BloodVIRUS

$res->andWhere([
                 'OR', 
                  [
                    'AND', 
                      ['event_seanses' => null],
                      ['<=', 'events.startAt', $startAt], 
                  ],
                  [
                    'AND',
                      ['not', ['event_seanses' => null]],
                      ['<=', 'eventsSeances.startAt', $startAt], 
                  ]
              ]);

public function beforeSave($insert)
    {
         if ($insert){ ваш код }
        return parent::beforeSave($insert); // TODO: Change the autogenerated stub
    }

location /admin/ {
    rewrite (.*) $1?branding=1 break;
    proxy_pass http://site2.com;
}