我几天来一直在解决这个问题。我有以下订单架构：
order_no: Number,
timestamp: { type: Date, default: Date.now },
total: Number,
details: [
item: String,
price: Number,
qty: Number,
amt: Number
]
Orders集合的示例：
[ {
"order_no": 1,
"details": [
{
"item": "Product A",
"amt": 90,
"qty": 1,
"price": 90,
"_id": "58af49c63107ebf7cda2e5fb"
}
],
"timestamp": "2017-02-23T20:44:54.171Z"
},
{
"order_no": 2,
"total": 95,
"details": [
{
"item": "Product B",
"amt": 95,
"qty": 1,
"price": 95,
"_id": "58af4a618fbad6f7fca6f9c3"
}
],
"timestamp": "2017-02-23T20:47:29.016Z"
},
{
"order_no": 3,
"total": 455,
"details": [
{
"item": "Product A",
"amt": 180,
"qty": 2,
"price": 90,
"_id": "58af4a818fbad6f7fca6f9ca"
},
{
"item": "Product C",
"amt": 90,
"qty": 1,
"price": 90,
"_id": "58af4a818fbad6f7fca6f9c9"
},
{
"item": "Product B",
"qty": 1,
"price": 95,
"amt": 95,
"_id": "58af4a818fbad6f7fca6f9c8"
},
{
"item": "Product D",
"amt": 90,
"qty": 1,
"price": 90,
"_id": "58af4a818fbad6f7fca6f9c7"
}
],
"timestamp": "2017-02-23T20:48:01.157Z"
},
{
"order_no": 4,
"total": 190,
"details": [
{
"item": "Product B",
"amt": 190,
"qty": 2,
"price": 95,
"_id": "58afd1b7ef77dbfdce1fdb65"
}
],
"timestamp": "2017-02-24T06:24:55.121Z"
},
{
"order_no": 5,
"total": 190,
"details": [
{
"item": "Product B",
"qty": 2,
"price": 95,
"amt": 190,
"_id": "58afd26b1d7b73fe06cb7d30"
}
],
"timestamp": "2017-02-24T06:27:55.452Z"
},
{
"order_no": 6,
"total": 95,
"details": [
{
"item": "Product B",
"qty": 1,
"price": 95,
"amt": 95,
"_id": "58afd2de230c85fe34af8018"
}
],
"timestamp": "2017-02-24T06:29:50.115Z"
},
{
"order_no": 7,
"total": 95,
"details": [
{
"item": "Product B",
"qty": 1,
"price": 95,
"amt": 95,
"_id": "58afd30cd123befe49cfe30d"
}
],
"timestamp": "2017-02-24T06:30:36.947Z"
},
{
"order_no": 8,
"total": 95,
"details": [
{
"item": "Product B",
"qty": 1,
"price": 95,
"amt": 95,
"_id": "58afd372fed156fe67ff00a9"
}
],
"timestamp": "2017-02-24T06:32:18.219Z"
},
{
"order_no": 9,
"total": 95,
"details": [
{
"item": "Product B",
"qty": 1,
"price": 95,
"amt": 95,
"_id": "58afd3c4a64da9fe849e3281"
}
],
"timestamp": "2017-02-24T06:33:40.555Z"
},
{
"order_no": 10,
"total": 540,
"details": [
{
"item": "Product A",
"price": 90,
"amt": 540,
"qty": 6,
"_id": "58afd3d2a64da9fe849e3283"
}
],
"timestamp": "2017-02-24T06:33:54.184Z"
},
{
"order_no": 11,
"total": 540,
"details": [
{
"item": "Product C",
"amt": 90,
"qty": 1,
"price": 90,
"_id": "58afef53a64da9fe849e328a"
},
{
"item": "Product E",
"amt": 90,
"qty": 1,
"price": 90,
"_id": "58afef53a64da9fe849e3289"
},
{
"item": "Product F",
"amt": 90,
"qty": 1,
"price": 90,
"_id": "58afef53a64da9fe849e3288"
},
{
"item": "Product A",
"price": 90,
"amt": 270,
"qty": 2,
"_id": "58afef53a64da9fe849e3287"
}
],
"timestamp": "2017-02-24T08:31:15.154Z"
},
{
"order_no": 12,
"total": 90,
"details": [
{
"item": "Product A",
"price": 90,
"amt": 90,
"qty": 1,
"_id": "58b000daa64da9fe849e328c"
}
],
"timestamp": "2017-02-24T09:46:02.968Z"
},
{
"order_no": 13,
"total": 90,
"details": [
{
"item": "Product D",
"amt": 90,
"qty": 1,
"price": 90,
"_id": "58b000e7a64da9fe849e328e"
}
],
"timestamp": "2017-02-24T09:46:15.359Z"
},
{
"order_no": 14,
"total": 235,
"details": [
{
"item": "Product E",
"amt": 90,
"qty": 1,
"price": 90,
"_id": "58b000eea64da9fe849e3293"
},
{
"item": "Product F",
"amt": 90,
"qty": 1,
"price": 90,
"_id": "58b000eea64da9fe849e3292"
},
{
"item": "Product G",
"amt": 55,
"qty": 1,
"price": 55,
"_id": "58b000eea64da9fe849e3291"
