标签: aggregation-framework

我有多个类似这样的数据

{
    "_id" : ObjectId("57189fcd72b6e0480ed7a0a9"),
    "venueId" : ObjectId("56ce9ead08daba400d14edc9"),
    "companyId" : ObjectId("56e7d62ecc0b8fc812b2aac5"),
    "cardTypeId" : ObjectId("56cea8acd82cd11004ee67a9"),
    "matchData" : [ 
        {
            "matchId" : ObjectId("57175c25561d87001e666d12"),
            "matchDate" : ISODate("2016-04-08T18:30:00.000Z"),
            "matchTime" : "20:00:00",
            "_id" : ObjectId("57189fcd72b6e0480ed7a0ab"),
            "active" : 3,
            "cancelled" : 0,
            "produced" : 3
        }, 
        {
            "matchId" : ObjectId("57175c25561d87001e666d13"),
            "matchDate" : ISODate("2016-04-09T18:30:00.000Z"),
            "matchTime" : "20:00:00",
            "_id" : ObjectId("57189fcd72b6e0480ed7a0aa"),
            "active" : null,
            "cancelled" : null,
            "produced" : null
        }
    ],
    "__v" : 0
}

我正在做分组companyId并且它的工作很好但是我想matchData 根据matchtime和matchId为此目的进行搜索，我$unwind matchData在放松之后我使用这样的搜索查询 …

我有一个包含两个文档的集合

{
    "_id" : ObjectId("5784def78c669ee061519aaf"),
    "name" : "nithin",
    "sal" : 2000.0,
    "age" : 20.0
},
{
    "_id" : ObjectId("5784def78c669ee061519ab0"),
    "name" : "nithin",
    "sal" : 20.0,
    "age" : 2000.0
}

我想找到给定名字和相应年龄的最小萨尔

在这种情况下，最小 Sal 为 20，相应的年龄为 2000

运行我的查询如下：

db.test.aggregate([{
"$group":{"_id":"$name" ,"minSalary" :{"$min":"$sal"} , "ages":{"$addToSet":{"ageval":"$age","salval":"$sal"}}}}
,{"$project": {
         "_id":0,
          "sal":"$minSalary",
         "ages":  "$ages"
      }
  },
  {
   "$unwind":"$ages"   
   }
   ,
   {
    **"$match":{ "ages.salval":**20** }**  
    }
]
)

但问题是我希望 $match 直接应用于 minSalary 而不是将过滤器值硬编码为 20 。请帮忙

我使用节点在 mongoDB 中创建了类别，为每个插入添加了父属性以确定哪个是父类别。

[{ _id: 5889a06f274afdfd6f2bf249,
    cat_id: 1,
    title: 'Parent Category',
    description: '',
    parent: null,
    status: 1}]

[{ _id: 5889a06f274afdfd6f2bf249,
    cat_id: 1,
    title: 'Child Category',
    description: '',
    parent: 1,
    status: 1}]

现在，当我使用 mongoDB 的 db.find() 方法查询时，输出 json 应该使用 node。

{
  obj: [
  { 
    _id: "5889a06f274afdfd6f2bf249",
    cat_id: 1,
    title: "Parent Category",
    description: "",
    parent: null,
    status: 1, 
    subcategories: [
      { 
        _id: "5889a06f274afdfd6f2bf249",
        cat_id: 1,
        title: "Child Category",
        description: "",
        parent: 1,
        status: 1

      }
    ]

  }
]}

我是猫鼬的新手。我有这样的模型。

var ForumSchema = new mongoose.Schema({
User_id             : {type : Schema.Types.ObjectId, ref : 'User'},
Title               : {type : String},
Content             : {type : String},
Tags                : [{type : String}],
isPublic            : {type : Boolean, default : false},
Vote                : [{
    User_id         : {type : Schema.Types.ObjectId, ref : 'User'},
    Kind            : {type : Boolean}
}],
Rate                : [{
    User_id         : {type : Schema.Types.ObjectId, ref : 'User'},
    Count           : {type : Number}
}],
Comment             : [{
    User_id         : {type : Schema.Types.ObjectId, ref …

