DbRawSqlQuery<TElement>::SingleOrDefaultAsync Method
Asynchronously 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.
Assembly: EntityFramework (in EntityFramework.dll)
| Name | Description | |
|---|---|---|
![]() | SingleOrDefaultAsync() | Asynchronously 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. |
![]() | SingleOrDefaultAsync(CancellationToken) | Asynchronously 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. |
![]() | SingleOrDefaultAsync(Func<TElement, Boolean>^) | Asynchronously returns the only element of the query that satisfies a specified condition or a default value if no such element exists; this method throws an exception if more than one element satisfies the condition. |
![]() | SingleOrDefaultAsync(Func<TElement, Boolean>^, CancellationToken) | Asynchronously returns the only element of the query that satisfies a specified condition or a default value if no such element exists; this method throws an exception if more than one element satisfies the condition. |
DbRawSqlQuery<TElement>::SingleOrDefaultAsync Method ()
Asynchronously 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.
| Exception | Condition |
|---|---|
| InvalidOperationException | The query result has more than one element. |
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.
DbRawSqlQuery<TElement>::SingleOrDefaultAsync Method (CancellationToken)
Asynchronously 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.
Parameters
- cancellationToken
-
Type:
System.Threading::CancellationToken
A CancellationToken to observe while waiting for the task to complete.
Return Value
Type: System.Threading.Tasks::Task<TElement>^A task that represents the asynchronous operation. The task result contains the single element of the query result, or default ( TElement ) if the sequence contains no elements.
| Exception | Condition |
|---|---|
| InvalidOperationException | The query result has more than one element. |
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.
DbRawSqlQuery<TElement>::SingleOrDefaultAsync Method (Func<TElement, Boolean>^)
Asynchronously returns the only element of the query that satisfies a specified condition or a default value if no such element exists; this method throws an exception if more than one element satisfies the condition.
Parameters
- predicate
-
Type:
System::Func<TElement, Boolean>^
A function to test each element for a condition.
Return Value
Type: System.Threading.Tasks::Task<TElement>^A task that represents the asynchronous operation. The task result contains the single element of the query result that satisfies the condition in predicate, or default ( TElement ) if no such element is found.
| Exception | Condition |
|---|---|
| ArgumentNullException | predicate is null . |
| InvalidOperationException | More than one element satisfies the condition in predicate . |
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.
DbRawSqlQuery<TElement>::SingleOrDefaultAsync Method (Func<TElement, Boolean>^, CancellationToken)
Asynchronously returns the only element of the query that satisfies a specified condition or a default value if no such element exists; this method throws an exception if more than one element satisfies the condition.
public: Task<TElement>^ SingleOrDefaultAsync( Func<TElement, bool>^ predicate, CancellationToken cancellationToken )
Parameters
- predicate
-
Type:
System::Func<TElement, Boolean>^
A function to test each element for a condition.
- cancellationToken
-
Type:
System.Threading::CancellationToken
A CancellationToken to observe while waiting for the task to complete.
Return Value
Type: System.Threading.Tasks::Task<TElement>^A task that represents the asynchronous operation. The task result contains the single element of the query result that satisfies the condition in predicate, or default ( TElement ) if no such element is found.
| Exception | Condition |
|---|---|
| ArgumentNullException | predicate is null . |
| InvalidOperationException | More than one element satisfies the condition in predicate . |
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.
