Unconditional Delivery Listeners

The where clause argument in the addDeleteListener method is optional. When it is not provided, the real-time database will deliver any object  which is being deleted from the database's table:

Using Dictionary

var orderEventHandler = Backendless.Data.Of( "Order" ).RT();

orderEventHandler.AddDeleteListener( deletedOrder =>
{
  Console.WriteLine( $"an Order object has been deleted from the database. Object ID - {deletedOrder[ "objectId" ]}" );
} );

Custom Class

var orderEventHandler = Backendless.Data.Of<Order>().RT();

orderEventHandler.AddDeleteListener( deletedOrder =>
{
  Console.WriteLine( $"an Order object has been deleted from the database. Object ID - {deletedOrder.ObjectId}");
} );