# best practice is to use 'try { } catch { }' blocks
try {
    # create client instance
    $client = new MySql();
    # you can specify the text of the query into the Command property
    $client->Command = 'SELECT * FROM users';
    # and execute the query by any method:
    # $client->GetRow();   # return single row
    # $client->GetTable(); # return all rows
    # $client->GetData();  # return array tables
    # for example, get all rows
    $table = $client->GetTable();
    var_dump($table);
    # you can build a query from the input parameters,
    # but you will need to check the type and value of incoming data
    # it is bad practice
    $client->Command = 'DELETE FROM users WHERE id_users = ' . (int) $_GET['id'];
    # it is best to use parameterized queries
    $client->Command = new DBCommand('DELETE FROM users WHERE id_users = @id_users');
    $client->Command->Parameters->Add('@id_users', $_GET['id'], DBParameterType::Integer);
    # or
    # $client->Command->Parameters->Add('@id_users', $_GET['id']);
    # or
    # $client->Command->Parameters->Add('@id_users').SetValue($_GET['id']);
    # it is a safe solution
    # execute the query
    $affectedRows = $client->ExecuteNonQuery();
    echo 'Deleted: ' . $affectedRows . '<br />';
} catch (Exception $ex) {
    echo 'Error: ' . $ex->getMessage();
}