javascript Mongo Group Aggregate

Posted 2021-05-04

//GROUP BY WORKSHOP ID
db.getCollection('enrolments').aggregate([{
   $group:
   {
       _id: {workshopId: "$workshopId"},
       contacts: { $push:  {contactId: '$contactId'} }
   }
}])

GROUP FIRST BY WEEKDAY AND WORKSHOP THEN BY WEEKDAY
db.getCollection('enrolments').aggregate([
   { $unwind: '$attendances' },
   {
       $group:
       {
           _id: {weekDay: "$attendances.weekDay", workshopId:"$workshopId"},
           contacts: { $push:  {contactId: '$contactId', day: "$attendances.day", status:'$attendances.status'} }
       }
   },
   {
       $group:
       {
           _id: {weekDay: "$_id.weekDay"},
           workshops: { $push:  {workshopId:'$_id.workshopId', contacts: '$contacts'} }
       }
   }
])