
(local)", "testdb"), AutoCreateOption.DatabaseAndSchema);
Session session = new Session(dal);
XPCollection collection = new XPCollection(session, typeof(User));
gridControl1.DataSource = collection;
结果:=失败
我该做什么?任何帮助