}
],
"timestamp": "2017-02-24T09:46:22.047Z"
},
{
"order_no": 1,
"total": 275,
"details": [
{
"item": "Product A",
"price": 90,
"amt": 180,
"qty": 2,
"_id": "58b1e56dcf91ba1d8886ea30"
},
{
"item": "Product B",
"amt": 95,
"qty": 1,
"price": 95,
"_id": "58b1e56dcf91ba1d8886ea2f"
}
],
"timestamp": "2017-02-25T20:13:33.190Z"
},
{
"order_no": 2,
"total": 180,
"details": [
{
"item": "Product E",
"amt": 90,
"qty": 1,
"price": 90,
"_id": "58b1e578cf91ba1d8886ea35"
},
{
"item": "Product F",
"amt": 90,
"qty": 1,
"price": 90,
"_id": "58b1e578cf91ba1d8886ea34"
}
],
"timestamp": "2017-02-25T20:13:44.254Z"
},
{
"order_no": 3,
"total": 235,
"details": [
{
"item": "Product D",
"amt": 90,
"qty": 1,
"price": 90,
"_id": "58b1e58ecf91ba1d8886ea3d"
},
{
"item": "Product G",
"amt": 55,
"qty": 1,
"price": 55,
"_id": "58b1e58ecf91ba1d8886ea3c"
},
{
"item": "Product E",
"qty": 1,
"price": 90,
"amt": 90,
"_id": "58b1e58ecf91ba1d8886ea3b"
}
],
"timestamp": "2017-02-25T20:14:06.161Z"
}]
我如何进行聚合输出以下内容：
{
"_id": {
"day": 24, "month": 2, "year": 2017
},
"products": [
item: "Product A", totalqty: 3, totalamt: 270,
item: "Product B", totalqty: 2, totalamt: 180,
item: "Product C", totalqty: 1, totalamt: 90,
item: "Product D", totalqty: 5, totalamt: 450,
]
},
{
"_id": {
"day": 25, "month": 2, "year": 2017
},
"products": [
item: "Product A", totalqty: 1, totalamt: 90,
item: "Product B", totalqty: 2, totalamt: 180,
item: "Product C", totalqty: 3, totalamt: 270,
]
}, etc, etc
请帮助我找一下如何对每个日期进行分组，并列出每种产品的总数量和总量。
答案 0 :(得分：3)
您可以尝试以下聚合。
$unwind详细信息，首先$group timestamp和item，然后按$group计算总数量和金额以及最终timestamp将具有先前计算的数量和金额值的项目推送到products。
db.orders.aggregate({
$unwind: "$details"
}, {
$group: {
_id: {
month: {$month: "$timestamp"},
day: {$dayOfMonth: "$timestamp"},
year: {$year: "$timestamp"},
item: "$details.item"
},
totalqty: {$sum: "$details.qty"},
totalamt: {$sum: "$details.amt"}
}
}, {
$group: {
_id: {
month: "$_id.month",
day: "$_id.day",
year: "$_id.year"
},
products: {
$push: {
item: "$_id.item",
totalqty: "$totalqty",
totalamt: "$totalamt"
}
}
}
})
答案 1 :(得分：1)
如果你正在使用mongoose，这就是整体解决方案：
然后您可以按照@ Veeram的解决方案，首先需要unwind details数组将每个细节项目转换为新文档。然后，您可以按产品ID和日期对文档进行分组（此处我们使用聚合框架＆＃date}帮助函数，例如$month，$dayOfMonth和$year）。最后，如果您需要将一天的所有产品放在一个数组下，您可以groupBy天。您可以通过官方文档详细了解groupBy如何合作：https://docs.mongodb.com/manual/reference/operator/aggregation/group/
const Promise = require("bluebird");
const mongoose = require("mongoose");
mongoose.connect('mongodb://localhost/myapp');
const schema = {
order_no: Number,
timestamp: {type: Date, default: Date.now},
total: Number,
details: [{
item: String,
price: Number,
qty: Number,
amt: Number
}]
};
const ordersSchema = new mongoose.Schema(schema, {collection: "orders"});
const ordersCollection = mongoose.model("Orders", ordersSchema);
const aggregations = [];
aggregations.push({$unwind: "$details"});
aggregations.push({
$group: {
_id: {
month: {$month: "$timestamp"},
day: {$dayOfMonth: "$timestamp"},
year: {$year: "$timestamp"},
productId: "$details.item"
},
totalQuantity: {$sum: "$details.qty"},
totalAmount: {$sum: "$details.amt"}
}
});
aggregations.push({
$group: {
_id: {month: "$_id.month", day: "$_id.day", year: "$_id.year"},
productSummaries: {
$push: {
item: "$_id.productId",
totalQuantity: "$totalqty",
totalAmount: "$totalamt"
}
}
}
});
ordersCollection.aggregate(aggregations).then(results => results.forEach(result => console.log(result))).catch(err => console.error(err));