IAggregateFluentExtensionsSingleOrDefaultAsyncTResult Method |
Returns the only document of the aggregate result, or the default value if the result set is empty. Throws an exception if the result set contains more than one document.
Namespace:
MongoDB.Driver
Assembly:
MongoDB.Driver (in MongoDB.Driver.dll) Version: 2.8.0+cc573f3e1f48f39162b4b680e921a623e127e8fa
Syntax public static Task<TResult> SingleOrDefaultAsync<TResult>(
this IAggregateFluent<TResult> aggregate,
CancellationToken cancellationToken = null
)
<ExtensionAttribute>
Public Shared Function SingleOrDefaultAsync(Of TResult) (
aggregate As IAggregateFluent(Of TResult),
Optional cancellationToken As CancellationToken = Nothing
) As Task(Of TResult)
[<ExtensionAttribute>]
static member SingleOrDefaultAsync :
aggregate : IAggregateFluent<'TResult> *
?cancellationToken : CancellationToken
(* Defaults:
let _cancellationToken = defaultArg cancellationToken null
*)
-> Task<'TResult>
Parameters
- aggregate
- Type: MongoDB.DriverIAggregateFluentTResult
The aggregate. - cancellationToken (Optional)
- Type: System.ThreadingCancellationToken
The cancellation token.
Type Parameters
- TResult
- The type of the result.
Return Value
Type:
TaskTResult
The fluent aggregate interface.
Usage Note
In Visual Basic and C#, you can call this method as an instance method on any object of type
IAggregateFluentTResult. When you use instance method syntax to call this method, omit the first parameter. For more information, see
Extension Methods (Visual Basic) or
Extension Methods (C# Programming Guide).
See Also