我有一个这样的收藏

[{
    "_id" : ObjectId("590c2331dc1a05e7d3525e70"),
    "name" : "Orange",
    "quarters" : {
        "first" : 20,
        "middle" : 53,
        "last" : 52
    }
}, {
    "_id" : ObjectId("590c2405dc1a05e7d3525e71"),
    "name" : "Apple",
    "quarters" : {
        "first" : 42,
        "middle" : 37,
        "last" : 16
    }
}]

我想要这样的结果

[{
    name: "Orange",
    first: 20
},{
    name: "Orange",
    middle: 53
},{
    name: "Orange",
    last: 52
},{
    name: "Apple",
    first: 42
},{
    name: "Apple",
    middle: 37
},{
    name: "Apple",
    last: 16
}]

我试图找到解决方案，但发现很少有与此问题类似的问题，但没有运气

• $unwind 聚合框架中的对象

提前致谢

我正在尝试获取数组内特定字段的总和。问题是，该数组也在另一个数组中。我的文件如下（简化）：

{
    "nome": "test-1"
    "notas": [{
        "numero_fiscal": "0001",
        "valores": {
            "portal": 1000,
            "arquivo": 1000
        },
        "abatimentos": [{
            "valor": 250,
            "tipo": "TIPO 1"
        }, {
            "valor": 250,
            "tipo": "TIPO 2"
        }]
    }, {
        "numero_fiscal": "0002",
        "valores": {
            "portal": 2000,
            "arquivo": 2000
        },
        "abatimentos": [{
            "valor": 500,
            "tipo": "TIPO 1"
        }, {
            "valor": 500,
            "tipo": "TIPO 2"
        }]
    }]
}

我希望我的输出是这样的：

{
    "_id": "resumo",
    "total_notas": 2, // this is the counter for the array "notas"
    "soma_portal": 3000, // this is the sum …

我的收藏中有以下文件。每个文档都包含有关特定位置的历史天气数据：

{
'location':'new york', 
'history':[
    {'timestamp':1524542400, 'temp':79, 'wind_speed':1, 'wind_direction':'SW'}
    {'timestamp':1524548400, 'temp':80, 'wind_speed':2, 'wind_direction':'SW'}
    {'timestamp':1524554400, 'temp':82, 'wind_speed':3, 'wind_direction':'S'}
    {'timestamp':1524560400, 'temp':78, 'wind_speed':4, 'wind_direction':'S'}
    ]
},
{
'location':'san francisco', 
'history':[
    {'timestamp':1524542400, 'temp':80, 'wind_speed':5, 'wind_direction':'SW'}
    {'timestamp':1524548400, 'temp':81, 'wind_speed':6, 'wind_direction':'SW'}
    {'timestamp':1524554400, 'temp':82, 'wind_speed':7, 'wind_direction':'S'}
    {'timestamp':1524560400, 'temp':73, 'wind_speed':8, 'wind_direction':'S'}
    ]
},
{
'location':'miami', 
'history':[
    {'timestamp':1524542400, 'temp':84, 'wind_speed':9, 'wind_direction':'SW'}
    {'timestamp':1524548400, 'temp':85, 'wind_speed':10, 'wind_direction':'SW'}
    {'timestamp':1524554400, 'temp':86, 'wind_speed':11, 'wind_direction':'S'}
    {'timestamp':1524560400, 'temp':87, 'wind_speed':12, 'wind_direction':'S'}
    ]
}

我想获取每个位置（或多或少）的最新天气数据列表，如下所示：

{
'location':'new york', 
'history':{'timestamp':1524560400, 'temp':78, 'wind_speed':4, 'wind_direction':'S'}
},
{
'location':'san francisco', 
'history':{'timestamp':1524560400, 'temp':73, …

我有 2 个集合：

用户

{
    id: 1,
    name: "Michael", 
    starred: [1, 2]
}

学校

{
    id: 1,
    name: "Uni", 
    faculties: [{
        id:1000, 
        name: "faculty1", 
        subjects: [
            {id: 1, name: "sub1"},
            {id: 2, name: "sub2"},
            {id: 3, name: "sub3"}
        ]
    }]
}

