EntityCollection<TEntity>::CreateSourceQuery Method ()
Returns an object query that, when it is executed, returns the same set of objects that exists in the current collection.
Assembly: System.Data.Entity (in System.Data.Entity.dll)
Return Value
Type: System.Data.Objects::ObjectQuery<TEntity>^An ObjectQuery<T> that represents the entity collection.
| Exception | Condition |
|---|---|
| InvalidOperationException | When the object is in an Added state. -or- When the object is in a Detached state with a MergeOption other than NoTracking. |
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.
This example is based on a modified version of the . 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.
Available since 3.5