c# - 如何使用多个主键表动态创建 DevExpress XPO？

Question

我在本主题中尝试示例 https://github.com/DevExpress-Examples/XPO_how-to-create-an-xpclassinfo-descendant-to-dynamically-build-a-persistent-class-structure-e1729

但它仅适用于单个主键表。所以我搜索了更多发现这个： https ://github.com/DevExpress-Examples/XPO_how-to-create-persistent-classes-mapped-to-tables-with-a-composite-primary-key-at-runtime-e4606

但是有很大的不同，我认为它不令人满意，因为它谈到了复合键（一个有很多列的键）所以我只需要一个从 SQL Server 表动态创建 XPO 的示例：我的表架构如下

然后 XPOCollectionSource 在服务器模式下绑定到网格……这就是我所需要的。

我使用的代码

XPServerCollectionSource GetServerModeSourceForTable(IDbConnection connection, string tableName) {  
    XPDictionary dict = new ReflectionDictionary();  
    XPClassInfo classInfo = dict.CreateClass(dict.QueryClassInfo(typeof(LiteDataObject)),  
        tableName);  
    DBTable[] tables = ((ConnectionProviderSql)XpoDefault.GetConnectionProvider(connection,  
        AutoCreateOption.None)).GetStorageTables(tableName);  
    foreach (DBColumn col in tables[0].Columns) {  
        XPMemberInfo member = classInfo.CreateMember(col.Name, DBColumn.GetType(  
            col.ColumnType));  
        if (tables[0].PrimaryKey.Columns.Contains(col.Name))  
            member.AddAttribute(new KeyAttribute());  
    }  
    return new XPServerCollectionSource(new Session(XpoDefault.GetDataLayer(  
        connection, dict, AutoCreateOption.None)), classInfo);  
}

乍看上去。如何使用XPServerCollectionSource动态创建的 XPO 对象。有两个主键。

score 0 · Accepted Answer

https://github.com/DevExpress-Examples/XPO_how-to-create-persistent-classes-mapped-to-tables-with-a-composite-primary-key-at-runtime-e4606/blob/19.2.7% 2B/CS/XpoConsoleApplication/XPComplexCustomMemberInfo.cs

这是一个必须使用的类。谁需要更多细节。我可以免费帮助他。

实现可以像：

[NonPersistent]
public class XPDynamicObject  : XPLiteObject
{
    public XPDynamicObject(Session session) : base(session) {}
    public XPDynamicObject(Session session, XPClassInfo classInfo) : base(session, classInfo) { }
}


       Button_Click or any event :

       XPDynamicObject.AutoSaveOnEndEdit = false;

        ReflectionDictionary dic = new ReflectionDictionary();
        var classInfo = dic.CreateClass(dic.GetClassInfo(typeof(XPDynamicObject)), "general.users");

        // WE MUST get schema from database .... via ConnectionProviderSql this is only way 
        var provider = XpoDefault.GetConnectionProvider(MSSqlConnectionProvider.GetConnectionString("(local)", "testdb"), AutoCreateOption.None) as ConnectionProviderSql;

        
        // Composite Key - this is only way to add composite key dynamically
        XPComplexCustomMemberInfo user_key = new 
        XPComplexCustomMemberInfo(classInfo, "user_key", typeof(object), new KeyAttribute(), new PersistentAttribute(), new BrowsableAttribute(false));
        user_key.AddSubMember("user_brn", typeof(int), new PersistentAttribute("user_brn"));
        user_key.AddSubMember("user_num", typeof(int), new PersistentAttribute("user_num"));

        var user_name = classInfo.CreateMember("user_name", typeof(string));
        user_name.AddAttribute(new PersistentAttribute("user_name"));
        

        dal = new SimpleDataLayer(dic, provider);

        XPServerCollectionSource xpServerCollectionSource = new XPServerCollectionSource(session, classInfo); // XPServerCollectionSource Only Editable server-mode datasource via ALlowNew, AllowEdit, AllowRemove properties

GridControl.DataSource = xpServerCollectionSource ;

完整备忘单（设计时和运行时 XPO）

对于按键或条件搜索对象，请使用以下命令：

编辑：2021-05-24

对于那些询问与复合键关联的人。这真是一场噩梦。默认情况下，Xpo 不提供。相反，您可以在子类中使用 Session.GetObjectByKey() 并在父类中使用新的 XPCollection。但实际上它有点慢，用人工钥匙的原生方式。

一目了然：使用人工/单键列以获得更好的任何 ORM 兼容性。否则以后在数据库中将是一场噩梦。例如，如果您支持另一个或替换当前的 ORM。

这是与复合键关联的代码。（请注意，您需要像上图那样动态转换它。您可能需要创建自定义 XPMemberInfo 并覆盖 GetValue() 以返回 Session.GetObjectByKey() 并创建新的 XPCollection。（真的很糟糕，最糟糕的事情是不支持曾经由 Xpo。所以复合键在技术上是不好的方法，除非您需要创建单个表将其绑定到网格。例如：-没有更多子表的 SalesOrderDetail 表）

[Persistent("users")]
public class user : XPLiteObject
{
    public user(Session session) : base(session) { }
    public user(Session session, XPClassInfo classInfo) : base(session, classInfo) { }

    [Key, Persistent]
    public user_key user_key { get; set; }
    [Persistent("user_name")]
    public string user_name { get; set; }

    private XPCollection<Trans> _trans;
    public XPCollection<Trans> trans
    {
        get
        {
            if (_trans == null)
                _trans = new XPCollection<Trans>(Session, CriteriaOperator.Parse($"user_brn = {user_key.user_brn} AND user_num = {user_key.user_num}"));
            return _trans;
        }
    }

