private function _getNextValue($sequence = 'admin')
{
$transaction = $this->db->beginTransaction();
$table = $this->db->getConfig('sequence.table');
$name = $this->db->getConfig('sequence.name');
$field = $this->db->getConfig('sequence.value');
$sql = new \Maestro\Database\MSQL($field, $table, "({$name} = '{$sequence}')");
$sql->setForUpdate(true);
$result = $this->db->query($sql);
$value = \Manager::getOptions('fetchStyle') == \FETCH_NUM ? $result[0][0] : $result[0][$field];
$nextValue = $value + 1;
$this->db->execute($sql->update($nextValue), $nextValue);
$transaction->commit();
return $value;
}