ObjectQuery<T>.Include(String) Method
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Specifies the related objects to include in the query results.
public:
System::Data::Objects::ObjectQuery<T> ^ Include(System::String ^ path);
public System.Data.Objects.ObjectQuery<T> Include (string path);
member this.Include : string -> System.Data.Objects.ObjectQuery<'T>
Public Function Include (path As String) As ObjectQuery(Of T)
- path
- String
Dot-separated list of related objects to return in the query results.
A new ObjectQuery<T> with the defined query path.
path
is null
.
path
is empty
.
using (AdventureWorksEntities context =
new AdventureWorksEntities())
{
// Define an object query with a path that returns
// orders and items for a specific contact.
Contact contact =
context.Contacts.Include("SalesOrderHeaders.SalesOrderDetails")
.FirstOrDefault();
// Execute the query and display information for each item
// in the orders that belong to the first contact.
foreach (SalesOrderHeader order in contact
.SalesOrderHeaders)
{
Console.WriteLine(String.Format("PO Number: {0}",
order.PurchaseOrderNumber));
Console.WriteLine(String.Format("Order Date: {0}",
order.OrderDate.ToString()));
Console.WriteLine("Order items:");
foreach (SalesOrderDetail item in order.SalesOrderDetails)
{
Console.WriteLine(String.Format("Product: {0} "
+ "Quantity: {1}", item.ProductID.ToString(),
item.OrderQty.ToString()));
}
}
}
Query paths can be used with Entity SQL and LINQ queries.
Paths are all-inclusive. For example, if an include call indicates Include("Orders.OrderLines")
, not only will OrderLines
be included, but also Orders
. For more information, see Loading Related Objects.
When you call the Include method, the query path is only valid on the returned instance of the ObjectQuery<T>. Other instances of ObjectQuery<T> and the object context itself are not affected.
Because the Include method returns the query object, you can call this method multiple times on an ObjectQuery<T> to specify multiple paths for the query, as in the following example:
// Create a SalesOrderHeader query with two query paths,
// one that returns order items and a second that returns the
// billing and shipping addresses for each order.
ObjectQuery<SalesOrderHeader> query =
context.SalesOrderHeaders.Include("SalesOrderDetails").Include("Address");
Product | Versions |
---|---|
.NET Framework | 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
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