如何在$ match聚合中找到值数组并将结果分组?

(price_total: {$ multiply: [" $toys.price", quantify]})我想按商店对结果进行分组，并显示商店引用了多少玩具，其输出如下:[ { "_id": "Toystore A", "total_coincidences":2 "toy_array": [ { "total":1,// "total":1, //1 time is founded this toy in array filter "price_original": 500, "toy": "buzz", "price_total":1000 // 2 * 500=1000 (price total) }, { "total":1,// "total":1, //1 time is founded this toy in array filter "price_original": 300, "toy": "pope", "price_total":1200 // 4 * 300= 1200(price total) } ] }, { "_id": "Toystore B", "total":1, //1 element distinct is founded "toy_array": [ { "total":2, //two times is founded this toy in array filter "price_original": 500, "toy": "jessie" "price_total":5500 //this toy is two times in the filter array // 5 * 500 = 2500 // 6 * 500 = 3000 //3000+ 2500=5500 (price total) } ] }]这是我的代码:db.collection.aggregate([ { $unwind: "$toys" }, { $match: { $or: [ { "toys.code": 17001 }, { "toys.code": 17003 }, { "toys.code": 17005 }, { "toys.code": 17005 } ], } }, { $group: { _id: "$toystore_name", toy_array: { $push: { price_original: "$toys.price", /* price_total: { $multiply: ["$toys.price", qunantify] }*/ toy: "$toys.toy" }, }, }, }, ])这是我的实时代码:解决方案您需要如下所示更改filters.说明我们使用$addFields运算符将过滤器包含在文档结构中.这将帮助我们计算所有必要的值.我们使用$expr运算符使用最近包含的filters属性过滤toys.应用$filter运算符，从filters中获得所有具有相同code的玩具.现在，我们可以计算total和price_total值.我们可以像这样在$group阶段内计算total_coincidences: total_coincidences:{$ sum:1}但是，您提到了独特元素".因此，我们创建了一组唯一的玩具代码并计算了其中的项目.db.collection.aggregate([ { $unwind: "$toys" }, { $addFields: { "filters": [ { "code": 17001, "quantify": 2 }, { "code": 17003, "quantify": 4 }, { "code": 17005, "quantify": 5 }, { "code": 17005, "quantify": 6 } ] } }, { $match: { $expr: { $in: [ "$toys.code", "$filters.code"] } } }, { $group: { _id: "$toystore_name", total_coincidences: { $addToSet: "$toys.code" }, toy_array: { $push: { "price_original": "$toys.price", "toy": "$toys.toy", "total": { $size: { $filter: { input: "$filters", cond: { $eq: [ "$$this.code", "$toys.code"] } } } }, price_total: { $sum: { $map: { input: { $filter: { input: "$filters", cond: { $eq: [ "$$this.code", "$toys.code" ] } } }, in: { $multiply: [ "$toys.price", "$$this.quantify" ] } } } } } } } }, { $addFields: { total_coincidences: { $size: "$total_coincidences" } } }, { $sort: { _id: 1 } }]) MongoPlayground Note:I think it is not possible to use javascript code in this live editorthis is my live code: https://mongoplayground.net/p/IM4rY2K7AltI am new to Mongodb I have a lot of faith to understand this exercise to understand more about the topic ofaggregationsMy problem is this. I have a collection with a structure like this:[ { "toystore": 22, "toystore_name": "Toystore A", "toys": [ { "toy": "buzz", "code": 17001, "price": 500 }, { "toy": "woddy", "code": 17002, "price": 1000 }, { "toy": "pope", "code": 17003, "price": 300 } ] }, { "toystore": 11, "toystore_name": "Toystore B", "toys": [ { "toy": "jessie", "code": 17005, "price": 500 }, { "toy": "rex", "code": 17006, "price": 2000 } ] } ]I have n toy stores, and within each toy store I have the toys that this store has available within thetoys field (is an array).I receive a list of the toys that I want to look for in all the stores and the quantify of toys that I need to quote. var originalData=[ { "toys.code": 17001, "quantify":2 }, { "toys.code": 17003, "quantify":4 }, { "toys.code": 17005, "quantify":5 }, { "toys.code": 17005, "quantify":6 } ]I'm using