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MongoQueryableSingleOrDefaultAsyncTSource Method (IMongoQueryableTSource, CancellationToken)

Returns the only element of a sequence, or a default value if the sequence is empty; this method throws an exception if there is more than one element in the sequence.

Namespace:  MongoDB.Driver.Linq
Assembly:  MongoDB.Driver (in MongoDB.Driver.dll) Version: 2.20.0+ee01960089f28ea1b501690df5fc9f6318a70242
Syntax
public static Task<TSource> SingleOrDefaultAsync<TSource>(
	this IMongoQueryable<TSource> source,
	CancellationToken cancellationToken = null
)

Parameters

source
Type: MongoDB.Driver.LinqIMongoQueryableTSource
An IMongoQueryableT to return the single element of.
cancellationToken (Optional)
Type: System.ThreadingCancellationToken
The cancellation token.

Type Parameters

TSource
The type of the elements of source.

Return Value

Type: TaskTSource
The single element of the input sequence, or default(TSource) if the sequence contains no elements.

Usage Note

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