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SqlConnectionStringBuilder.AsynchronousProcessing Property

Note: This property is new in the .NET Framework version 2.0.

Gets or sets a Boolean value that indicates whether asynchronous processing is allowed by the connection created by using this connection string.

Namespace: System.Data.SqlClient
Assembly: System.Data (in

public bool AsynchronousProcessing { get; set; 
/** @property */
public boolean get_AsynchronousProcessing ()

/** @property */
public void set_AsynchronousProcessing (boolean value)

public function get AsynchronousProcessing () : boolean

public function set AsynchronousProcessing (value : boolean)

Property Value

The value of the AsynchronousProcessing property, or false if no value has been supplied.

This property corresponds to the "Asynchronous Processing" and "async" keys within the connection string. In order to take advantage of the asynchronous processing provided by the SqlCommand object, this key/value pair must be included within the connection string of the associated SqlConnection object.

The following example retrieves a connection string and verifies that the connection string is configured to allow for asynchronous processing. (In this case, the string comes from a procedure within the application, but in a production application, the connection string might come from a configuration file, or some other source.) Then, the example performs an asynchronous operation, updating values within a sample database on a background thread.

using System.Data.SqlClient;
using System.Threading;

class Program
    static void Main()
        // Create a SqlConnectionStringBuilder instance, 
        // and ensure that it is set up for asynchronous processing.
        SqlConnectionStringBuilder builder =
            new SqlConnectionStringBuilder(GetConnectionString());
        // Asynchronous method calls won't work unless you
        // have added this option, or have added
        // the clause "Asynchronous Processing=true"
        // to the connection string.
        builder.AsynchronousProcessing = true;

        string commandText =
            "UPDATE Production.Product SET ReorderPoint = ReorderPoint + 1 " +
            "WHERE ReorderPoint IS NOT Null;" +
            "WAITFOR DELAY '0:0:3';" +
            "UPDATE Production.Product SET ReorderPoint = ReorderPoint - 1 " +
            "WHERE ReorderPoint IS NOT Null";
        RunCommandAsynchronously(commandText, builder.ConnectionString);

        Console.WriteLine("Press any key to finish.");

    private static string GetConnectionString()
        // To avoid storing the connection string in your code,
        // you can retrieve it from a configuration file. 
        return "Data Source=(local);Integrated Security=SSPI;" +
            "Initial Catalog=AdventureWorks";

    private static void RunCommandAsynchronously(string commandText, 
        string connectionString)
        // Given command text and connection string, asynchronously execute
        // the specified command against the connection. For this example,
        // the code displays an indicator as it's working, verifying the 
        // asynchronous behavior. 
        using (SqlConnection connection = new SqlConnection(connectionString))
                int count = 0;
                SqlCommand command = new SqlCommand(commandText, connection);
                IAsyncResult result = command.BeginExecuteNonQuery();
                while (!result.IsCompleted)
                    Console.WriteLine("Waiting {0.", count);
                    // Wait for 1/10 second, so the counter
                    // doesn't consume all available resources 
                    // on the main thread.
                    count += 1;
                Console.WriteLine("Command complete. Affected {0 rows.",

            catch (SqlException ex)
                    "Error {0: System.Data.SqlClient.SqlConnectionStringBuilder", 
                    ex.Number, ex.Message);
            catch (InvalidOperationException ex)
                Console.WriteLine("Error: {0", ex.Message);
            catch (Exception ex)
                // You might want to pass these errors
                // back out to the caller.
                Console.WriteLine("Error: {0", ex.Message);

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0