我正致力于在MongoDB中开发一个管道，它将每个州的公司的所有number_of_employees相加，并打印出每个州的信息。集合结构的基本原理如下所示:"name":"AdventNet","number_of_employees":600,"offices":[{"description":"Headquarters","address1":"4900HopyardRd.","address2":"Suite310","zip_code":"94588","city":"Pleasanton","state_code":"CA","country_code":"USA","la
我有一个这样的集合:[{"_id":1,"OtherProperties":100"PersonInventory":[{"FirstName":"Joe","MiddleName":"Bob","LastName":"Blogs","PersonId":1}]},{"_id":2,"OtherProperties":1005"PersonInventory":[{"FirstName":"Joe","MiddleName":"Bob","LastName":"Blogs","PersonId":1}]}]我正在尝试使用此处较新的类型推断mongodbc#驱动程序语法来选择根文档中的所
查询:db.trace.aggregate([{$unwind:"$likes"},{$group:{_id:{"name":"$name"}}}]);Mongo集合:"likes":[{"category":"test1","name":"test1","created_time":"2014-01-08T20:50:02+0000","id":"14157481053234234"},{"category":"Publisher","name":"CityPulse","created_time":"2014-01-06T22:46:19+0000","id":"169217625
我正在使用聚合管道编写Mongo查询。在聚合期间，我需要$unwind字段之一。但是，我不希望$unwind排除该字段具有零长度数组的条目，因为我仍然需要它们进一步向下流水线。我的字段名为items，它是一个对象数组，每个对象包含两个值:quantity和price。到目前为止，这是我的Mongo查询的一个片段:db.MyCollection.aggregate([{$match:...},{$project:...},//putanother$projectheretoretainzero-lengthvalues?howtoformatit?{$project:{_id:"$$RO
我收集了以下数据:{"_id":ObjectId("51f1fcc08188d3117c6da351"),"cust_id":"abc123","ord_date":ISODate("2012-10-03T18:30:00Z"),"status":"A","price":25,"items":[{"sku":"ggg","qty":7,"price":2.5},{"sku":"ppp","qty":5,"price":2.5}]}我正在使用查询:cmd{"aggregate":"orders","pipeline":[{"$unwind":"$items"},{"$match":{"i
我有一个mongo查询，用于展开四个对象数组并根据匹配条件过滤数据。我如何在Springdatamongodb中执行相同的操作我曾使用过单一展开，但找不到任何具有多个展开和匹配操作的。db.generator.aggregate([{$unwind:'$eCList'},{$unwind:'$pcList'},{$unwind:'$cityList'},{$unwind:'$eATypeList'},{$match:{'eCList.eCCode':{$eq:'enccode1'}}},{$match:{'pcList.pcCode':{$eq:'pccode1'}}},{$match
我想要$unwind2个字段，school和home。数据库结构是这样的；{"id":1,"school":[{"path":"school1","code":"code1",},{"path":"school2","code":"code2",},{"path":"school3","code":"code3",},{"path":"school4","code":"code4",}],"home":[{"path":"home1","code":"homeCode1",},{"path":"home2","code":"homeCode2",},]}我想要$unwindschool
我想按指定字段的相同值对数组中的对象进行分组并生成一个计数。我有以下mongodb文档(不存在不相关的字段)。{arrayField:[{fieldA:value1,...otherFields},{fieldA:value2,...otherFields},{fieldA:value2,...otherFields}],...otherFields}下面是我想要的。{arrayField:[{fieldA:value1,...otherFields},{fieldA:value2,...otherFields},{fieldA:value2,...otherFields}],newA
我有一个MongoDB集合[Users]，每个集合都有一个嵌入式文档数组[Photos]。我希望能够有一个页面列出最近的照片，例如-任何用户最近上传的10张照片。用户[{_id:ObjectIDname:"Matthew"Photos:[{_id:ObjectIDurl:"http://www.example.com/photo1.jpg"created:Date("2013-02-01")},{_id:ObjectIDurl:"http://www.example.com/photo3.jpg"created:Date("2013-02-03")}]},{_id:ObjectIDna
这是我的问题:在我的Mongo数据库中，我有一个包含以下项目的集合:{'id':1,'steps':[{action:'start',info:'foo'},{action:'stop',info:'bar'}]}我想获得“开始”的总步数。我尝试使用MongoDB聚合框架:我使用$unwind在steps.action和$match在steps.action匹配“开始”。但是，我获得了太多数据并达到了聚合的限制:exception:aggregationresultexceedsmaximumdocumentsize(16MB).我不需要数据，我只需要计数，但我找不到如何操作(尝试使用