javascript, so I manage to create an array like this: let filters = []; originalData.forEach((data) => { filters.push({ "toys.code": data.code }); });//outputfilters= [ { "toys.code": 17001 }, { "toys.code": 17003 }, { "toys.code": 17005 }, { "toys.code": 17005 } ]//in the live code I do this simulation/*$match: { $or: filters}*//*$match: { $or: [ { "toys.code": 17001 }, { "toys.code": 17003 }, { "toys.code": 17005 }, { "toys.code": 17005 } ],*/to search for toys (I search for toys by their code toys.code), here I have my first problem, I don't know how to pass thequantity and then get the total price of the toys(price_total: {$ multiply: [" $toys.price", quantify]})I would like to group the result by store, and show how many toys were quoted by store with an output like this:[ { "_id": "Toystore A", "total_coincidences":2 "toy_array": [ { "total":1,// "total":1, //1 time is founded this toy in array filter "price_original": 500, "toy": "buzz", "price_total":1000 // 2 * 500=1000 (price total) }, { "total":1,// "total":1, //1 time is founded this toy in array filter "price_original": 300, "toy": "pope", "price_total":1200 // 4 * 300= 1200(price total) } ] }, { "_id": "Toystore B", "total":1, //1 element distinct is founded "toy_array": [ { "total":2, //two times is founded this toy in array filter "price_original": 500, "toy": "jessie" "price_total":5500 //this toy is two times in the filter array // 5 * 500 = 2500 // 6 * 500 = 3000 //3000+ 2500=5500 (price total) } ] }]this is my code:db.collection.aggregate([ { $unwind: "$toys" }, { $match: { $or: [ { "toys.code": 17001 }, { "toys.code": 17003 }, { "toys.code": 17005 }, { "toys.code": 17005 } ], } }, { $group: { _id: "$toystore_name", toy_array: { $push: { price_original: "$toys.price", /* price_total: { $multiply: ["$toys.price", qunantify] }*/ toy: "$toys.toy" }, }, }, }, ])and this is my live code: 解决方案 You need to change your filters as shown below.ExplanationWe include filters in the document structure with the $addFields operator. This will help us calculate all the necessary values.We filter toys with the recent included filters attribute with the $expr operator.Applying the $filter operator, we get all toys with the same code from filters. Now, we can calculate total and price_total values.We could calculate total_coincidences inside the $group stage like this: total_coincidences : {$sum:1}But, you've mentioned "distinct element". So, we create set of unique toy codes and count items in the set.db.collection.aggregate([ { $unwind: "$toys" }, { $addFields: { "filters": [ { "code": 17001, "quantify": 2 }, { "code": 17003, "quantify": 4 }, { "code": 17005, "quantify": 5 }, { "code": 17005, "quantify": 6 } ] } }, { $match: { $expr: { $in: [ "$toys.code", "$filters.code"] } } }, { $group: { _id: "$toystore_name", total_coincidences: { $addToSet: "$toys.code" }, toy_array: { $push: { "price_original": "$toys.price", "toy": "$toys.toy", "total": { $size: { $filter: { input: "$filters", cond: { $eq: [ "$$this.code", "$toys.code"] } } } }, price_total: { $sum: { $map: { input: { $filter: { input: "$filters", cond: { $eq: [ "$$this.code", "$toys.code" ] } } }, in: { $multiply: [ "$toys.price", "$$this.quantify" ] } } } } } } } }, { $addFields: { total_coincidences: { $size: "$total_coincidences" } } }, { $sort: { _id: 1 } }])MongoPlayground 这篇关于如何在$ match聚合中找到值数组并将结果分组?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！