EntityCollection<TEntity>.CreateSourceQuery Method
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Returns an object query that, when it is executed, returns the same set of objects that exists in the current collection.
public:
System::Data::Objects::ObjectQuery<TEntity> ^ CreateSourceQuery();public System.Data.Objects.ObjectQuery<TEntity> CreateSourceQuery ();override this.CreateSourceQuery : unit -> System.Data.Objects.ObjectQuery<'Entity (requires 'Entity : null and 'Entity :> System.Data.Objects.DataClasses.IEntityWithRelationships)>override this.CreateSourceQuery : unit -> System.Data.Objects.ObjectQuery<'Entity (requires 'Entity : null)>Public Function CreateSourceQuery () As ObjectQuery(Of TEntity)Returns
An ObjectQuery<T> that represents the entity collection.
Exceptions
When the object is in an Added state.
-or-
When the object is in a Detached state with a MergeOption other than NoTracking.
Examples
This example is based on a modified version of the School Model. This version supports table-per-type inheritance with Course as an abstract type. Complete the walkthrough to modify the School model to support the table-per-type inheritance example used in this topic.
This example shows how to use CreateSourceQuery to filter objects in an EntityCollection<TEntity> and bind only to objects of a specific type. For a complete version of this example, see How to: Bind Controls to Derived Types.
Remarks
This property is used to obtain a new instance of ObjectQuery<T> that returns the same set of objects. This is useful as the starting point for a more complex join, union, or filtered query, or to return the same objects in a detached state by using the NoTracking option.
CreateSourceQuery is used to filter objects in an EntityCollection<TEntity> to enable you to bind only objects of a specific type. For more information, see Binding Objects to Controls.
