[Expand]General Information
[Expand]WinForms Controls
[Expand]ASP.NET Controls and MVC Extensions
[Expand]ASP.NET Bootstrap Controls
[Expand]ASP.NET Core Bootstrap Controls
[Expand]WPF Controls
[Expand]Xamarin Controls
[Expand]Windows 10 App Controls
[Expand]Office File API
[Expand]Reporting
[Expand]Report and Dashboard Server
[Expand]Dashboard
[Expand]eXpressApp Framework
[Collapse]eXpress Persistent Objects
 [Expand]Product Information
 [Expand]Getting Started
 [Expand]Fundamentals
 [Expand]Feature Center
 [Expand]Concepts
 [Expand]Design-Time Features
 [Expand]Examples
 [Expand]Member Tables
 [Collapse]API Reference
  [Collapse]DevExpress.Xpo
   [Expand]AggregatedAttribute Class
   [Expand]AssociationAttribute Class
    AsyncBehavior Enumeration
    AsyncCommitCallback Delegate
    AsyncSelectDataCallback Delegate
    CacheBehavior Enumeration
    CollectionBindingBehavior Enumeration
   [Expand]ColumnDbDefaultValueAttribute Class
   [Expand]ColumnDefaultValueAttribute Class
   [Expand]CommitObjectStubsResult Class
   [Expand]CustomAttribute Class
   [Expand]CustomCriteriaManager Class
   [Expand]DataViewPropertiesCollection Class
   [Expand]DataViewProperty Class
   [Expand]DataViewRecord Class
   [Expand]DbTypeAttribute Class
    DefaultMembersPersistence Enumeration
   [Expand]DefaultMembersPersistenceAttribute Class
   [Expand]DeferredDeletionAttribute Class
   [Expand]DelayedAttribute Class
   [Expand]DisplayNameAttribute Class
   [Expand]ExplicitLoadingAttribute Class
   [Expand]ExplicitUnitOfWork Class
   [Expand]FetchOnlyAttribute Class
   [Expand]GetObjectStubsByKeyQuery Class
    GuidGenerationMode Enumeration
   [Expand]HiddenAttribute Class
   [Expand]ICustomCriteriaOperatorQueryable Interface
   [Expand]ICustomFunctionOperatorQueryable Interface
   [Expand]IDataLayer Interface
   [Expand]IDataLayerAsync Interface
    IdentityMapBehavior Enumeration
   [Expand]IndexedAttribute Class
   [Expand]IndicesAttribute Class
   [Expand]IObjectLayer Interface
   [Expand]IObjectLayerAsync Interface
   [Expand]IObjectLayerEx Interface
   [Expand]IObjectLayerOnSession Interface
   [Expand]ISerializableObjectLayer Interface
   [Expand]ISerializableObjectLayerEx Interface
   [Expand]IXPModificationsStore Interface
   [Expand]IXPObject Interface
   [Expand]IXPSimpleObject Interface
   [Expand]KeyAttribute Class
   [Expand]LoadDataMemberOrderItem Structure
    LockingOption Enumeration
   [Expand]MapInheritanceAttribute Class
    MapInheritanceType Enumeration
   [Expand]MapToAttribute Class
   [Expand]MemberDesignTimeVisibilityAttribute Class
   [Expand]MergeCollisionBehaviorAttribute Class
   [Expand]NestedUnitOfWork Class
   [Expand]NoForeignKeyAttribute Class
   [Expand]NonPersistentAttribute Class
   [Expand]NullableAttribute Class
    NullableBehavior Enumeration
   [Expand]NullableBehaviorAttribute Class
   [Expand]NullValueAttribute Class
   [Expand]ObjectChangeEventArgs Class
    ObjectChangeEventHandler Delegate
    ObjectChangeReason Enumeration
   [Expand]ObjectManipulationEventArgs Class
    ObjectManipulationEventHandler Delegate
   [Expand]ObjectsByKeyQuery Class
   [Expand]ObjectsManipulationEventArgs Class
    ObjectsManipulationEventHandler Delegate
   [Expand]ObjectsQuery Class
   [Expand]ObjectStubsQuery Class
   [Collapse]OptimisticLockingAttribute Class
     OptimisticLockingAttribute Members
    [Expand]OptimisticLockingAttribute Constructor
    [Expand]OptimisticLockingAttribute Properties
    OptimisticLockingBehavior Enumeration
   [Expand]OptimisticLockingIgnoredAttribute Class
    OptimisticLockingReadBehavior Enumeration
   [Expand]OptimisticLockingReadBehaviorAttribute Class
    OptimisticLockingReadMergeBehavior Enumeration
   [Expand]PersistentAliasAttribute Class
   [Expand]PersistentAttribute Class
   [Expand]PersistentBase Class
    PersistentCriteriaEvaluationBehavior Enumeration
   [Expand]ResolveSessionEventArgs Class
    ResolveSessionEventHandler Delegate
   [Expand]SchemaInitEventArgs Class
    SchemaInitEventHandler Delegate
   [Expand]SerializableObjectLayer Class
   [Expand]SerializableObjectLayerClient Class
    ServerExceptionThrownAction Enumeration
   [Expand]ServerExceptionThrownEventArgs Class
    ServerExceptionThrownEventHandler Delegate
   [Expand]ServerViewPropertiesCollection Class
   [Expand]ServerViewProperty Class
   [Expand]Session Class
   [Expand]SessionManipulationEventArgs Class
    SessionManipulationEventHandler Delegate
   [Expand]SessionObjectLayer Class
   [Expand]SessionOperationFailEventArgs Class
    SessionOperationFailEventHandler Delegate
   [Expand]SimpleDataLayer Class
   [Expand]SimpleObjectLayer Class
   [Expand]SizeAttribute Class
   [Expand]SkipCheckForFeedsAttribute Class
    SortDirection Enumeration
   [Expand]SortingCollection Class
   [Expand]StreamAttribute Class
   [Expand]ThreadSafeDataLayer Class
   [Expand]UnitOfWork Class
   [Expand]ValueConverterAttribute Class
   [Expand]ViewPropertiesCollection Class
   [Expand]ViewProperty Class
   [Expand]ViewRecord Class
   [Expand]VisibleAttribute Class
   [Expand]XPBaseCollection Class
   [Expand]XPBaseObject Class
   [Expand]XPBindingSource Class
   [Expand]XPClassInfoStub Class
   [Expand]XPCollection Class
   [Expand]XPCollection<T> Class
   [Expand]XPCollectionChangedEventArgs Class
    XPCollectionChangedEventHandler Delegate
    XPCollectionChangedType Enumeration
   [Expand]XPCursor Class
   [Expand]XPCustomObject Class
   [Expand]XPDataObject Class
   [Expand]XPDataView Class
   [Expand]XPDelayedProperty Class
   [Expand]XPDictionaryStub Class
   [Expand]XPInstantFeedbackSource Class
   [Expand]XPInstantFeedbackView Class
   [Expand]XPLiteObject Class
   [Expand]XPObject Class
   [Expand]XPObjectSource Class
   [Expand]XPObjectSourcePropertiesCollection Class
   [Expand]XPObjectSourceProperty Class
   [Expand]XPObjectSourceRecord Class
   [Expand]XPObjectStub Class
   [Expand]XPObjectStubCollection Class
   [Expand]XPObjectType Class
   [Expand]XpoDataSource Class
   [Expand]XpoDataSourceInsertedEventArgs Class
    XpoDataSourceInsertedEventHandler Delegate
   [Expand]XpoDefault Class
   [Expand]XPPageSelector Class
   [Expand]XPQuery<T> Class
   [Expand]XPQueryBase Class
   [Expand]XPQueryExtensions Class
   [Expand]XPServerCollectionSource Class
   [Expand]XPServerModeView Class
   [Expand]XPView Class
   [Expand]XPWeakReference Class
  [Expand]DevExpress.Xpo.DB
  [Expand]DevExpress.Xpo.DB.Helpers
  [Expand]DevExpress.Xpo.Exceptions
  [Expand]DevExpress.Xpo.Helpers
  [Expand]DevExpress.Xpo.Metadata
[Expand]CodeRush
[Expand]CodeRush Classic
[Expand]Cross-Platform Core Libraries
[Expand]Tools and Utilities
 End-User Documentation
View this topic on docs.devexpress.com (Learn more)