}

public class Trans : XPLiteObject
{
    public Trans(Session session) : base(session) { }
    public Trans(Session session, XPClassInfo classInfo) : base(session, classInfo) { }

    [Key,Persistent("TransID")]
    public int TransID { get; set; }

    public int user_brn { get; set; }
    public int user_num { get; set; }

    public user user
    {
        get
        {
            var key = new user_key();
            key.user_brn = 1;
            key.user_num = 3;
            var obj = Session.GetObjectByKey<user>(key, true);
            return obj;
        }
    }
}

// Composite-Key
public struct user_key
{
    [Persistent("user_brn")]
    public int user_brn { get; set; }
    [Persistent("user_num")]
    public int user_num { get; set; }
}

上述模型的动态运行时版本：

    class XPCompositeAssociationMemberInfo : XPCustomMemberInfo
    {
        public XPCompositeAssociationMemberInfo(XPClassInfo owner, string propertyName, Type propertyType, XPClassInfo referenceType, bool nonPersistent, bool nonPublic) : base(owner, propertyName, propertyType, referenceType, nonPersistent, nonPublic)
        {
        }

        public override object GetValue(object theObject)
        {
            XPDynamicObject val = theObject as XPDynamicObject;
            if(val != null)
            {
                var user_num = val.GetMemberValue("user_num");
                IdList vals = new IdList();
                vals.Add(1);
                vals.Add(user_num);
                return val.Session.GetObjectByKey(ReferenceType, vals);
            }
            return val;
        }
    }


  XPDynamicObject.AutoSaveOnEndEdit = false;

        ReflectionDictionary dic = new ReflectionDictionary();
        var userClassInfo = dic.CreateClass(dic.GetClassInfo(typeof(XPDynamicObject)), "users");

        // WE MUST get schema from database .... via ConnectionProviderSql this is only way 
        var provider = XpoDefault.GetConnectionProvider(MSSqlConnectionProvider.GetConnectionString("(local)", "testdb"), AutoCreateOption.None) as ConnectionProviderSql;
        //DBTable Table = provider.GetStorageTables("users")[0];
        
        // Composite Key - this is only way to add composite key dynamically
        XPComplexCustomMemberInfo user_key = new XPComplexCustomMemberInfo(userClassInfo, "user_key", typeof(object), new KeyAttribute(), new PersistentAttribute(), new BrowsableAttribute(false));
        user_key.AddSubMember("user_brn", typeof(int), new PersistentAttribute("user_brn"));
        user_key.AddSubMember("user_num", typeof(int), new PersistentAttribute("user_num"));
        
        var user_name = userClassInfo.CreateMember("user_name", typeof(string));
        user_name.AddAttribute(new PersistentAttribute("user_name"));

        var transClassInfo = dic.CreateClass(dic.GetClassInfo(typeof(XPDynamicObject)), "Trans");
        var TransID = transClassInfo.CreateMember("TransID", typeof(int), new KeyAttribute());
        var user_brn = transClassInfo.CreateMember("user_brn", typeof(int));
        var user_num = transClassInfo.CreateMember("user_num", typeof(int));
        XPCompositeAssociationMemberInfo userMI = new XPCompositeAssociationMemberInfo(transClassInfo, "user", typeof(object), userClassInfo, true, false);



        dal = new SimpleDataLayer(dic, provider);            
        Session session = new Session(dal);
        XPServerCollectionSource xpServerCollectionSource = new XPServerCollectionSource(session, transClassInfo); // XPServerCollectionSource Only Editable server-mode datasource via ALlowNew, AllowEdit, AllowRemove properties                        
        xpServerCollectionSource.DisplayableProperties = "TransID;user.user_key.user_num;user.user_name";

最后，重要！

在任何 Xpo 中运行时实现 Composite-Keys 案例真的非常非常困难。而是替换为单列键（身份或人工。GUID 等）

score -1 · Accepted Answer

我不知道这是否是您想要的，但我将使用XPInstantFeedbackSource.

您可以在如何实施即时反馈模式 Xpo中获得更多信息

`XPLiteObject`LogXPO模型

[Persistent("log.t_log")]
public class LogXPOModel : XPLiteObject
{
    [Key, DevExpress.Xpo.DisplayName("id")]
    public long id { get; set; }

    [Key, DevExpress.Xpo.DisplayName("recv_time")]    
    public long recv_time

    ...
}

`Window`主窗口

public class MainWindow : Window
{
    public XPInstantFeedbackSource SqliteXPInstantFeedbackSource

    public MainWindow() {
        ...
        SqliteXPInstantFeedbackSource = new XPInstantFeedbackSource();
        SqliteXPInstantFeedbackSource.ObjectType = typeof(LogXPOModel);
        SqliteXPInstantFeedbackSource.ResolveSession += SqliteXPInstantFeedbackSource_ResolveSession;
        SqliteXPInstantFeedbackSource.DismissSession += SqliteXPInstantFeedbackSource_DismissSession;
        View.Grid.ItemsSource = SqliteXPInstantFeedbackSource;
    }
    
    ...
}

就像那样——我的桌子有两个钥匙；并且，它不会产生任何问题。

c# - 如何使用多个主键表动态创建 DevExpress XPO？

2 回答 2

XPLiteObjectLogXPO模型

Window主窗口

Related

Reference

`XPLiteObject`LogXPO模型

`Window`主窗口