SqlCommand.ExecuteReaderAsync Method

Definition

Namespace:

Microsoft.Data.SqlClient

Assembly:

Microsoft.Data.SqlClient.dll

Package:

Microsoft.Data.SqlClient v5.2.0

Overloads

ExecuteReaderAsync()	An asynchronous version of ExecuteReader() , which sends the CommandText to the Connection and builds a SqlDataReader . Exceptions will be reported via the returned Task object.
ExecuteReaderAsync(CommandBehavior)	An asynchronous version of ExecuteReader(CommandBehavior) , which sends the CommandText to the Connection , and builds a SqlDataReader . Exceptions will be reported via the returned Task object.
ExecuteReaderAsync(CancellationToken)	An asynchronous version of ExecuteReader() , which sends the CommandText to the Connection and builds a SqlDataReader . The cancellation token can be used to request that the operation be abandoned before the command timeout elapses. Exceptions will be reported via the returned Task object.
ExecuteReaderAsync(CommandBehavior, CancellationToken)	An asynchronous version of ExecuteReader(CommandBehavior) , which sends the CommandText to the Connection , and builds a SqlDataReader The cancellation token can be used to request that the operation be abandoned before the command timeout elapses. Exceptions will be reported via the returned Task object.

ExecuteReaderAsync()

An asynchronous version of ExecuteReader() , which sends the CommandText to the Connection and builds a SqlDataReader . Exceptions will be reported via the returned Task object.

public:
 System::Threading::Tasks::Task<Microsoft::Data::SqlClient::SqlDataReader ^> ^ ExecuteReaderAsync();

public System.Threading.Tasks.Task<Microsoft.Data.SqlClient.SqlDataReader> ExecuteReaderAsync ();

override this.ExecuteReaderAsync : unit -> System.Threading.Tasks.Task<Microsoft.Data.SqlClient.SqlDataReader>

Public Function ExecuteReaderAsync () As Task(Of SqlDataReader)

Returns

Task<SqlDataReader>

A task representing the asynchronous operation.

Exceptions

InvalidCastException

A SqlDbType other than Binary or VarBinary was used when Value was set to Stream . For more information about streaming, see SqlClient Streaming Support.

-or-

A SqlDbType other than Char, NChar, NVarChar, VarChar, or Xml was used when Value was set to TextReader .

-or-

A SqlDbType other than Xml was used when Value was set to XmlReader .

ArgumentException

An invalid CommandBehavior value.

InvalidOperationException

Calling ExecuteReaderAsync() more than once for the same instance before task completion.

-or-

The SqlConnection closed or dropped during a streaming operation. For more information about streaming, see SqlClient Streaming Support.

SqlException

SQL Server returned an error while executing the command text.

-or-

A timeout occurred during a streaming operation. For more information about streaming, see SqlClient Streaming Support.

IOException

An error occurred in a Stream , XmlReader or TextReader object during a streaming operation. For more information about streaming, see SqlClient Streaming Support.

ObjectDisposedException

The Stream , XmlReader or TextReader object was closed during a streaming operation. For more information about streaming, see SqlClient Streaming Support.

Remarks

For more information about asynchronous programming in the .NET Framework Data Provider for SQL Server, see Asynchronous Programming.

Note

For long running queries on the server, consider using ExecuteReader due to a known issue with canceling queries via a cancellation token. Also, consider canceling execution using the Cancel method.

ExecuteReaderAsync(CommandBehavior)

An asynchronous version of ExecuteReader(CommandBehavior) , which sends the CommandText to the Connection , and builds a SqlDataReader . Exceptions will be reported via the returned Task object.

public:
 System::Threading::Tasks::Task<Microsoft::Data::SqlClient::SqlDataReader ^> ^ ExecuteReaderAsync(System::Data::CommandBehavior behavior);

public System.Threading.Tasks.Task<Microsoft.Data.SqlClient.SqlDataReader> ExecuteReaderAsync (System.Data.CommandBehavior behavior);

override this.ExecuteReaderAsync : System.Data.CommandBehavior -> System.Threading.Tasks.Task<Microsoft.Data.SqlClient.SqlDataReader>

Public Function ExecuteReaderAsync (behavior As CommandBehavior) As Task(Of SqlDataReader)

Parameters

behavior

CommandBehavior

Options for statement execution and data retrieval. When is set to Default , ReadAsync(CancellationToken) reads the entire row before returning a complete Task.

Returns

Task<SqlDataReader>

A task representing the asynchronous operation.

Exceptions

InvalidCastException

A SqlDbType other than Binary or VarBinary was used when Value was set to Stream . For more information about streaming, see SqlClient Streaming Support.

-or-

A SqlDbType other than Char, NChar, NVarChar, VarChar, or Xml was used when Value was set to TextReader .

-or-

A SqlDbType other than Xml was used when Value was set to XmlReader .

ArgumentException

An invalid CommandBehavior value.

InvalidOperationException

Calling ExecuteReaderAsync(CommandBehavior) more than once for the same instance before task completion.

-or- SqlConnection closed or dropped during a streaming operation. For more information about streaming, see SqlClient Streaming Support.

SqlException

SQL Server returned an error while executing the command text.

-or-

A timeout occurred during a streaming operation. For more information about streaming, see SqlClient Streaming Support.

