如何进行查询包括计数和集合数据

Question

示例数据

[
   { owner: '0x123124124', createdAt: '13 May 2022 at 04:20:21 UTC'},
   { owner: '0x123124124', createdAt: '13 May 2022 at 06:20:21 UTC'},
   { owner: '0x123124124', createdAt: '13 May 2022 at 03:20:21 UTC'},
   { owner: '0x123124124', createdAt: '12 May 2022 at 07:39:34 UTC'},
   { owner: '0x123124124', createdAt: '12 May 2022 at 07:39:34 UTC'},
   { owner: '0x454545627', createdAt: '11 May 2022 at 04:13:48 UTC'}
]

和我想查询这样的返回数据，

[
  { owner: '0x123124124', createdAt: '13 May 2022', count: 3},
  { owner: '0x123124124', createdAt: '13 May 2022', count: 2},
  { owner: '0x454545627', createdAt: '11 May 2022', count: 1},
]

我已经将其舍入数小时了几个小时。 感谢您的帮助。

Answer 1

1. $ set - set 创建 with

   1.1。 $ trim - 1.1.1 。

   的修剪字符串

   1.1.1。 $ arrayelemat - 从 1.1.1.1 。

   获取第一个值

   1.1.1.1。 $ split - split 创建 word“ at”。

   的字符串

2. $ group - 组成的组所有者和创建并执行计数。

3. $ project - 装饰输出文档。

db.collection.aggregate([
  {
    $set: {
      createdAt: {
        $trim: {
          input: {
            "$arrayElemAt": [
              {
                $split: [
                  "$createdAt",
                  "at"
                ]
              },
              0
            ]
          }
        }
      }
    }
  },
  {
    $group: {
      _id: {
        owner: "$owner",
        createdAt: "$createdAt"
      },
      count: {
        $sum: 1
      }
    }
  },
  {
    $project: {
      _id: 0,
      owner: "$_id.owner",
      createdAt: "$_id.createdAt",
      count: 1
    }
  }
])

示例mongo playground