mongodb inner object to parent level-CodePudding

I got result after aggregate like

{data: [{"_id":"61922aed85c74b2d1ef671bb","employee":{"firstName":"fname","lastName":"lname","middleName":"mname"},"days":[{"_id":"61922aed85c74b2d1ef671be","day":"2021-09-01T21:00:00.000Z","data":{"hours":0,"type":"OT","_id":"61922aed85c74b2d1ef671bf","updateDate":"2021-11-15T09:39:57.624Z"}},{"_id":"61922aed85c74b2d1ef671c0","day":"2021-09-02T21:00:00.000Z","data":{"hours":0,"type":"OT","_id":"61922aed85c74b2d1ef671c1","updateDate":"2021-11-15T09:39:57.625Z"}}]}]}

Is it possible extract inner object of data of days array to the parent level.

From this {"_id":"61922aed85c74b2d1ef671be","day":"2021-09-01T21:00:00.000Z","data":{"hours":0,"type":"OT","_id":"61922aed85c74b2d1ef671bf","updateDate":"2021-11-15T09:39:57.624Z"}}

to this

{"_id":"61922aed85c74b2d1ef671be","day":"2021-09-01T21:00:00.000Z", "hours":0,"type":"OT", "updateDate":"2021-11-15T09:39:57.624Z"}

CodePudding user response：

Simply use $project like this:

db.collection.aggregate([
  {
    "$project": {
      "day": 1,
      "hours": "$data.hours",
      "type": "$data.type",
      "updateDate": "$data.updateDate"
    }
  }
])

Example here

Or to update values inside the array:

db.collection.aggregate([
  {
    "$project": {
      "_id": 1,
      "employee": 1,
      "days": {
        "$map": {
          "input": "$days",
          "as": "d",
          "in": {
            "_id": "$$d._id",
            "day": "$$d.day",
            "hours": "$$d.data.hours",
            "type": "$$d.data.type",
            "updateData": "$$d.data.updateDate"
          }
        }
      }
    }
  }
])

Example here