Mongoose: I need to calculate totalizer for some fields in aggregate - node.js

Question

I have a query (aggregate) and I need to calculate a totalizer for some fields (value and comissionValue) and count how many registers this query have.
My query(aggregate)
let findTerm = {
store: req.body.store,
status: {
$in: resultStatusServices
}
}
if (req.body.start) {
findTerm.scheduleStart = {
$lte: req.body.start
};
}
if (req.body.period) {
findTerm.scheduleEnd = {
$gte: req.body.period
};
}
Schedule.aggregate([{
$match: findTerm
},
{
$project: {
"employee.name": 1,
"customer.name": 1,
"service.name": 1,
"value": 1,
"scheduleDate": 1,
"scheduleStart": 1,
"scheduleEnd": 1,
"comissionValue": 1,
"status": 1,
"paymentMethod": 1
}
},
{
$group:{
_id: {
"employee.name" : "$employee.name",
"customer.name" : "$customer.name",
"service.name": "$service.name",
"value": "$value",
"scheduleDate": "$scheduleDate",
"scheduleStart" :"$scheduleStart",
"scheduleEnd": "$scheduleEnd",
"comissionValue" : "$comissionValue",
"status" : "$value",
"paymentMethod" : "$paymentMethod"
},
}
},
{
$match: findTerm
},
{
$group: {
_id: {
id: "$store"
},
totalValue: {
$sum: "$value"
},
totalServices: {
"$sum": 1
},
totalComission: {
$sum: "$comissionValue"
},
count: {
$sum: 1
}
}
},
{
$sort: sort
},
{
$skip: req.body.limit * req.body.page
},
{
$limit: req.body.limit
}
Schedule (model)
store: {
type: String,
required: true
},
customer: {
id: {
type: String
},
name: {
type: String
},
avatar: String,
phone: {
type: String
},
email: { type: String },
doc: {
type: String
},
},
employee: {
id: {
type: String,
required: true
},
name: {
type: String,
required: true
},
avatar: String,
},
service: {
id: {
type: String
},
name: {
type: String,
required: true
},
filters: [String]
},
info: {
channel: {
type: String,
required: true,
default: 'app'
},
id: String,
name: String
},
scheduleDate: {
type: String,
required: true
},
scheduleStart: {
type: String,
required: true
},
scheduleEnd: {
type: String,
required: true
},
value: {
type: Number
},
comissionType: {
type: String,
default: '$'
},
comissionValue: {
type: Number,
default: 0
},
status: {
type: Number,
required: true
},
observation: String,
paymentMethod: {
type: Number,
default: 0
},
What I'am trying to do as a result of this query:
[
0:{
comissionValue: 14
customer: {name: "Marcelo"}
employee: {name: "Andy"}
paymentMethod: 0
scheduleDate: "2019-01-01"
scheduleEnd: "2019-01-01 09:30"
scheduleStart: "2019-01-01 09:00"
service: {name: "Barber"}
status: 2
value: 20
_id: "5c26275ffe046d25a07cb466"}
1: {...}
2: {...}
...
],[totalizers: { count: 2, totalServices: 50, totalComission:65}]
How can i do this, how can i make this totalizers?

Answer 1

You can use $facet to accomplish this type of query since it allows you to run various aggregations on the same set of input documents, without needing to retrieve the input documents multiple times. The first facet can have the query pipeline with the sort and limit and the other facet will yield the aggregate sums (totalizers).
For instance the following aggregate operation will give you the desired result:
Schedule.aggregate([
{ '$match': findTerm },
{ '$facet': {
'data': [
{ '$project': {
'employee.name': 1,
'customer.name': 1,
'service.name': 1,
'value': 1,
'scheduleDate': 1,
'scheduleStart': 1,
'scheduleEnd': 1,
'comissionValue': 1,
'status': 1,
'paymentMethod': 1
} },
{ '$sort': sort },
{ '$skip': req.body.limit * req.body.page },
{ '$limit': req.body.limit }
],
'totalizer': [
{ '$group': {
'_id': '$store',
'count': { '$sum': 1 },
'totalValue': { '$sum': '$value' },
'totalComission': { '$sum': '$comissionValue' }
} },
{ '$group': {
'_id': null,
'storesCount': {
'$push': {
'store': '$_id',
'count': '$count'
}
},
'totalValue': { '$sum': '$totalValue' },
'totalServices': { '$sum': '$count' },
'totalComission': { '$sum': '$totalComission' }
} }
]
} }
]).exec((err, results) => {
if (err) handleError(err);
console.log(results[0]);
})