public function findByPk($keys)
{
if ($keys === null) {
return null;
}
list($where, $parameters) = $this->getPrimaryKeyCondition((array) $keys);
$command = $this->getBuilder()->createFindCommand($where, $parameters);
$this->onCreateCommand($command, new TSqlCriteria($where, $parameters));
return $this->onExecuteCommand($command, $command->queryRow());
}