IAsyncCursorExtensions.SingleOrDefault<TDocument> 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: 2.21.0+5a9c3311e158910b88195f290e6d4b1b2715d2b2

Syntax

Copy

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.Driver.IAsyncCursor<TDocument>
The cursor.
cancellationToken (Optional): Type: System.Threading.CancellationToken
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 IAsyncCursor<TDocument>. 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