DbRawSqlQuery<TElement>.FirstAsync Method

 

Asynchronously returns the first element of the query.

Namespace:   System.Data.Entity.Infrastructure
Assembly:  EntityFramework (in EntityFramework.dll)

NameDescription
System_CAPS_pubmethodFirstAsync()

Asynchronously returns the first element of the query.

System_CAPS_pubmethodFirstAsync(CancellationToken)

Asynchronously returns the first element of the query.

System_CAPS_pubmethodFirstAsync(Func<TElement, Boolean>)

Asynchronously returns the first element of the query that satisfies a specified condition.

System_CAPS_pubmethodFirstAsync(Func<TElement, Boolean>, CancellationToken)

Asynchronously returns the first element of the query that satisfies a specified condition.


DbRawSqlQuery<TElement>.FirstAsync Method ()

Asynchronously returns the first element of the query.

public Task<TElement> FirstAsync()

Return Value

Type: System.Threading.Tasks.Task<TElement>

A task that represents the asynchronous operation. The task result contains the first element in the query result.

Exception Condition
InvalidOperationException

The query result is empty.

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>.FirstAsync Method (CancellationToken)

Asynchronously returns the first element of the query.

public Task<TElement> FirstAsync(
	CancellationToken cancellationToken
)

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 first element in the query result.

Exception Condition
InvalidOperationException

The query result is empty.

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>.FirstAsync Method (Func<TElement, Boolean>)

Asynchronously returns the first element of the query that satisfies a specified condition.

public Task<TElement> FirstAsync(
	Func<TElement, bool> predicate
)

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 first element in the query result that satisfies a specified condition.

Exception Condition
ArgumentNullException

predicate is null .

InvalidOperationException

The query result is empty.

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>.FirstAsync Method (Func<TElement, Boolean>, CancellationToken)

Asynchronously returns the first element of the query that satisfies a specified condition.

public Task<TElement> FirstAsync(
	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 first element in the query result that satisfies a specified condition.

Exception Condition
ArgumentNullException

predicate is null .

InvalidOperationException

The query result is empty.

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.