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: 2.19.1+3a2a09dd959482f665ffbb5df2557ec541597af4
Syntax public static Task<TSource> SingleOrDefaultAsync<TSource>(
this IMongoQueryable<TSource> source,
CancellationToken cancellationToken = default
)
<ExtensionAttribute>
Public Shared Function SingleOrDefaultAsync(Of TSource) (
source As IMongoQueryable(Of TSource),
Optional cancellationToken As CancellationToken = Nothing
) As Task(Of TSource)
[<ExtensionAttribute>]
static member SingleOrDefaultAsync :
source : IMongoQueryable<'TSource> *
?cancellationToken : CancellationToken
(* Defaults:
let _cancellationToken = defaultArg cancellationToken new CancellationToken()
*)
-> Task<'TSource>
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