AbstractEntityInstance Class

  • Article

Represents the base class for all entity instances in the Business Data Catalog. This is an abstract class and cannot be instantiated.

Inheritance Hierarchy

System.Object
  Microsoft.Office.Server.ApplicationRegistry.Runtime.AbstractInstance
    Microsoft.Office.Server.ApplicationRegistry.Runtime.AbstractEntityInstance
      Microsoft.Office.Server.ApplicationRegistry.SystemSpecific.Db.DbEntityInstance
      Microsoft.Office.Server.ApplicationRegistry.SystemSpecific.WebService.WebServiceEntityInstance

Namespace:  Microsoft.Office.Server.ApplicationRegistry.Runtime
Assembly:  Microsoft.SharePoint.Portal (in Microsoft.SharePoint.Portal.dll)

Syntax

'Declaration
<SharePointPermissionAttribute(SecurityAction.LinkDemand, ObjectModel := True)> _
<SharePointPermissionAttribute(SecurityAction.InheritanceDemand, ObjectModel := True)> _
Public MustInherit Class AbstractEntityInstance _
    Inherits AbstractInstance _
    Implements IEntityInstance

'Usage
Dim instance As AbstractEntityInstance

[SharePointPermissionAttribute(SecurityAction.LinkDemand, ObjectModel = true)]
[SharePointPermissionAttribute(SecurityAction.InheritanceDemand, ObjectModel = true)]
public abstract class AbstractEntityInstance : AbstractInstance, 
    IEntityInstance

Remarks

Conceptually, you can think of an entity instance in the Business Data Catalog as a single row of data returned from a back-end business application that has the ability to know which field (or fields in case of composite keys) in the row represents the identifier for the entity instance, and that enables you to call methods such as GetAssociatedInstances, GetIdentifierValues and Execute on that entity instance. In other words, an AbstractEntityInstance adds a persistent identity to the entity instances.

The system-specific DbEntityInstance and WebServiceEntityInstance classes inherit from this class. They represent one row of data from a database and a Web Service, respectively. However, you typically use the IEntityInstance and IEntityInstanceEnumerator objects to work with entity instances in the Business Data Catalog, as opposed to using the system specific implementations of these classes. This is because the IEntityInstance and IEntityInstanceEnumerator objects encapsulate the complexities of the underlying data sources, insulate you from having to learn application-specific coding paradigms, and allow clients to access all business applications in a single, simplified way.

Note

There are two places in the Business Data Catalog where you can execute code in a backend system: on the Entity, and on the instance of an Entity. These two methods of execution correspond to static and instance methods in C# or other object oriented programming languages. Calling .Execute on an Entity essentially requires the user to pass in parameters that mirror the underlying backend API. Calling .Execute on an instance of an Entity causes the Business Data Catalog to automatically plumb the value of the identifiers of the instance of the Entity into the appropriate slots in the backend API, eliminating the need for the end user to provide that information or set up those parameters.

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

See Also

Reference

AbstractEntityInstance Members

Microsoft.Office.Server.ApplicationRegistry.Runtime Namespace