Mongo aggregation within intervals of time

Question

I have some log data stored in a mongo collection that includes basic information as a request_id and the time it was added to the collection, for example:

{
            


        

Answer 1

Something like this?

pipeline = [
    {"$project":
        {"date": {
            "year": {"$year": "$time"},
            "month": {"$month": "$time"},
            "day": {"$dayOfMonth": "$time"},
            "hour": {"$hour": "$time"},
            "minute": {"$subtract": [
                {"$minute": "$time"},
                {"$mod": [{"$minute": "$time"}, 10]}
            ]}
        }}
    },
    {"$group": {"_id": "$date", "count": {"$sum": 1}}}
]

Example:

> db.foo.insert({"time": new Date(2015,  7, 21, 22, 21)})
> db.foo.insert({"time": new Date(2015,  7, 21, 22, 23)})
> db.foo.insert({"time": new Date(2015,  7, 21, 22, 45)})
> db.foo.insert({"time": new Date(2015,  7, 21, 22, 33)})
> db.foo.aggregate(pipeline)

and output:

{ "_id" : { "year" : 2015, "month" : 8, "day" : 21, "hour" : 20, "minute" : 40 }, "count" : 1 }
{ "_id" : { "year" : 2015, "month" : 8, "day" : 21, "hour" : 20, "minute" : 20 }, "count" : 2 }
{ "_id" : { "year" : 2015, "month" : 8, "day" : 21, "hour" : 20, "minute" : 30 }, "count" : 1 }