我有2个类:@Document(collection="student")publicclassMongoStudent{@IdprivateBigIntegerid;@Field("name")privateStringname;@Field("lname")privateStringlname;@Field("studium")privateListstudium;@PersistenceConstructorpublicMongoStudent(BigIntegerid,Stringname,Stringlname,Liststudium){this.id=id;this.nam

我已经部署了一个FIWARE配置来接收来自TheThingsNetwork的MQTT消息。该配置使用IoTAgent-JSON、Orion和Cygnus，以及用于Cygnus的MongoDB后端。消息已正确保存到MongoDB。不幸的是，消息数据具有层次结构，消息的某些部分在MongoDB中显示为字符串，而不是嵌入的子文档。这使得查询数据变得困难。详情如下:消息格式由TTNMQTTDataAPI定义.我在Orion上定义了一个实体类型，如下所示:curlhttp://localhost:1026/v2/entities-XPOST-H"content-type:application/

我有一些代码可以从集合中提取所有文档并将其放到网页上。简化版本如下所示:varmongodb=require("mongodb"),express=require("express"),mongoServer=newmongodb.Server('localhost',27017),dbConnector=newmongodb.Db('systemMonitor',mongoServer),db;varapp=newexpress();app.get('/drives',function(req,res){db.collection('driveInfo',function(err,c

我正在尝试解决在SqlServer中需要公用表表达式或子查询的问题。我有一个名为Invoice_Details的集合。每个文档都有一个InvoiceID、CustomerID、TransactionDate和TransactionAmount字段。我想要做的是取回当TransactionAmount聚合时不等于零的所有文档。我正在做如下分组:db.Invoice_Details.aggregate([{$group:{_id:{InvoiceID:"$InvoiceID"},Balance:{$sum:"$TransactionAmount"}}},{$match:{Balance:{

我有用户的集合，这是以下文件:{"_id":1,"name":"A","online":1,"like":10,"score":1},{"_id":2,"name":"B","online":0,"like":9,"score":0},{"_id":3,"name":"C","online":0,"like":8,"score":1},{"_id":4,"name":"D","online":1,"like":8,"score":0},{"_id":5,"name":"E","online":1,"like":7,"score":1},{"_id":6,"name":"F","onli

我正在使用如下聚合:finalListaggregations=newArrayList();Polygonpolygon=newPolygon(newPoint(-26.28125,42.19231862526141),newPoint(100.28125,64.7157757187955),newPoint(100.28125,42.19231862526141),newPoint(-26.28125,64.7157757187955));AggregationOperationmatch=newMatchOperation(Criteria.where("location").w

我想启动这个MongoDB副本集:version:"3"services:mongo1:image:mongoports:-27017:27017command:mongod--replSetrs0mongo2:image:mongoports:-27018:27017command:mongod--replSetrs0mongo3:image:mongoports:-27019:27017command:mongod--replSetrs0等待它们出现，然后通过终端访问Mongoshell:dockerexec-itmongo1mongo然后在Mongoshell中执行:rs.ini

在我的项目中，我使用了spring-boot和嵌入式MongoDb，查看我的pom.xml文件:4.0.0com.defaultdefault0.0.1-SNAPSHOTjardefaultDemoprojectforSpringBootorg.springframework.bootspring-boot-starter-parent2.0.1.RELEASEUTF-8UTF-81.7truede.flapdoodle.embedde.flapdoodle.embed.mongo1.50.5cz.jirutka.springembedmongo-springRELEASEorg.sp

我将MongoDB与SpringBoot2.0和SpringData结合使用。我对MongoDB有以下请求{"cra":"test-cra","service":"test-service","timestamp":"2012-04-23T18:25:43.511Z","parameters":[{"name":"test-param-name1","value":"test-param-value1"}]}在MongoDB中，例如我有以下文档:{"cra":"test-cra","service":"test-service","timestamp":"2012-04-23T18:2

如何从具有以下结构的Mongo文档的数组中获取一个元素:{array:[{type:'cat',name:'George'}{type:'cat',name:'Mary'}{type:'dog',name:'Steve'}{type:'dog',name:'Anna'}]}例如我需要得到史蒂夫，在这种情况下结果必须是这样的:{array:[{type:'dog',name:'Steve'}]}左右:{type:'dog',name:'Steve'}我知道如何在发布时制作它，但我需要在整个数组可用的客户端制作它，我可以使用forEach从数组返回这个值，但我正在寻找更优雅的方式(使用Mo