IAggregateFluentExtensions.FirstOrDefault<TResult> Method

Returns the first document of the aggregate result, or the default value if the result set is empty.

Namespace: MongoDB.Driver
Assembly: MongoDB.Driver (in MongoDB.Driver.dll) Version: 2.7.3+Branch.v2.7.x.Sha.2f1f2be13a23b8520cb9c2ee8439c022f9a03efe

Syntax

Copy

public static TResult FirstOrDefault<TResult>(
	this IAggregateFluent<TResult> aggregate,
	CancellationToken cancellationToken = null
)

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

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

Parameters

aggregate: Type: MongoDB.Driver.IAggregateFluent<TResult>
The aggregate.
cancellationToken (Optional): Type: System.Threading.CancellationToken
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 IAggregateFluent<TResult>. 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