IOException

An error occurred in a Stream , XmlReader or TextReader object during a streaming operation. For more information about streaming, see SqlClient Streaming Support.

ObjectDisposedException

The Stream , XmlReader or TextReader object was closed during a streaming operation. For more information about streaming, see SqlClient Streaming Support.

Remarks

For more information about asynchronous programming in the .NET Framework Data Provider for SQL Server, see Asynchronous Programming.

ExecuteReaderAsync(CancellationToken)

An asynchronous version of ExecuteReader() , which sends the CommandText to the Connection and builds a SqlDataReader .

The cancellation token can be used to request that the operation be abandoned before the command timeout elapses. Exceptions will be reported via the returned Task object.

public:
 System::Threading::Tasks::Task<Microsoft::Data::SqlClient::SqlDataReader ^> ^ ExecuteReaderAsync(System::Threading::CancellationToken cancellationToken);

public System.Threading.Tasks.Task<Microsoft.Data.SqlClient.SqlDataReader> ExecuteReaderAsync (System.Threading.CancellationToken cancellationToken);

override this.ExecuteReaderAsync : System.Threading.CancellationToken -> System.Threading.Tasks.Task<Microsoft.Data.SqlClient.SqlDataReader>

Public Function ExecuteReaderAsync (cancellationToken As CancellationToken) As Task(Of SqlDataReader)

Parameters

cancellationToken

CancellationToken

The cancellation instruction.

Returns

Task<SqlDataReader>

A task representing the asynchronous operation.

Exceptions

InvalidCastException

A SqlDbType other than Binary or VarBinary was used when Value was set to Stream . For more information about streaming, see SqlClient Streaming Support.

-or-

A SqlDbType other than Char, NChar, NVarChar, VarChar, or Xml was used when Value was set to TextReader .

-or-

A SqlDbType other than Xml was used when Value was set to XmlReader .

ArgumentException

An invalid CommandBehavior value.

InvalidOperationException

Calling ExecuteReaderAsync(CommandBehavior, CancellationToken) more than once for the same instance before task completion.

-or-

The SqlConnection closed or dropped during a streaming operation. For more information about streaming, see SqlClient Streaming Support.

SqlException

SQL Server returned an error while executing the command text.

-or-

A timeout occurred during a streaming operation. For more information about streaming, see SqlClient Streaming Support.

IOException

An error occurred in a Stream , XmlReader or TextReader object during a streaming operation. For more information about streaming, see SqlClient Streaming Support.

ObjectDisposedException

The Stream , XmlReader or TextReader object was closed during a streaming operation. For more information about streaming, see SqlClient Streaming Support.

Remarks

For more information about asynchronous programming in the .NET Framework Data Provider for SQL Server, see Asynchronous Programming.

ExecuteReaderAsync(CommandBehavior, CancellationToken)

An asynchronous version of ExecuteReader(CommandBehavior) , which sends the CommandText to the Connection , and builds a SqlDataReader The cancellation token can be used to request that the operation be abandoned before the command timeout elapses. Exceptions will be reported via the returned Task object.

public:
 System::Threading::Tasks::Task<Microsoft::Data::SqlClient::SqlDataReader ^> ^ ExecuteReaderAsync(System::Data::CommandBehavior behavior, System::Threading::CancellationToken cancellationToken);

public System.Threading.Tasks.Task<Microsoft.Data.SqlClient.SqlDataReader> ExecuteReaderAsync (System.Data.CommandBehavior behavior, System.Threading.CancellationToken cancellationToken);

override this.ExecuteReaderAsync : System.Data.CommandBehavior * System.Threading.CancellationToken -> System.Threading.Tasks.Task<Microsoft.Data.SqlClient.SqlDataReader>

Public Function ExecuteReaderAsync (behavior As CommandBehavior, cancellationToken As CancellationToken) As Task(Of SqlDataReader)

Parameters

behavior

CommandBehavior

Options for statement execution and data retrieval. When is set to Default , ReadAsync(CancellationToken) reads the entire row before returning a complete Task.

cancellationToken

CancellationToken

The cancellation instruction.

Returns

Task<SqlDataReader>

A task representing the asynchronous operation.

Exceptions

InvalidCastException

A SqlDbType other than Binary or VarBinary was used when Value was set to Stream . For more information about streaming, see SqlClient Streaming Support.

-or-

A SqlDbType other than Char, NChar, NVarChar, VarChar, or Xml was used when Value was set to TextReader .

-or-

A SqlDbType other than Xml was used when Value was set to XmlReader .

ArgumentException

An invalid CommandBehavior value.

InvalidOperationException

Calling ExecuteReaderAsync(CommandBehavior, CancellationToken) more than once for the same instance before task completion.

-or-

The SqlConnection closed or dropped during a streaming operation. For more information about streaming, see SqlClient Streaming Support.

SqlException

SQL Server returned an error while executing the command text.

-or-

A timeout occurred during a streaming operation. For more information about streaming, see SqlClient Streaming Support.

IOException

An error occurred in a Stream , XmlReader or TextReader object during a streaming operation. For more information about streaming, see SqlClient Streaming Support.

ObjectDisposedException

The Stream , XmlReader or TextReader object was closed during a streaming operation. For more information about streaming, see SqlClient Streaming Support.

Remarks

For more information about asynchronous programming in the .NET Framework Data Provider for SQL Server, see Asynchronous Programming.