Added group by statement - fixes MySQL platform incompatibility

.env

@@ -55,8 +55,8 @@ YOUTUBE_API_KEY=
 
 ###> Facebook ###
 # see https://developers.facebook.com/
-FACEBOOK_APP_ID=
-FACEBOOK_APP_SECRET=
+FACEBOOK_APP_ID=12345 # Replace it, it is just to make container compile
+FACEBOOK_APP_SECRET=XYZ # Replace it, it is just to make container compile
 # see https://developers.facebook.com/tools/accesstoken/
 FACEBOOK_ACCESS_TOKEN=
 ###< Facebook#

packages/Training/src/Repository/TrainingRepository.php

@@ -40,6 +40,7 @@ public function fetchRecentlyActive(): array
             ->setParameter(':weekAgo', DateTime::from('- 7 days'))
             ->setParameter(':nextWeek', DateTime::from('+ 7 days'))
             ->groupBy('t.id')
+            ->addGroupBy('tt.startDateTime')
             ->orderBy('tt.startDateTime') // put more recent first
             ->getQuery()
             ->getResult();