DbRawSqlQuery<TElement>.SingleAsync Method
Definition
Important
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Overloads
| SingleAsync() |
Asynchronously returns the only element of the query, and throws an exception if there is not exactly one element in the sequence. |
| SingleAsync(Func<TElement,Boolean>) |
Asynchronously returns the only element of the query that satisfies a specified condition, and throws an exception if more than one such element exists. |
| SingleAsync(CancellationToken) |
Asynchronously returns the only element of the query, and throws an exception if there is not exactly one element in the sequence. |
| SingleAsync(Func<TElement,Boolean>, CancellationToken) |
Asynchronously returns the only element of the query that satisfies a specified condition, and throws an exception if more than one such element exists. |
SingleAsync()
Asynchronously returns the only element of the query, and throws an exception if there is not exactly one element in the sequence.
public System.Threading.Tasks.Task<TElement> SingleAsync ();member this.SingleAsync : unit -> System.Threading.Tasks.Task<'Element>Public Function SingleAsync () As Task(Of TElement)Returns
A task that represents the asynchronous operation. The task result contains the single element of the query result.
Exceptions
The query result is empty.
Remarks
Multiple active operations on the same context instance are not supported. Use 'await' to ensure that any asynchronous operations have completed before calling another method on this context.
Applies to
SingleAsync(Func<TElement,Boolean>)
Asynchronously returns the only element of the query that satisfies a specified condition, and throws an exception if more than one such element exists.
public System.Threading.Tasks.Task<TElement> SingleAsync (Func<TElement,bool> predicate);member this.SingleAsync : Func<'Element, bool> -> System.Threading.Tasks.Task<'Element>Public Function SingleAsync (predicate As Func(Of TElement, Boolean)) As Task(Of TElement)Parameters
Returns
A task that represents the asynchronous operation.
The task result contains the single element of the query result that satisfies the condition in
predicate.
Exceptions
predicate
is
null
.
More than one element satisfies the condition in
predicate
.
Remarks
Multiple active operations on the same context instance are not supported. Use 'await' to ensure that any asynchronous operations have completed before calling another method on this context.
Applies to
SingleAsync(CancellationToken)
Asynchronously returns the only element of the query, and throws an exception if there is not exactly one element in the sequence.
public System.Threading.Tasks.Task<TElement> SingleAsync (System.Threading.CancellationToken cancellationToken);member this.SingleAsync : System.Threading.CancellationToken -> System.Threading.Tasks.Task<'Element>Parameters
- cancellationToken
- CancellationToken
A CancellationToken to observe while waiting for the task to complete.
Returns
A task that represents the asynchronous operation. The task result contains the single element of the query result.
Exceptions
The query result is empty.
Remarks
Multiple active operations on the same context instance are not supported. Use 'await' to ensure that any asynchronous operations have completed before calling another method on this context.
Applies to
SingleAsync(Func<TElement,Boolean>, CancellationToken)
Asynchronously returns the only element of the query that satisfies a specified condition, and throws an exception if more than one such element exists.
public System.Threading.Tasks.Task<TElement> SingleAsync (Func<TElement,bool> predicate, System.Threading.CancellationToken cancellationToken);member this.SingleAsync : Func<'Element, bool> * System.Threading.CancellationToken -> System.Threading.Tasks.Task<'Element>Parameters
- cancellationToken
- CancellationToken
A CancellationToken to observe while waiting for the task to complete.
Returns
A task that represents the asynchronous operation.
The task result contains the single element of the query result that satisfies the condition in
predicate.
Exceptions
predicate
is
null
.
More than one element satisfies the condition in
predicate
.
Remarks
Multiple active operations on the same context instance are not supported. Use 'await' to ensure that any asynchronous operations have completed before calling another method on this context.
Applies to
Entity Framework