EndExecuteNonQuery Method (DB2Command)

In This Topic

Ends an asynchronous invocation of the ExecuteNonQuery method.

Syntax

Visual Basic
C#

'Declaration
 
Public Shadows Function EndExecuteNonQuery( _
   ByVal result As IAsyncResult _
) As Integer

public new int EndExecuteNonQuery( 
   IAsyncResult result
)

Parameters

result: The System.IAsyncResult returned from BeginExecuteNonQuery.

Return Value

For UPDATE, INSERT, and DELETE statements, the return value is the number of rows affected by the command. For all other types of statements, the return value is -1.

Remarks

The function ends an asynchronous execution of a query that is started with BeginExecuteNonQuery. A pair of asynchronous functions (BeginExecuteNonQuery and EndExecuteNonQuery) can be used instead of the synchronous function ExecuteNonQuery to gain more performance and flexibility in your application.

Refer to "Asynchronous Query Execution" article for detailed information.

Example

In the example below an easiest way of executing an asynchronous operation is shown. First, all components are set up and a connection is opened. Second, a query execution is started. The operation state (done or in progress) is checked and a report is written to the console. At last query result is rendered.

csharp

static void Async_Exec(DbConnectionBase myConnection)
{
  DbCommandBase myCommand = (DbCommandBase)myConnection.CreateCommand();
  myCommand.CommandText = "UPDATE Dept SET DName='New Department' WHERE DeptNo=10";
  Console.WriteLine("Starting asynchronous query execution...");
  myConnection.Open();
  IAsyncResult cres = myCommand.BeginExecuteNonQuery(null, null);
  if (cres.IsCompleted)
    Console.WriteLine("Completed.");
  else
    Console.WriteLine("Have to wait for operation to complete...");
  try
  {
    int RowsAffected = myCommand.EndExecuteNonQuery(cres);
    Console.WriteLine("Done. Rows affected: " + RowsAffected.ToString());
  }
  catch (Exception e)
  {
    Console.WriteLine("An exception has occurred: " + e.Message);
  }
  finally
  {
    myConnection.Close();
  }
}

Visual Basic

Public Sub Async_Exec(ByVal myConnection As DbConnectionBase)
  Dim myCommand As DbCommandBase = myConnection.CreateCommand()
  myCommand.CommandText = "UPDATE Dept SET DName='New Department' WHERE DeptNo=20"
  Console.WriteLine("Starting asynchronous query execution...")
  myConnection.Open()
  Dim cres As IAsyncResult = myCommand.BeginExecuteNonQuery(Nothing, Nothing)
  If cres.IsCompleted Then
    Console.WriteLine("Completed.")
  Else
    Console.WriteLine("Have to wait for operation to complete...")
  End If
  Try
    Dim RowsAffected As Integer = myCommand.EndExecuteNonQuery(cres)
    Console.WriteLine(String.Concat("Rows affected: ", RowsAffected.ToString()))
  Catch e As Exception
    Console.WriteLine(String.Concat("An exception has occurred: ", e.Message))
  Finally
    myConnection.Close()
  End Try
End Sub

Reference

DB2Command Class
DB2Command Members

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