OptimisticLockingAttribute Class

Specifies that a persistent object's state can be locked during a session.

Namespace:DevExpress.Xpo
Assembly:DevExpress.Xpo.v19.1.dll

Expanded Syntax

Expanded Remarks

The OptimisticLockingAttribute attribute specifies whether a session can lock a persistent object's state (allows optimistic locking to be enabled). To control object locking for objects that have the object locking option enabled, a new system field called by default OptimisticLockField is added to the object table's structure during the database schema update.

In optimistic concurrency, locks are set and held only while the data store is being accessed. The locks prevent other users from attempting to update objects at the same time. When an update is attempted, the original version of a changed object is compared against the existing object in the data store. If the two are different, the update fails with a concurrency error. It is up to you at that point to reconcile the two objects using your business logic.

Use the Session.LockingOption property to control the persistent object's locking during a session.

Use the Session.TrackPropertiesModifications property to enable field-level locking.

For more information, see Optimistic Concurrency Control.

Note

This attribute affects service member generation (see When and Why XPO Extends the Database Schema). If it needs to be applied to a dynamically created class, pass this attribute in the XPDictionary.CreateClass method arguments instead of adding it afterwards.

Expanded Inheritance Hierarchy

System.Object
    System.Attribute
       OptimisticLockingAttribute

Expanded See Also

Is this topic helpful?​​​​​​​