MongoQueryableSingleAsyncTSource Method (IQueryableTSource, ExpressionFuncTSource, Boolean, CancellationToken) |
Returns the only element of a sequence that satisfies a specified condition, and throws an exception if more than one such element exists.
Namespace: MongoDB.Driver.LinqAssembly: MongoDB.Driver (in MongoDB.Driver.dll) Version: 2.1.0
Syntax public static Task<TSource> SingleAsync<TSource>(
this IQueryable<TSource> source,
Expression<Func<TSource, bool>> predicate,
CancellationToken cancellationToken = null
)
<ExtensionAttribute>
Public Shared Function SingleAsync(Of TSource) (
source As IQueryable(Of TSource),
predicate As Expression(Of Func(Of TSource, Boolean)),
Optional cancellationToken As CancellationToken = Nothing
) As Task(Of TSource)
[<ExtensionAttribute>]
static member SingleAsync :
source : IQueryable<'TSource> *
predicate : Expression<Func<'TSource, bool>> *
?cancellationToken : CancellationToken
(* Defaults:
let _cancellationToken = defaultArg cancellationToken null
*)
-> Task<'TSource>
Parameters
- source
- Type: System.LinqIQueryableTSource
An IMongoQueryableT to return a single element from. - predicate
- Type: System.Linq.ExpressionsExpressionFuncTSource, Boolean
A function to test an element for a condition. - 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 that satisfies the condition in
predicate.
Usage Note
In Visual Basic and C#, you can call this method as an instance method on any object of type
IQueryableTSource. 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