使用 $group 对来自 mongodb 中另一个集合的 foreignField 进行分组

Question

这是我的查询：

db.getCollection('_build').aggregate([
    {
        $group:{
            _id: "$ProjectId",
            Builds: {$addToSet: "$_id"}
        }
    },
    {
        $lookup:{
            from: "_build.detail",
            localField: "Builds",
            foreignField: "BuildId",
            as: "result"
        }
    },
    {
        $project:{
            _id:0,
            ProjectId: "$_id",
            Builds: 1,
            BuildCountForProject: {$size: "$Builds"}
        }
    }

]);

查询结果：

/* 1 */
{
    "Builds" : [ 
        ObjectId("58f908411f19cf1d340974c2"), 
        ObjectId("58f902bd1f19cf1d3409749d")
    ],
    "ProjectId" : ObjectId("58f7a38f1f19cf38306a1b9c"),
    "BuildCountForProject" : 11
}

/* 2 */
{
    "Builds" : [ 
        ObjectId("58f797631091c228bc3af071"), 
        ObjectId("58f79fa31091c528bc4ff8f1"), 
        ObjectId("58f769441f19cf22dc92da24"), 
        ObjectId("58f633801f19cf4f8073b203")
    ],
    "ProjectId" : ObjectId("58e27c921091c22e34243db7"),
    "BuildCountForProject" : 4
}

我在查询结果中针对每个项目获取构建数组，我想根据每个项目中的构建查询另一个集合（使用相同的查询），想要聚合一些数据（数据必须是按 ProjectId 分组，我想加入的集合中没有 ProjectId，但正如您在结果中看到的那样，我有它在管道中）。

例子：

我想为这些构建找到不同的广告、广告集、广告系列，

1. ObjectId("58f908411f19cf1d340974c2")
2. ObjectId("58f902bd1f19cf1d3409749d")

这两个构建都属于项目 ObjectId("58f7a38f1f19cf38306a1b9c")，如结果所示。

想要输出，

{
    "ProjetId" : ObjectId("58f7a38f1f19cf38306a1b9c"),
    "BuildId" :[ ObjectId("58f908411f19cf1d340974c2"), 
                ObjectId("58f902bd1f19cf1d3409749d")]
    "UniqueAdsCount" : 10,
    "UniqueAdsetCount": 5,
    "UniqueCampaignCount": 2 
},
{
    next ProjectId,
    Builds array,
    UniqueAdsCount
    UniqueAdsetCount
    UniqueCampaignCount
},...

我想用_build.detials 加入的收藏：

{
    "_id" : ObjectId("58de834cc6e7dbe945acf890"),
    "BuildId" : ObjectId("58ef4b95c6e7dbe945ba700b"),
    "Values" : null,
    "Headers" : null,
    "Data" : {
        "Campaign Name" : "Remarketing | Remarketing | Facebook | Conversions | 03-01-2017",
        "Ad Set Name" : "Cancelled Orders_Greater than 50%-Cancelled Orders_Less than 50% | Desktop | Feed | Female | 21-65",
        "Ad Name" : "Carousel | Draw1,Excited2,Lottery5,Beach4 | S:1814082498827964 | 03-01-2017 | 70Custom Audiences | ",
        "Ad Set Run Status" : "ACTIVE",
        "Ad Status" : "ACTIVE",
        "Campaign Objective" : "Conversions",
        "Gender" : "Female",
        "Age Min" : "21",
        "Age Max" : "65",

    },
    "Status" : false,
    "CampaignName" : "Remarketing | Remarketing | Facebook | Conversions | 03-01-2017",
    "AdSetName" : "Cancelled Orders_Greater than 50%-Cancelled Orders_Less than 50% | Desktop | Feed | Female | 21-65",
    "AdName" : "Carousel | Draw1,Excited2,Lottery5,Beach4 | S:1814082498827964 | 03-01-2017 | 70Custom Audiences | ",
    "Campaign_Status" : 1,
    "Campaign_Id" : "1",
    "Adset_Status" : 1,
    "Adset_Id" : "123",
    "Ad_Status" : 1,
    "Ad_Id" : "1234"
},...

Answer 1

您可以尝试以下查询。它类似于我们这里的查询Using multiple $lookup with aggregation in mongodb。

以下查询将$lookup 转换为build details 以获取所有字段，$group 一次获取一个字段以获得不同的值，然后$project 以计算每个构建的不同值。

最后的$group 是将所有builds 推入一个数组，同时将所有构建细节的不同计数相加。

   aggregate([
      { $group: {_id: "$ProjectId",Builds: {$addToSet: "$_id"}}},
      { $lookup: {from: "_build.detail",localField: "Builds",foreignField: "BuildId",as: "result"}},
      { $unwind: "$result"},
      {
        $group: 
         {
           _id: 
            {
              ProjectId: "$_id",
              BuildId: "$result.BuildId",
              campaignName: "$result.Data.Campaign Name",
              adSet: "$result.Data.Ad Set Name"
            },
            uniqueAdNames: {$addToSet: "$result.Data.Ad Name"}
          }
      },
      { $addFields: {uniqueAdsCount: {$size: "$uniqueAdNames"}}},
      {
        $group: 
          {
            _id: 
              {
                ProjectId: "$_id.ProjectId",
                BuildId: "$_id.BuildId",
                campaignName: "$_id.campaignName"
              },
              uniqueAdsCount: {$first: "$uniqueAdsCount"},
              uniqueAdSets: {$addToSet: "$_id.adSet"}
          }
      },
      { $addFields: {uniqueAdsetCount: {$size: "$uniqueAdSets"}}},
      {
        $group: 
          {
            _id:{ProjectId: "$_id.ProjectId", BuildId: "$_id.BuildId"},
            uniqueAdsCount: {$first: "$uniqueAdsCount"},
            uniqueAdsetCount: {$first: "$uniqueAdsetCount"},
            uniqueCampaignNames: {$addToSet: "$_id.campaignName"}
          }
      },
      { $addFields: {uniqueCampaignCount: {$size: "$uniqueCampaignCount"}}},
      {
        $group: 
         {
           _id: "$projectId",
           Builds: {$push: "$_id.BuildId"},
           uniqueAdsCount: {$sum: "$uniqueAdsCount"},
           uniqueAdsetCount: {$sum: "$uniqueAdsetCount"},
           uniqueCampaignCount: {$sum: "$uniqueCampaignCount"}
          }
      },
      {
        $project:
         {
           _id: 0,
           ProjectId: "$_id.ProjectId",
           Builds: 1,
           BuildCountForProject: {$size: "$Builds"},
           uniqueAdsCount: 1,
           uniqueAdsetCount: 1,
           uniqueCampaignCount: 1,
         }
      }
   ])