/**
* @param \App\Repository\Entity\Station $station
* @param \App\Repository\Entity\Component $component
* @param \DateTime $start
* @param \DateTime|null $to
*
* @return float|null
*/
public function getStationAverageForTimeAndComponent(Station $station, Component $component, \DateTime $start, \DateTime $to = null)
{
$query = $this->queryBuilder->from(self::$tableName);
$query->where('station_id', $station->getId());
$query->where('component_id', $component->getId());
$query->where('measure_timestamp >= "' . $start->format("Y-m-d H:i:s") . '"');
if (isset($to)) {
$query->where('measure_timestamp <= "' . $to->format("Y-m-d H:i:s") . '"');
}
$query->select('AVG(value) AS average');
$result = $query->fetch('average');
return !empty($result) ? floatval($result) : null;
}