how to group data based on months in nodejs? - node.js

Question

Sale.aggregate({
$match: filter
}, {
$group: {
"_id": {
"store_id": "$store_id",
//"created_on": { $dateToString: { format: "%Y-%m-%d", date: "$strBillDate" } }
},
month: {
$month: "$strBillDate"
},
store_id: {
$first: "$store_id"
},
strBillAmt: {
$sum: "$strBillAmt"
},
strBillNumber: {
$sum: 1
}
}
})
Instead of date, I need to group sales in months, how to group sales in months in nodejs

Answer 1

I used a projection first in the aggregate chain to extract monthly and yearly values and did the grouping afterwards:
<doc-name>.aggregate([
{ $project:
{ _id: 1,
year: { $year: "$date" },
month: { $month: "$date"},
amount: 1
}
},
{ $group:
{ _id: { year: "$year", month: "$month" },
sum: { $sum: "$amount" }
}
}])
I also tried with your model:
var testSchema = mongoose.Schema({
store_id: { type: String },
strBillNumber: { type: String },
strBillDate: { type: Date },
strBillAmt: { type: Number }
});
var Test = mongoose.model("Test", testSchema);
Create some test data:
var test = new Test({
store_id: "1",
strBillNumber: "123",
strBillDate: new Date("2016-04-02"),
strBillAmt: 25
});
var test2 = new Test({
store_id: "1",
strBillNumber: "124",
strBillDate: new Date("2016-04-01"),
strBillAmt: 41
});
var test3 = new Test({
store_id: "3",
strBillNumber: "125",
strBillDate: new Date("2016-05-13"),
strBillAmt: 77
});
Run the query:
Test.aggregate([
{ $project:
{ store_id: 1,
yearBillDate: { $year: "$strBillDate" },
monthBillDate: { $month: "$strBillDate" },
strBillAmt: 1
}
},
{ $group:
{ _id: {yearBillDate: "$yearBillDate", monthBillDate:"$monthBillDate"},
sum: { $sum: "$strBillAmt" }
}
}
], function(err, result) {
console.log(err, result)});
And got a reasonable result: