mongodb group by sort
db.users.aggregate( [ $sort : age : -1, posts: 1 } } ] ). This operation sorts the documents in the users collection, in descending order according by the age field ... ,The documents are sorted by count in descending order. ... The $sortByCount stage is equivalent to the following $group + $sort sequence: copy. copied.
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 mongodb group by sort 相關參考資料
$group (aggregation) — MongoDB Manual
$group does not order its output documents. ... uses the $first accumulator operator, consider adding an index on the grouped field which matches the sort order. https://docs.mongodb.com $sort (aggregation) — MongoDB Manual
db.users.aggregate( [ $sort : age : -1, posts: 1 } } ] ). This operation sorts the documents in the users collection, in descending order according by the age field ... https://docs.mongodb.com $sortByCount (aggregation) — MongoDB Manual
The documents are sorted by count in descending order. ... The $sortByCount stage is equivalent to the following $group + $sort sequence: copy. copied. https://docs.mongodb.com Mongo aggregation framework, Sort and then group not working
When you $group after a $sort in the pipeline, the previous sort is lost. You'd have to do something like this instead so that the date you want to sort by is ... https://stackoverflow.com MongoDB - group, count and sort example - Mkyong.com
2016年5月3日 — Some MongoDB examples to show you how to perform group by, count and sort query. 1. Test Data. A whois_range collection, containing ... https://mkyong.com Mongodb Aggregation framework group and sort - Stack ...
You can do this: db.collection.aggregate( $sort:"time":1}}, $group: _id: "$sessionId", messages: "$push": message: "$msg", time: "$time"} } } } ). ... https://stackoverflow.com Mongodb group and sort - Stack Overflow
2013年3月13日 — Inspired by this example on mongo's website. GENERATE DUMMY DATA: > db.stack.insert(a:1,b:1,c:1,active:1}) > db.stack.insert(a:1,b:1,c:2 ... https://stackoverflow.com MongoDB group by with sort and limit for each group - Stack ...
2017年9月8日 — My solution is db.collection.aggregate([ $sort:name:-1, score:-1}}, $group:_id:"$name",items:$push:score:"$score"}}}}, ... https://stackoverflow.com Sort and Group in one MongoDB aggregation query - Stack ...
2015年3月26日 — You need to first $group and $sort the result. Since you only want the _id field you will need the $project stage. db.test.aggregate( [ "$group": ... https://stackoverflow.com |