DbRawSqlQuery<TElement>.FirstOrDefaultAsync Method
Definition
Important
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Overloads
| FirstOrDefaultAsync() |
Asynchronously returns the first element of the query, or a default value if the the query result contains no elements. |
| FirstOrDefaultAsync(Func<TElement,Boolean>) |
Asynchronously returns the first element of the query that satisfies a specified condition or a default value if no such element is found. |
| FirstOrDefaultAsync(CancellationToken) |
Asynchronously returns the first element of the query, or a default value if the the query result contains no elements. |
| FirstOrDefaultAsync(Func<TElement,Boolean>, CancellationToken) |
Asynchronously returns the first element of the query that satisfies a specified condition or a default value if no such element is found. |
FirstOrDefaultAsync()
Asynchronously returns the first element of the query, or a default value if the the query result contains no elements.
public System.Threading.Tasks.Task<TElement> FirstOrDefaultAsync ();member this.FirstOrDefaultAsync : unit -> System.Threading.Tasks.Task<'Element>Public Function FirstOrDefaultAsync () As Task(Of TElement)Returns
A task that represents the asynchronous operation.
The task result contains default ( TElement ) if query result is empty;
otherwise, the first element in the query result.
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
FirstOrDefaultAsync(Func<TElement,Boolean>)
Asynchronously returns the first element of the query that satisfies a specified condition or a default value if no such element is found.
public System.Threading.Tasks.Task<TElement> FirstOrDefaultAsync (Func<TElement,bool> predicate);member this.FirstOrDefaultAsync : Func<'Element, bool> -> System.Threading.Tasks.Task<'Element>Public Function FirstOrDefaultAsync (predicate As Func(Of TElement, Boolean)) As Task(Of TElement)Parameters
Returns
A task that represents the asynchronous operation.
The task result contains default ( TElement ) if query result is empty
or if no element passes the test specified by predicate; otherwise, the first element
in the query result that passes the test specified by predicate .
Exceptions
predicate
is
null
.
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
FirstOrDefaultAsync(CancellationToken)
Asynchronously returns the first element of the query, or a default value if the the query result contains no elements.
public System.Threading.Tasks.Task<TElement> FirstOrDefaultAsync (System.Threading.CancellationToken cancellationToken);member this.FirstOrDefaultAsync : 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 default ( TElement ) if query result is empty;
otherwise, the first element in the query result.
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
FirstOrDefaultAsync(Func<TElement,Boolean>, CancellationToken)
Asynchronously returns the first element of the query that satisfies a specified condition or a default value if no such element is found.
public System.Threading.Tasks.Task<TElement> FirstOrDefaultAsync (Func<TElement,bool> predicate, System.Threading.CancellationToken cancellationToken);member this.FirstOrDefaultAsync : 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 default ( TElement ) if query result is empty
or if no element passes the test specified by predicate; otherwise, the first element
in the query result that passes the test specified by predicate .
Exceptions
predicate
is
null
.
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