我正在使用MongoDB，我非常享受!有一个查询我在处理时遇到问题:我有这组表示层次结构的数据(一棵树，其中1是根，1.1和1.2是1的子级，依此类推)db.test.insert({id:1,hierarchy:"1"})db.test.insert({id:2,hierarchy:"1.1"})db.test.insert({id:3,hierarchy:"1.2"})db.test.insert({id:4,hierarchy:"1.1.1"})db.test.insert({id:5,hierarchy:"1.1.2"})db.test.insert({id:6,hierarc
我需要按型号分组产品。每个产品都有模型字段-DBRef到模型集合。我尝试使用此聚合查询，但出现错误FieldPathfieldnamesmaynotstartwith'$'.聚合查询:db.Products.aggregate([{$project:{_id:0,model:1,isActive:1}},{$group:{_id:"$model.$id",actives:{$push:"$isActive"}}}]);产品文档示例:{_id:ObjectId("54f48610e31701d2184dede5"),isActive:true,model:{$db:"database",
对mongo很陌生，在解决这个问题时遇到了一些麻烦。我有这样的收藏{"_id":"PN89dNYYkBBmab3uH","card_id":1,"vote":1,"time":1437700845154}{"_id":"Ldz7N5syeW2SXtQzP","card_id":1,"vote":1,"time":1437700846035}{"_id":"v3XWHHvFSHwYxxk6H","card_id":1,"vote":2,"time":1437700849817}{"_id":"eehcDaCyTdz6Yd2a9","card_id":2,"vote":1,"time":1
这是我的mongo系列“销售”:{"title":"Foo","hash":17,"num_sold":49,"place":"ABC"}{"title":"Bar","hash":18,"num_sold":55,"place":"CDF"}{"title":"Baz","hash":17,"num_sold":55,"place":"JKN"}{"title":"Spam","hash":17,"num_sold":20,"place":"ZSD"}{"title":"Eggs","hash":18,"num_sold":20,"place":"ZDF"}我想按哈希分组并返回具有最
这是我的查询:db.getCollection('design_ideas').aggregate({$match:{'Deals.URL':'warm-up-with-white'}},{$unwind:'$Deals'},{$match:{'Deals.URL':'warm-up-with-white'}},{$group:{_id:'$Deals.URL',Deals:{$addToSet:'$Deals'}}})C#中的相同查询:_mongoDB.GetCollection("design_ideas").Aggregate().Match(BsonDocument.Parse
我在mongoDB中有文档，例如:{"_id":"myId","firstName":"myFirstName","lastName":"myLastName","email":"my@email.com","age":88,"city":"myCity","country":"myCountry"}然后，我在管道中通过_id进行lookup、unwind和group。当我需要所有字段时，有什么方法可以不列出所有字段吗？{$group:{"_id":"$_id","someItemsFromLookup":{"$push":"$someItemsFromLookup"}"firstNa
考虑将这些对象放入db.invoices{"customer":"john","price":4,"weekday":"WED"}{"customer":"john","price":8,"weekday":"SUN"}{"customer":"john","price":6,"weekday":"SAT"}{"customer":"john","price":5,"weekday":"SUN"}{"customer":"bob","price":10,"weekday":"SAT"}{"customer":"bob","price":15,"weekday":"MON"}如何查询每个
我正在努力了解Mongo的整个聚合框架。我在这里有点新手。Ihavethefollowingdocuments:{"col1":"camera","fps":1,"lat":3},{"col1":"camera","fps":3,"lat":2}{"col1":"recorders","fps":9,"lat":7}{"col1":"cell","fps":8,"lat":1}{"col1":"cell","fps":4,"lat":3}如何设置返回结果:{"col1":"camera","fps":4,"lat":5},{"col1":"recorders","fps":9,"lat
我有以下间隔为15分钟的数据。[{"_id":ObjectId("5500a5e6f37a84d0509526ba"),"runtimeMilliSeconds":NumberLong("1426105802063"),"cpuMemoryStats":{"currentCpuUtilization":71.72000122070312,"currentMemoryUtilization":77.4000015258789}}{"_id":ObjectId("5500a96af37a84d0509526f8"),"runtimeMilliSeconds":NumberLong("142
使用PyMongo，一键分组似乎没问题:results=collection.group(key={"scan_status":0},condition={'date':{'$gte':startdate}},initial={"count":0},reduce=reducer)结果:{u'count':215339.0,u'scan_status':u'PENDING'}{u'count':617263.0,u'scan_status':u'DONE'}但是当我尝试按多个键进行分组时出现异常:results=collection.group(key={"scan_status":0,
