Database
[{"staffId":12345,"category":"trend","page_route":"http://example.com/rer","expireAt":ISODate("2020-08-13T11:08:45.196Z"),"createdAt":ISODate("2020-08-13T11:08:45.199Z"),"updatedAt":ISODate("2020-08-13T11:08:45.199Z"),"__v":0},{"staffId":12346,"category":"incident","page_route":"http://example.com/rergfhfhf","expireAt":ISODate("2020-08-14T11:08:45.196Z"),"createdAt":ISODate("2020-08-08T11:08:45.199Z"),"updatedAt":ISODate("2020-08-12T11:08:45.199Z"),"__v":0},{"staffId":12347,"category":"trend","page_route":"http://example.com/rerrwe","expireAt":ISODate("2020-08-13T11:08:45.196Z"),"createdAt":ISODate("2020-08-13T11:08:45.199Z"),"updatedAt":ISODate("2020-08-13T11:08:45.199Z"),"__v":0},{"staffId":12348,"category":"trend","page_route":"http://example.com/rerrwe","expireAt":ISODate("2020-08-12T11:08:45.196Z"),"createdAt":ISODate("2020-08-08T11:08:45.199Z"),"updatedAt":ISODate("2020-08-12T11:08:45.199Z"),"__v":0}]
Query
db.collection.aggregate([{$group:{_id:{year:{$year:"$createdAt"},week:{$week:"$createdAt"}},createdAt:{$first:"$createdAt"},count:{$sum:1}}}])