SAConnection conn = new SAConnection("DSN=SQL Anywhere 12 Demo");
conn.Open();
SACommand cmd = new SACommand(
    "UPDATE Departments"
        + " SET DepartmentName = 'Engineering'"
        + " WHERE DepartmentID=100",
    conn );
IAsyncResult res = cmd.BeginExecuteNonQuery();
// perform other work
// this will block until the command completes
int rowCount reader = cmd.EndExecuteNonQuery( res );

SAConnection conn = new SAConnection("DSN=SQL Anywhere 12 Demo");
conn.Open();
SACommand cmd = new SACommand(
    "UPDATE Departments"
        + " SET DepartmentName = 'Engineering'"
        + " WHERE DepartmentID=100",
    conn );
IAsyncResult res = cmd.BeginExecuteNonQuery();
while( !res.IsCompleted ) {
    // do other work
}
// this will not block because the command is finished
int rowCount = cmd.EndExecuteNonQuery( res );

SAConnection conn = new SAConnection("DSN=SQL Anywhere 12 Demo");
conn.Open();
SACommand cmd = new SACommand(
    "UPDATE Departments"
        + " SET DepartmentName = 'Engineering'"
        + " WHERE DepartmentID=100",
    conn );
IAsyncResult res = cmd.BeginExecuteNonQuery();
// perform other work
WaitHandle wh = res.AsyncWaitHandle;
wh.WaitOne();
// this will not block because the command is finished
int rowCount = cmd.EndExecuteNonQuery( res );

private void callbackFunction( IAsyncResult ar ) {
    SACommand cmd = (SACommand) ar.AsyncState;
    // this won't block since the command has completed
    int rowCount = cmd.EndExecuteNonQuery();
}

// elsewhere in the code
private void DoStuff() {
    SAConnection conn = new SAConnection("DSN=SQL Anywhere 12 Demo");
    conn.Open();
    SACommand cmd = new SACommand(
        "UPDATE Departments"
            + " SET DepartmentName = 'Engineering'"
            + " WHERE DepartmentID=100",
        conn );
    IAsyncResult res = cmd.BeginExecuteNonQuery( callbackFunction, cmd );
    // perform other work.  The callback function will be
    // called when the command completes
}