使用 mongoose 在 mongoDB 中对日期进行分组和计数，仅匹配不包括时间的日期

Question

我有一个像这样的文件links

{
    "_id": "60043f2e10a0f677742b3997",
    "visit_count": 1,
    "password": null,
    "password_protected": false,
    "description": null,
    "analytics": [
        "60043fd7443aee6a585ca0d6",
        "60043563a6b1d440183a1b63"
    ],
    "alias": "m218",
    "short_url": "https://reduced.me/m218",
    "long_url": "https://test.com",
    "created_at": "2021-01-17T13:44:14.887Z",
    "updated_at": "2021-01-17T13:47:03.814Z",
    "__v": 1
}

还有另一个文档analytics 像这样

{
    "_id": "60043fd7443aee6a585ca0d6",
    "os": {
        "windows": true,
        "linux": false,
        "mac": false,
        "android": false
    },
    "browser": {
        "opera": false,
        "ie": false,
        "edge": false,
        "safari": false,
        "firefox": true,
        "chrome": false
    },
    "details": {
        "os": "Windows 10.0",
        "browser": "Firefox",
        "version": "84.0",
        "platform": "Microsoft Windows",
        "source": "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:84.0) Gecko/20100101 Firefox/84.0"
    },
    "visit_date": "2021-01-17T13:47:03.796Z"
    "__v": 0
},

{
    "_id": "60043563a6b1d440183a1b63",
    "os": {
        "windows": true,
        "linux": false,
        "mac": false,
        "android": false
    },
    "browser": {
        "opera": false,
        "ie": false,
        "edge": true,
        "safari": false,
        "firefox": false,
        "chrome": false
    },
    "details": {
        "os": "Windows 10.0",
        "browser": "Edge",
        "version": "87.0.664.75",
        "platform": "Microsoft Windows",
        "source": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.141 Safari/537.36 Edg/87.0.664.75"
    },
     "visit_date": "2021-01-17T13:02:27.663Z",
    "__v": 0
}

我正在从analytics 文档中填充links 文档中的analytics 数组。我想要实现的是从每个analytics 文档中获取visit_date 字段的对象，并仅通过day-month-year 计算与它们匹配的所有日期的数量，我不想匹配时间。

所以我正在寻找的最终输出是这样的

{
    //rest of the document fields

"visit_date": {
    "2021-01-17":2
      //and so on dates
    }

}

这里的"2021-01-17":2 来自两个analytics 文档，只有日期中的d-m-y 值匹配。其中2 是匹配日期的数量，2021-01-17 是匹配日期

任何帮助将不胜感激。

Answer 1

试试lookup with pipeline，

• $lookup 带有分析，将分析 ID 传递给 let
• $match 分析 ID 条件
• $group by visit_date, $substr 从 visit_date 获取日期
• $project 显示必填字段和 make，k(key) 和 v(value) 格式
• $addFields，使用 $arrayToObject 将 visit_date 数组转换为对象

db.links.aggregate([
  {
    $lookup: {
      from: "analytics",
      let: { analytics: "$analytics" },
      pipeline: [
        { $match: { $expr: { $in: ["$_id", "$$analytics"] } } },
        {
          $group: {
            _id: { $substr: ["$visit_date", 0, 10] },
            v: { $sum: 1 }
          }
        },
        {
          $project: {
            _id: 0,
            k: "$_id",
            v: 1
          }
        }
      ],
      as: "visit_date"
    }
  },
  { $addFields: { visit_date: { $arrayToObject: "$visit_date" } } }
])

Playground