我有以下实体集合:publicclassBranch{[BsonId]publicObjectIdId{get;set;}publicstringDescription{get;set;}publicObjectIdPartnerId{get;set;}publicIEnumerableDiscounts{get;set;}}我想按PartnerId分组并选择PartnerId，首先不是nullDescription并连接(SelectMany)组中的所有Discounts数组。基本上所需的结果是一个数组:publicclassGroupProjection{publicObjectI
我尝试按月聚合和分组mongodb中的对象。我基本上是从mongo文档中复制查询。db.users.aggregate({$group:{_id:{month:{$month:"$registrationDate"}},count:{$sum:1}}});registrationDate的类型是日期。用户集合中对象的简短版本。{"_id":ObjectId("50ab08399b57f2be03000000"),..."registrationDate":ISODate("2012-11-20T05:34:01.000Z"),...}然后我得到一个异常exception:can'tco
我有这样的文件:{"_id":ObjectId("565e906bc2209d91c4357b59"),"userEmail":"abc@example.com","subscription":{"project1":{"subscribed":false},"project2":{"subscribed":true}}}{"_id":ObjectId("565e906bc2209d91c4357b59"),"userEmail":"mno@example.com","subscription":{"project1":{"subscribed":true},"project2":{"
我在mongoDB中有一个集合，每天都会向其中添加一个包含采样数据的文档。我想观察字段变化。我想使用mongoDB聚合将彼此相邻的相似项目分组到第一个:+--+-------------------------+|id|field|date|+--+-------------------------+|1|hello|date1|+--+-------------------------+|2|foobar|date2|\_Condensetheseintoonerowwithdate2+--+-------------------------+/|3|foobar|date3|+--
我有一个带有简单文档的集合，用于存储具有以下结构的impressions和conversions:/*1*/{"_id":ObjectId("566f1ef857c1e6dd3123050a"),"path_id":ObjectId("55944c1ebe244fd19cbf510b"),"data_type":"impression","created_at":ISODate("2015-12-14T19:56:40.100Z"),"__v":0}/*2*/{"_id":ObjectId("566f1fc9ac964e6f327c55d6"),"path_id":ObjectId("
我想要实现的目标假设有以下子文档:{"id":1,"url":"mysite.com","views":[{"ip":"1.1.1.1","date":"01-01-2015"},{"ip":"2.2.2.2","date":"01-01-2015"},{"ip":"1.1.1.1","date":"01-01-2015"},{"ip":"1.1.1.1","date":"01-01-2015"}]}我要数:根据"ip"值有多少个IP和还统计"views"中的子文档总数如果可能在同一个查询中，实现以下结果:[{"_id":"2.2.2.2","count":1},{"_id":"1.1
我有一个关于mongodb中的mapReduce框架的查询，所以我有一个来自mapReduce函数的键值对结果，现在我想在mapReduce的这个输出上运行查询。所以我正在使用mapReduce来找出这样的用户统计信息db.order.mapReduce(function(){emit(this.customer,{count:1,orderDate:this.orderDate.interval_start})},function(key,values){varsum=0;varlastOrderDate;values.forEach(function(value){if(value
这是我的收藏:{"user":1,"rate":1,"movie":1}{"user":1,"rate":3,"movie":3}{"user":1,"rate":2,"movie":4}{"user":1,"rate":3,"movie":5}{"user":2,"rate":4,"movie":1}{"user":2,"rate":2,"movie":3}{"user":2,"rate":5,"movie":6}{"user":3,"rate":1,"movie":3}这是我想要得到的结果:{"user1":1,"rate1":1,"user2":2,"rate2":4,"movi
我想在mongoDB中使用组聚合，以便根据文档的创建日期对文档进行分组。我没有将创建日期保存为一个字段，但我知道我可以从我的ObjectId中提取这个日期。所以，我试着写这样的东西:db.sales.aggregate([{$group:{_id:{month:{$month:ObjectId("$_id").getTimestamp()},day:{$dayOfMonth:ObjectId("$_id").getTimestamp()},year:{$year:ObjectId("$_id").getTimestamp()}},averageQuantity:{$avg:"$quan
我收藏的文档结构如下所示:[{sender:'A',recipient:'B',date:NewMongoDate(1),contents:'Blablabla1'},{sender:'B',recipient:'A',date:NewMongoDate(2),contents:'Blablabla2'},{sender:'A',recipient:'C',date:NewMongoDate(4),contents:'Blablabla1'},{sender:'C',recipient:'A',date:NewMongoDate(3),contents:'Blablabla2'}{se
