IAggregateFluentExtensionsSingleOrDefaultTResult 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: 2.18.0+554c799eb1ec8dd732f16c739387f6664df1ba7a

Syntax

Copy

public static TResult SingleOrDefault<TResult>(
	this IAggregateFluent<TResult> aggregate,
	CancellationToken cancellationToken = default
)

<ExtensionAttribute>
Public Shared Function SingleOrDefault(Of TResult) ( 
	aggregate As IAggregateFluent(Of TResult),
	Optional cancellationToken As CancellationToken = Nothing
) As TResult

[<ExtensionAttribute>]
static member SingleOrDefault : 
        aggregate : IAggregateFluent<'TResult> * 
        ?cancellationToken : CancellationToken 
(* Defaults:
        let _cancellationToken = defaultArg cancellationToken new CancellationToken()
*)
-> '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: TResult
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).

Reference

IAggregateFluentExtensions Class