Mongodb aggregation get documents by stringdate

Question

i have list of documents like this

  "Location_id": "60b53d92ccb1483964da45f9",
    "SensorIdentifier": "CCCCCCCCCCCCCCCC",
    "SensorType": "Temperature",
    "status": true,
    "data": [
      {
        "temperature": 22.5,
        "humidite": 38.2,
        "batterie": 50,
        "time": 1623083627736,
        "date": "7-6-2021"
      },

i want to filter them by date for example i want to get documents where date between 6-6-2021 and 7-6-2021 with filtering the subdocument in data array, note that date field is string ,now here is my solution:

  {
    "$match": {
      "$expr": {
        "$and": [
          {
            "$gte": [
              "$date",
              {
                "$dateFromString": {
                  "dateString": "4-6-2021",
                  "format": "%m-%d-%Y"
                }
              }
            ]
          },
          {
            "$lte": [
              "$date",
              {
                "$dateFromString": {
                  "dateString": "7-6-2021",
                  "format": "%m-%d-%Y"
                }
              }
            ]
          }
        ]
      }
    }
  },

Answer 1

You can do it like this:

db.collection.aggregate([
  {
    "$match": {
      "Location_id": "60b53d92ccb1483964da45f9"
    }
  },
  {
    "$set": {
      "data": {
        "$filter": {
          "input": "$data",
          "cond": {
            "$and": [
              {
                "$lte": [
                  {
                    "$dateFromString": {
                      dateString: "$$this.date",
                      format: "%m-%d-%Y"
                    }
                  },
                  {
                    "$dateFromString": {
                      dateString: "7-6-2021",
                      format: "%m-%d-%Y"
                    }
                  }
                ]
              },
              {
                "$gte": [
                  {
                    "$dateFromString": {
                      dateString: "$$this.date",
                      format: "%m-%d-%Y"
                    }
                  },
                  {
                    "$dateFromString": {
                      dateString: "4-6-2021",
                      format: "%m-%d-%Y"
                    }
                  }
                ]
              }
            ]
          }
        }
      }
    }
  }
])

Here is the working example: https://mongoplayground.net/p/-l2O6wp9SFV