IDataLayer Interface

The interface to which data access layers should conform.

Namespace: DevExpress.Xpo

Assembly: DevExpress.Xpo.v21.1.dll

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)

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)

Related API Members

The following members return IDataLayer objects:

• XPObjectSpaceProvider.DataLayer

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.

Related GitHub Examples

The following code snippets (auto-collected from DevExpress Examples) contain references to the IDataLayer interface.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

C#

XPO_how-to-import-a-large-data-set-using-xpo-efficiently-within-a-transaction-t333879/CS/XpoImport/XpoImportHelper.cs#L12

public abstract class XpoImportHelper {
    private IDataLayer dataLayer;
    private ICommandChannel commandChannel;

XPO_how-to-read-and-manipulate-xpo-objects-stored-in-multiple-databases-simultaneously-t475838/CS/ConsoleApplication/Program.cs#L13

static IDataLayer DB1dal;
static IDataLayer DB2dal;

how-to-bind-an-aspnet-mvc-gridview-extension-to-a-table-with-an-unknown-schema-using-custo-t602001/CS/XPCustomBindingExample/XPO/StartupHelper.cs#L15

XPDictionary dict = DatabaseSchemaHelper.GetDefaultDatabaseSchema();
IDataLayer dal = XpoDefault.GetDataLayer(conn, dict, AutoCreateOption.DatabaseAndSchema);
UnitOfWork uow = new UnitOfWork(dal);

XPO_how-to-generate-a-sequential-number-for-a-business-object-within-a-database-transaction-e2620/CS/ExplicitUnitOfWorkDemo/SequenceGenerator.cs#L13

private Sequence seq;
public SequenceGenerator(IDataLayer dataLayer) {
    euow = new ExplicitUnitOfWork(dataLayer);

how-to-display-and-edit-many-to-many-objects-from-xpo-xpview-e243/CS/EditManyToMany/XpoHelper.cs#L25

static IDataLayer fDataLayer;
static IDataLayer DataLayer {

VB.NET

XPO_how-to-generate-a-sequential-number-for-a-business-object-within-a-database-transaction-e2620/VB/ExplicitUnitOfWorkDemo/SequenceGenerator.vb#L15

Private seq As Sequence
Public Sub New(ByVal dataLayer As IDataLayer)
    euow = New ExplicitUnitOfWork(dataLayer)

XPO_how-to-import-a-large-data-set-using-xpo-efficiently-within-a-transaction-t333879/VB/XpoImport/XpoImportHelper.vb#L12

Public MustInherit Class XpoImportHelper
    Private dataLayer As IDataLayer
    Private commandChannel As ICommandChannel

XPO_how-to-read-and-manipulate-xpo-objects-stored-in-multiple-databases-simultaneously-t475838/VB/ConsoleApplication/Program.vb#L13

Private Shared DB1dal As IDataLayer
Private Shared DB2dal As IDataLayer

how-to-bind-an-aspnet-mvc-gridview-extension-to-a-table-with-an-unknown-schema-using-custo-t602001/VB/XPCustomBindingExample/XPO/StartupHelper.vb#L19

Dim dict As XPDictionary = DatabaseSchemaHelper.GetDefaultDatabaseSchema()
Dim dal As IDataLayer = XpoDefault.GetDataLayer(conn, dict, AutoCreateOption.DatabaseAndSchema)
Dim uow As New UnitOfWork(dal)

how-to-display-and-edit-many-to-many-objects-from-xpo-xpview-e243/VB/EditManyToMany/XpoHelper.vb#L28

Private Shared fDataLayer As IDataLayer
Private Shared ReadOnly Property DataLayer() As IDataLayer

Extension Methods

Query<T>()