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IAsyncCursorSourceExtensions.SingleOrDefaultAsync<TDocument> Method

Returns the only document of a cursor returned by a cursor source, 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: 2.15.0+f503bf610759c13f78cff9a3c01e91453185d2ed
Syntax
public static Task<TDocument> SingleOrDefaultAsync<TDocument>(
	this IAsyncCursorSource<TDocument> source,
	CancellationToken cancellationToken = default
)

Parameters

source
Type: MongoDB.Driver.IAsyncCursorSource<TDocument>
The source.
cancellationToken (Optional)
Type: System.Threading.CancellationToken
The cancellation token.

Type Parameters

TDocument
The type of the document.

Return Value

Type: Task<TDocument>
A Task whose result is 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 IAsyncCursorSource<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).
See Also