EntityQuery<TEntity> Class
[WCF RIA Services Version 1 Service Pack 2 is compatible with either .NET framework 4 or .NET Framework 4.5, and with either Silverlight 4 or Silverlight 5.]
Represents a LINQ query over a collection of entities.
System.ServiceModel.DomainServices.Client.EntityQuery
System.ServiceModel.DomainServices.Client.EntityQuery<TEntity>
Namespace: System.ServiceModel.DomainServices.Client
Assembly: System.ServiceModel.DomainServices.Client (in System.ServiceModel.DomainServices.Client.dll)
The EntityQuery<TEntity> type exposes the following members.
| Name | Description | |
|---|---|---|
![]() | DomainClient | Gets the DomainClient for this query. (Inherited from EntityQuery.) |
![]() | EntityType | Gets the type this query retrieves data from. (Inherited from EntityQuery.) |
![]() | HasSideEffects | Gets a value indicating whether the query has side-effects. (Inherited from EntityQuery.) |
![]() | IncludeTotalCount | Gets or sets a value indicating whether the TotalEntityCount property is required. (Inherited from EntityQuery.) |
![]() | IsComposable | Gets a value indicating if the query supports composition. (Inherited from EntityQuery.) |
![]() | Parameters | Gets the parameters required by the query method. (Inherited from EntityQuery.) |
![]() | Query | Gets the underlying IQueryable for the query. (Inherited from EntityQuery.) |
![]() | QueryName | Gets the name of the query method. (Inherited from EntityQuery.) |
| Name | Description | |
|---|---|---|
![]() | OrderBy<TEntity, TKey> | Applies the specified ascending order clause to the source query. (Defined by EntityQueryable.) |
![]() | OrderByDescending<TEntity, TKey> | Applies the specified descending order clause to the source query. (Defined by EntityQueryable.) |
![]() | Select<TEntity> | Applies the specified selection to the source query. (Defined by EntityQueryable.) |
![]() | Skip<TEntity> | Applies the specified skip clause to the source query. (Defined by EntityQueryable.) |
![]() | Take<TEntity> | Applies the specified take clause to the source query. (Defined by EntityQueryable.) |
![]() | ThenBy<TEntity, TKey> | Applies the specified ascending order clause to the source query. (Defined by EntityQueryable.) |
![]() | ThenByDescending<TEntity, TKey> | Applies the specified descending order clause to the source query. (Defined by EntityQueryable.) |
![]() | Where<TEntity> | Applies the specified filter to the source query. (Defined by EntityQueryable.) |
In your client application, you can apply additional filtering on a query to limit which entities are returned. You use LINQ and a subset of LINQ query operators to modify the results returned from the query. The following lists the available query operators:
Where
OrderBy
ThenBy
Skip
Take
After you apply additional filtering, you pass the EntityQuery<TEntity> object as a parameter in the Load method to execute the query and get the results. If the query has a QueryAttribute with the IsComposable property set to false, you cannot apply additional filtering on the query. Generally, only queries that return a single entity will have IsComposable set to false.
The following code shows how to retrieve customers from the domain service. It filters customers who have phone numbers that start with 583 and orders them alphabetically by LastName. The results are displayed in a DataGrid.
public partial class MainPage : UserControl { private CustomerDomainContext _customerContext = new CustomerDomainContext(); public MainPage() { InitializeComponent(); EntityQuery<Customer> query = from c in _customerContext.GetCustomersQuery() where c.Phone.StartsWith("583") orderby c.LastName select c; LoadOperation<Customer> loadOp = this._customerContext.Load(query); CustomerGrid.ItemsSource = loadOp.Entities; } }
