IDataLayer Interface

The interface to which data access layers should conform.

Namespace: DevExpress.Xpo

Assembly: DevExpress.Xpo.v23.2.dll

NuGet Packages: DevExpress.Win.PivotGrid, DevExpress.Win.TreeMap, DevExpress.Xpo

NuGet Package: DevExpress.Xpo

Declaration

C#

public interface IDataLayer :
    IDisposable,
    IDataLayerProvider,
    IXPDictionaryProvider

VB.NET

Public Interface IDataLayer
    Inherits IDisposable,
             IDataLayerProvider,
             IXPDictionaryProvider

Related API Members

The following members return IDataLayer objects:

Show 14 links

Library	Related API Members
eXpressApp Framework	XPObjectSpaceProvider.DataLayer
eXpress Persistent Objects	SerializableObjectLayerClient.DataLayer
	Session.DataLayer
	SessionObjectLayer.DataLayer
	SimpleObjectLayer.DataLayer
	XpoDefault.DataLayer
	XpoDefault.GetDataLayer(AutoCreateOption)
	XpoDefault.GetDataLayer(IDbConnection, AutoCreateOption)
	XpoDefault.GetDataLayer(IDbConnection, XPDictionary, AutoCreateOption, out IDisposable[])
	XpoDefault.GetDataLayer(IDbConnection, XPDictionary, AutoCreateOption)
	XpoDefault.GetDataLayer(String, AutoCreateOption)
	XpoDefault.GetDataLayer(String, XPDictionary, AutoCreateOption, out IDisposable[])
	XpoDefault.GetDataLayer(String, XPDictionary, AutoCreateOption)
	XpoDefault.GetDataLayer(XPDictionary, AutoCreateOption)

Remarks

XPO provides the following IDataLayer implementations:

• SimpleDataLayer - used by default.
• ThreadSafeDataLayer.

In a general, SimpleDataLayer is equal to ThreadSafeDataLayer, and the substitution of one component by another has no effect. However, you cannot use SimpleDataLayer or ThreadSafeDataLayer under the circumstances described below:

• SimpleDataLayer does not support concurrent access from multiple threads. Use ThreadSafeDataLayer in multi-threaded applications and web applications where you share a data access layer between multiple users. Use ThreadSafeDataLayer if you use Instant Feedback data sources.
• ThreadSafeDataLayer implies that you never add new classes to XPDictionary or modify XPO metadata at runtime. You should add all required classes to XPDictionary before you create ThreadSafeDataLayer. You cannot dynamically create new classes/properties or add attributes after you instantiate a ThreadSafeDataLayer object.
• ThreadSafeDataLayer does not support database level transactions.

Extension Methods

Query<T>()