如何使用MongoDB或Mongoose在一个查询中对两个集合进行分组

我有这样的页面。数据来自我的MongoDB服务器。

首先，我创建用户集合并放置这些用户数据。但是我添加了Counter集合，因为我想显示其View Count。

每个用户都有多个页面，并且“查看计数”数据是“计数器”数据的总和。

用户集合看起来像这样，我只需要登录ID（唯一）数据。

用户集合

{
    "_id": {
        "$oid": "5f7e92b88dc8f64cb4e6c2c0"
    },
    "login": "mojombo",
    "id": 1,
    "avatar_url": "https://avatars0.githubusercontent.com/u/1?v=4",
    "url": "https://api.github.com/users/mojombo",
    "html_url": "https://github.com/mojombo",
    "type": "User",
    "site_admin": "false",
    "name": "Tom Preston-Werner",
    "company": null,
    "blog": "http://tom.preston-werner.com",
    "location": "San Francisco",
    "email": "[email protected]",
    "hireable": null,
    "bio": null,
    "created_at": {
        "$date": "2007-10-20T05:24:19.000Z"
    },
    "updated_at": {
        "$date": "2020-09-22T15:50:44.000Z"
    },
    "registerDate": {
        "$date": "2020-10-08T04:16:56.459Z"
    },
    "__v": 0
}

柜台收藏

{
    "_id": {
        "$oid": "5f8e5bde9054ba2477dc2c57"
    },
    "repoName": "ale",
    "repoNumber": 171780764,
    "userName": "technicalpickles",
    "userNumber": 159,
    "viewDate": "2020-10-20",
    "count": 1
}

在“计数器”集合中，我仅需要userName，count字段来计算计数器数据。

所以我尝试使用循环和聚合方法，但问题是用户数据太多，因此我不得不向服务器发送太多查询。（如果我有10000个用户数据，则必须发送10000个请求）因此，我一定不能使用for循环方法。

router.get(`/sitemap/0`, async (req, res, next) => {
  let name;
  let dataArray = [];
  let pageNumber = (Number(req.params.page) * 10000); // Current Page Number
  let nextPage = (Number(req.params.page) + 1) * 10000; // Next Page Number
  let pageResult; // Page Result
  try {
    let users = await User.find({}, 'login id').limit(1000)
    for (let i = 0; i < 1000; i++) {
      name = users[i].login
      let counters = await Counter.aggregate([{
          $match: {
            id: users.id,
            userName: users[i].login
          }
        },
        {
          $group: {
            _id: `${users[i].login}`,
            count: {
              $sum: "$count"
            }
          }
        }
      ])
      dataArray.push(counters)
      console.log(counters)
    }
    console.log(dataArray)

  } catch (e) {
    // throw an error
    throw e;
  }
  res.render("sitemap", {
    dataArray
  })
});

代码结果

因此，我想发送单个查询，我认为应该使用“聚合”方法。但是没有“ for循环”。

我想加入Users collection，Counters collection但听说MongoDB和Mongoose中没有加入功能。

我只想要这样的结果。反正有这样的办法吗？

{
    "_id": {
        "$oid": "5f7e92b88dc8f64cb4e6c2c0"
    },
    "login": "mojombo", --------------Match login with counter collection 'userName' value
    "id": 1,  ------------------------Match id with counter collection 'id' value
    "count": [Sum of counters count data and it should be Number] ------- Only this field is added
    "avatar_url": "https://avatars0.githubusercontent.com/u/1?v=4",
    "url": "https://api.github.com/users/mojombo",
    "html_url": "https://github.com/mojombo",
    "type": "User",
    "site_admin": "false",
    "name": "Tom Preston-Werner",
    "company": null,
    "blog": "http://tom.preston-werner.com",
    "location": "San Francisco",
    "email": "[email protected]",
    "hireable": null,
    "bio": null,
    "created_at": {
        "$date": "2007-10-20T05:24:19.000Z"
    },
    "updated_at": {
        "$date": "2020-09-22T15:50:44.000Z"
    },
    "registerDate": {
        "$date": "2020-10-08T04:16:56.459Z"
    },
    "__v": 0
}