Question

我需要在运行时使用Entity Framework进行连接和架构更改。

我尝试了以下代码：Post

我正在使用该代码：

        public EntityConnection SetCurrentEntityConnection(string schemaName, string databaseIPAddress, int databasePort, string userName, string password, string model)
    {
        XmlReader[] MappingReader = new XmlReader[] { XmlReader.Create(Assembly.GetExecutingAssembly().GetManifestResourceStream(model + ".msl")) };
        XmlReader[] ConceptualReader = new XmlReader[] { XmlReader.Create(Assembly.GetExecutingAssembly().GetManifestResourceStream(model + ".csdl")) };

        var StorageReader = XmlReader.Create(Assembly.GetExecutingAssembly().GetManifestResourceStream(model + ".ssdl"));
        XNamespace StorageNS = "http://schemas.microsoft.com/ado/2009/02/edm/ssdl";

        var StorageXml = XElement.Load(StorageReader);

        foreach (var EntitySet in StorageXml.Descendants(StorageNS + "EntitySet"))
        {
            var SchemaAttribute = EntitySet.Attributes("Schema").FirstOrDefault();
            if (SchemaAttribute != null)
                SchemaAttribute.SetValue(schemaName);
        }
        StorageXml.CreateReader();

        var Workspace = new MetadataWorkspace();
        StoreItemCollection StorageCollection = new StoreItemCollection(new XmlReader[] { StorageXml.CreateReader() });
        EdmItemCollection ConceptualCollection = new EdmItemCollection(ConceptualReader);
        StorageMappingItemCollection MappingCollection = new StorageMappingItemCollection(ConceptualCollection, StorageCollection, MappingReader);
        Workspace.RegisterItemCollection(ConceptualCollection);
        Workspace.RegisterItemCollection(StorageCollection);
        Workspace.RegisterItemCollection(MappingCollection);

        ///
        /// Adjust the connection string
        /// 
        var ConnectionData = new EntityConnectionStringBuilder();
        ConnectionData.Provider = "Oracle.ManagedDataAccess.Client";
        ConnectionData.Metadata = "metadata=res://*/Model.Model.csdl|res://*/Model.Model.ssdl|res://*/Model.Model.msl";
        ConnectionData.Name = "Entities";

        /// Build the connection string (using Oracle EZ Connection string)
        string conn = "data source=" + userName + "/" + password + "@" + databaseIPAddress + ":" + databasePort + "/" + schemaName ;

        ConnectionData.ProviderConnectionString = conn;


        var Connection = DbProviderFactories.GetFactory(ConnectionData.Provider).CreateConnection();
        Connection.ConnectionString = ConnectionData.ProviderConnectionString;

        new EntityConnection(Workspace, Connection);
    }

我遇到两个问题：

问题1： foreach循环找不到任何EntitySet来更改模式。

问题2：我不知道如何在我的EF应用程序中使用新创建的EntityConnection。我通常使用：

Entity dbContext = new Entity();

然后开始对我的dbContext进行查询，但我不知道如何处理EntityConnection以及应该如何处理它。那么，新创建的EntityConnection和原始DbContext之间的关系是什么。

顺便说一下，我正在使用DatabaseFirst for Oracle。 DMDX不会生成带有连接参数的实体构造函数。

感谢您的帮助。这让我发疯了......

实体框架架构和连接在运行时更改

0 个答案: