Επεξεργασία

Κοινή χρήση μέσω


SqlCommand.ExecuteReaderAsync Method

Definition

Initiates the asynchronous execution of the Transact-SQL statement or stored procedure that is described by this SqlCommand.

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.

Remarks

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

ExecuteReaderAsync()

Source:
System.Data.SqlClient.notsupported.cs

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<System::Data::SqlClient::SqlDataReader ^> ^ ExecuteReaderAsync();
public System.Threading.Tasks.Task<System.Data.SqlClient.SqlDataReader> ExecuteReaderAsync ();
override this.ExecuteReaderAsync : unit -> System.Threading.Tasks.Task<System.Data.SqlClient.SqlDataReader>
Public Function ExecuteReaderAsync () As Task(Of SqlDataReader)

Returns

A task representing the asynchronous operation.

Exceptions

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.

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.

-or-

Context Connection=true is specified in the connection string.

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.

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

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.

This method stores in the task it returns all non-usage exceptions that the method's synchronous counterpart can throw. If an exception is stored into the returned task, that exception will be thrown when the task is awaited. Usage exceptions, such as ArgumentException, are still thrown synchronously. For the stored exceptions, see the exceptions thrown by ExecuteReader().

See also

Applies to

ExecuteReaderAsync(CommandBehavior)

Source:
System.Data.SqlClient.notsupported.cs

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<System::Data::SqlClient::SqlDataReader ^> ^ ExecuteReaderAsync(System::Data::CommandBehavior behavior);
public System.Threading.Tasks.Task<System.Data.SqlClient.SqlDataReader> ExecuteReaderAsync (System.Data.CommandBehavior behavior);
override this.ExecuteReaderAsync : System.Data.CommandBehavior -> System.Threading.Tasks.Task<System.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

A task representing the asynchronous operation.

Exceptions

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.

Calling ExecuteReaderAsync(CommandBehavior) 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.

-or-

Context Connection=true is specified in the connection string.

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.

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

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.

This method stores in the task it returns all non-usage exceptions that the method's synchronous counterpart can throw. If an exception is stored into the returned task, that exception will be thrown when the task is awaited. Usage exceptions, such as ArgumentException, are still thrown synchronously. For the stored exceptions, see the exceptions thrown by ExecuteReader(CommandBehavior).

See also

Applies to

ExecuteReaderAsync(CancellationToken)

Source:
System.Data.SqlClient.notsupported.cs

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<System::Data::SqlClient::SqlDataReader ^> ^ ExecuteReaderAsync(System::Threading::CancellationToken cancellationToken);
public System.Threading.Tasks.Task<System.Data.SqlClient.SqlDataReader> ExecuteReaderAsync (System.Threading.CancellationToken cancellationToken);
override this.ExecuteReaderAsync : System.Threading.CancellationToken -> System.Threading.Tasks.Task<System.Data.SqlClient.SqlDataReader>
Public Function ExecuteReaderAsync (cancellationToken As CancellationToken) As Task(Of SqlDataReader)

Parameters

cancellationToken
CancellationToken

The cancellation instruction.

Returns

A task representing the asynchronous operation.

Exceptions

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.

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.

-or-

Context Connection=true is specified in the connection string.

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.

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

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

The cancellation token was canceled. This exception is stored into the returned task.

Remarks

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

This method stores in the task it returns all non-usage exceptions that the method's synchronous counterpart can throw. If an exception is stored into the returned task, that exception will be thrown when the task is awaited. Usage exceptions, such as ArgumentException, are still thrown synchronously. For the stored exceptions, see the exceptions thrown by ExecuteReader().

See also

Applies to

ExecuteReaderAsync(CommandBehavior, CancellationToken)

Source:
System.Data.SqlClient.notsupported.cs

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

A task representing the asynchronous operation.

Exceptions

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.

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.

-or-

Context Connection=true is specified in the connection string.

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.

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

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

The cancellation token was canceled. This exception is stored into the returned task.

Remarks

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

This method stores in the task it returns all non-usage exceptions that the method's synchronous counterpart can throw. If an exception is stored into the returned task, that exception will be thrown when the task is awaited. Usage exceptions, such as ArgumentException, are still thrown synchronously. For the stored exceptions, see the exceptions thrown by ExecuteReader(CommandBehavior).

See also

Applies to