假设我有这样一个文档:{"_id":ObjectId("57eb386e37b4842ff5f386c9"),"lesson_id":ObjectId("57e27cd190e6993e393f5c74"),"student_id":ObjectId("57d3c3f590e6995fe8de7932"),"answer_records":{"1":{"answer":["A"]},"3":{"answer":["C"]}}我想统计集合中答案记录的数量。显然，这份文件贡献了两条答复记录，分别是“1”和“3”。所以，我的问题是如何使用聚合管道实现这一目标。 最
Document:{"version":"1.0.0","actor":{"objectType":"Agent","name":"Testuser","account":{"homePage":"http://testing.com/","name":"67"}},"verb":{"id":"http://adlnet.gov/expapi/verbs/completed","display":{"en-US":"completed"}},"object":{"objectType":"Activity","id":"http://localhost/action?id=cji","
我正在尝试使用$sum计算每个州的总数。然后使用$lt仅显示小于100的状态。每笔总和:db.zipcode.aggregate([{$group:{_id:"$state",count_of_cities:{$sum:1}}}])尝试显示小于100的总和:db.zipcode.aggregate([{$group:{_id:"$state"},less_than:{$cond:{if:{$lt:[$sum:1,100]}}}}])样本收集:{"_id":"01001","city":"AGAWAM","loc":[-72.622739,42.070206],"pop":15338,"
我有这样的集合架构:{"_id":ObjectId("582ee289618a504e5c830e03"),"updatedAt":ISODate("2016-11-24T05:01:59.470Z"),"createdAt":ISODate("2016-11-18T11:14:17.912Z"),"requestId":"IER5R2H","pickupDetails":{"_id":ObjectId("58367447b0a1ada74ad7af7e"),"itemsCount":1,"pickupItems":[{"name":"Newspaper","quantity":15,
我得到了一个包含这些文档的集合:{"_id":0,"pictures":[{"path":"/path/to/first/picture.jpg","web":"true"},{"path":"/path/to/second/picture.jpg","web":"true",}],"logos":[{"path":"/path/to/first/logo.jpg","web":"true"},{"path":"/path/to/second/logo.jpg","web":"false",}]}{"_id":1,"pictures":[{"path":"/a/bit/weird/pa
我有一个集合“评论”如下:{comment_id:10001aspects:[{name:'aspectA',positive:2negative:3neutral:1},{name:'aspectB',positive:1negative:5neutral:3}},{comment_id:10002aspects:{name:'aspectA',positive:2negative:1neutral:2},{name:'aspectB',positive:3negative:4neutral:1}}]评论中的文档数大于100K。我必须找到所有方面的正面、负面和中性的数量，即。所有文档
鉴于以下文件。{_id:1,ExpirationDate:ISODate("2017-05-02T09:29:46.006+0000")}{_id:2,ExpirationDate:ISODate("2017-05-12T09:29:46.006+0000")}{_id:3,ExpirationDate:ISODate("2017-05-23T09:29:46.006+0000")}如何使用聚合管道计算以下输出？{"NumberOfSubscriptionExpiringToday":12,"NumberOfSubscriptionExpiringWithInAWeek":4}我希望只
mongo中的数据:enterimagedescriptionheredb.test2.aggregate([{"$project":{"contents":1,"comments":{"$filter":{"input":"$comments","as":"item","cond":{"$gt":['$$item.score',2]}},},"comments2":{"$filter":{"input":"$comments2","as":"item","cond":{"$gt":["$$item.score",5]}}}}},{"$project":{"content":1,"co
我有一些市场提要数据，我正尝试在Ubuntu16.04上使用mongodb3.4.5在给定的日期范围内生成一个很好的摘要。这是一个示例文档。每个文档可能包含多个批量数据，包括买入、卖出和填写。{"MarketName":"BIX","Nounce":12040,"Buys":[{"Type":2,"Rate":0.08068147,"Quantity":55.57280163},{"Type":1,"Rate":0.07980372,"Quantity":0},{"Type":0,"Rate":0.07962334,"Quantity":34.96018931},{"Type":1,"
我知道python-eve支持aggregation和filtering.我知道如何分别使用它们:$curl-ihttp://example.com/posts?aggregate={"$value":2}http://eve-demo.herokuapp.com/people?where={"lastname":"Doe"}但问题是:我可以同时使用它们吗？例如，我定义了一个端点:posts={'datasource':{'aggregation':{'pipeline':[{"$unwind":"$tags"},{"$group":{"_id":"$tags","count":{"$
