node.js - Mongoose group aggregation don't return the rest of fields -

node.js - Mongoose group aggregation don't return the rest of fields -

hello have next code working now:

app.get('/api/checkav/:checkin/:checkout', function(req, res) { var checkin = req.params.checkin, checkout = req.params.checkout, roomtype = req.params.roomtype, startdate = moment(checkin), enddate = moment(checkout), nights = enddate.diff(startdate, 'days'); model.av.aggregate([ {$match: {dateofday: {$gte: new date(checkin), $lt:new date(checkout)} }}, {$group: { _id: '$roomid', total: {$sum: '$price'}, count: {$sum: 1}, avg: {$avg: '$price'} }}, { $match: { count: { $gte: nights } } } ], function (err, result) { if (err) res.send(err); res.json(result); }); });

it homecoming me like:

[ { "_id": "545b4848344044fa3ec9ac74", "total": 180, "count": 2, "avg": 90 } ]

but want homecoming me other field collection don't need/have them in grouping clause eg : available , cost ...

reading mongoose docs understand need utilize $project issue added like:

{$project: {price: "$price"}}

and empty results ... tried adding in $group cause :

price: '$price' no success : "exception: grouping aggregate field 'price' must defined look within object", goggled errors without success how should accomplish this?

you add together them $group, need utilize 1 of accumulator operators determine how want multiple values per _id (roomid) reduced single value.

if think it, adding price: "$price" makes no sense cost value expect use?

so need like:

price: {$first: '$price'} // utilize first cost roomid (be sure sort)

or

price: {$push: '$price'} // set of prices roomid array

or

price: [$max: '$price'} // utilize maximum of prices roomid

etc...hopefully idea.

node.js mongodb mongoose mongodb-query