Count events and insert string literal during aggregation

Question

I have large collection of documents which represent some kind of events. Collection contains events for different userId.

{
    \"_id\" : ObjectId(\"57fd7d00e4b         


        

Answer 1

Check the following query

db.sandbox.aggregate([{ 
    $group: {
        _id: {
            userId: "$userId", 
            date: {
                $dateToString: { format: "%Y-%m-%d", date: "$timestamp" }} 
            }, 
        send_message: { 
            $sum: { 
                $cond: { if: { $eq: ["$event_type", "send_message"] }, then: 1, else: 0 } } 
            },
        clicked_cancel: { 
            $sum: { 
                $cond: { if: { $eq: ["$event_type", "clicked_cancel"] }, then: 1, else: 0 } 
            } 
        },
        clicked_ok: { 
            $sum: { 
                $cond: { if: { $eq: ["$event_type", "clicked_ok"] }, then: 1, else: 0 } 
            } 
        }
    }
}])