IAsyncCursorExtensions.SingleOrDefault(TDocument) Method

IAsyncCursorExtensionsSingleOrDefaultTDocument Method

Returns the only document of a cursor, or a default value if the cursor contains no documents. This method throws an exception if the cursor contains more than one document.

Namespace: MongoDB.Driver
Assembly: MongoDB.Driver.Core (in MongoDB.Driver.Core.dll) Version: 2.4.1

Syntax

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public static TDocument SingleOrDefault<TDocument>(
	this IAsyncCursor<TDocument> cursor,
	CancellationToken cancellationToken = null
)

<ExtensionAttribute>
Public Shared Function SingleOrDefault(Of TDocument) ( 
	cursor As IAsyncCursor(Of TDocument),
	Optional cancellationToken As CancellationToken = Nothing
) As TDocument

[<ExtensionAttribute>]
static member SingleOrDefault : 
        cursor : IAsyncCursor<'TDocument> * 
        ?cancellationToken : CancellationToken 
(* Defaults:
        let _cancellationToken = defaultArg cancellationToken null
*)
-> 'TDocument

Parameters

cursor: Type: MongoDB.DriverIAsyncCursorTDocument
The cursor.
cancellationToken (Optional): Type: System.ThreadingCancellationToken
The cancellation token.

Type Parameters

TDocument: The type of the document.

Return Value

Type: TDocument
The only document of a cursor, or a default value if the cursor contains no documents.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IAsyncCursorTDocument. 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

IAsyncCursorExtensions Class

MongoDB.Driver Namespace