现在，在我的用户集合中，我想查找并收集每个主题对象，其 ID 在已加星标中找到。IE。starred: [1,2]包含id我想要的主题。

所以最终结果应该返回

[{id: 1, name: sub1},{id: 2, name: sub2}]

我目前正在使用 whis 聚合管道

{$match: {name: 'Michael'}},
{$unwind: "$faculties"},
{$unwind: "$faculties.subjects"},
{$lookup:
  {
     from: 'schools',
     localField: 'starred',
     foreignField: 'faculties.subjects.id',
     as: 'starredSubjects'
   }
},
{$project: …

我有一个包含 100 万个文档的集合......我已经通过了选项allowDiskUse，现在它抛出错误

TypeError: callback.apply is not a function

我已经搜索过这个，但可以得到解决方案...请帮忙

const pictures = await Picture.aggregate([
      { $sort: { createdAt: -1 }},
      { $group: {
        _id: { $dateToString: { format: "%Y-%m-%d", date: "$createdAt" } },
        pictures: {
          $push: {
            _id: '$_id',
            image: '$image',
            time: { $dateToString: { format: "%H:%M:%S", date: "$createdAt" } }
          }
        }
      }},
      { $limit: 50 },
      { $project: {
        _id: false,
        createdAt: '$_id',
        pictures: '$pictures'
      }}
    ], { allowDiskUse: true })

Mongodb 版本 - 3.6 …

我有以下查询，首先对文档进行排序，然后跳过并限制 10 条记录，以下是我的查询：

db.getCollection('jobpostings').aggregate([
{"$match":{
    "expireDate":{"$gte": ISODate("2018-08-12T00:00:00.000Z")},
    "publishDate":{"$lt": ISODate("2018-08-13T00:00:00.000Z")},
    "isPublished":true,
    "isDrafted":false,
    "deletedAt":{"$eq":null},
    "deleted":false,
    "blocked":{"$exists":false}
}},
{"$lookup":{"from":"companies","localField":"company.id","foreignField":"_id","as":"companyDetails"}},
{"$match":{"companyDetails":{"$ne":[]}}},
{"$sort":{
    "isFeatured":-1,
    "refreshes.refreshAt":-1,
    "publishDate":-1
}},
{"$skip":0},
{"$limit":10},
{"$project":{
    "position":1,"summary":1,"company":1,"publishDate":1,
    "expireDate":{"$dateToString":{"format":"%Y-%m-%d","date":"$expireDate"}},
    "locations":1,"minimumEducation":1,"workType":1,"skills":1,"contractType":1,
    "isExtensible":1,"salary":1,"gender":1,"yearsOfExperience":1,"canApplyOnline":1,"number":1,
    "isFeatured":1,"viewsCount":1,
    "status":{"$cond":{
        "if":{"$and":[
            {"$lt":["$publishDate", ISODate("2018-08-13T00:00:00.000Z")]},
            {"$gt":["$publishDate", ISODate("2018-08-11T00:00:00.000Z")]}]},"then":"New",
        "else":{"$cond":{
            "if":{"$lt":["$publishDate",ISODate("2018-08-12T00:00:00.000Z")]},"then":"Old","else":"Future"}}}},
            "companyDetails.profilePic":1,"companyDetails.businessUnits":1,"companyDetails.totalRatingAverage":1,
            "expiringDuration":{"$floor":{"$divide":[{"$subtract":["$expireDate",ISODate("2018-08-12T00:00:00.000Z")]},
            86400000]}},
            "companyDetails.totalReviews":{"$size":{"$ifNull":[{"$let":{"vars":{
                "companyDetailOne":{"$arrayElemAt":["$companyDetails",0]}},"in":"$$companyDetailOne.reviews"}},[]]}}}}

])

如果我评论跳过和限制以下是我的结果：

但以下是我的结果skip = 0, limit = 10：

现在将上述结果与以下结果进行比较skip=10, limit=10：突出显示的文档在第二页中是重复的(skip=10, limit=10)：

对于其他文档，其他页面中也存在相同的内容。