แก้ไข

แชร์ผ่าน

ObjectContext.Connection Property

  • Reference

Definition

Namespace:
System.Data.Objects
Assembly:
System.Data.Entity.dll

Gets the connection used by the object context.

public:
 property System::Data::Common::DbConnection ^ Connection { System::Data::Common::DbConnection ^ get(); };
public System.Data.Common.DbConnection Connection { get; }
member this.Connection : System.Data.Common.DbConnection
Public ReadOnly Property Connection As DbConnection

Property Value

DbConnection

A DbConnection object that is the connection.

Exceptions

ObjectDisposedException

When the ObjectContext instance has been disposed.

Examples

This example creates an EntityConnection object that is passed into the constructor of a long-running ObjectContext. The connection is opened manually. Both the EntityConnection object and the ObjectContext object are disposed of manually.

// Define the order ID for the order we want.
int orderId = 43680;

// Create an EntityConnection.
EntityConnection conn =
    new EntityConnection("name=AdventureWorksEntities");

// Create a long-running context with the connection.
AdventureWorksEntities context =
    new AdventureWorksEntities(conn);

try
{
    // Explicitly open the connection.
    if (conn.State != ConnectionState.Open)
    {
        conn.Open();
    }

    // Execute a query to return an order.
    SalesOrderHeader order =
        context.SalesOrderHeaders.Where(
        "it.SalesOrderID = @orderId", new ObjectParameter("orderId", orderId))
        .Execute(MergeOption.AppendOnly).First();

    // Change the status of the order.
    order.Status = 1;

    // You do not have to call the Load method to load the details for the order,
    // because  lazy loading is set to true
    // by the constructor of the AdventureWorksEntities object.
    // With  lazy loading set to true the related objects are loaded when
    // you access the navigation property. In this case SalesOrderDetails.

    // Delete the first item in the order.
    context.DeleteObject(order.SalesOrderDetails.First());

    // Save changes.
    if (0 < context.SaveChanges())
    {
        Console.WriteLine("Changes saved.");
    }

    // Create a new SalesOrderDetail object.
    // You can use the static CreateObjectName method (the Entity Framework
    // adds this method to the generated entity types) instead of the new operator:
    // SalesOrderDetail.CreateSalesOrderDetail(1, 0, 2, 750, 1, (decimal)2171.2942, 0, 0,
    //                                         Guid.NewGuid(), DateTime.Today));
    SalesOrderDetail detail = new SalesOrderDetail
    {
        SalesOrderID = 1,
        SalesOrderDetailID = 0,
        OrderQty = 2,
        ProductID = 750,
        SpecialOfferID = 1,
        UnitPrice = (decimal)2171.2942,
        UnitPriceDiscount = 0,
        LineTotal = 0,
        rowguid = Guid.NewGuid(),
        ModifiedDate = DateTime.Now
    };

    order.SalesOrderDetails.Add(detail);

    // Save changes again.
    if (0 < context.SaveChanges())
    {
        Console.WriteLine("Changes saved.");
    }
}
catch (InvalidOperationException ex)
{
    Console.WriteLine(ex.ToString());
}
finally
{
    // Explicitly dispose of the context and the connection.
    context.Dispose();
    conn.Dispose();
}

Remarks

This property returns the connection object that was passed into the constructor or created during construction. The connection's ownership is determined by the constructors used.

Applies to

See also