I want to find information that is on the same date in MongoDB

Question

I want to find information that is on the same date.My Data is

[
  {
    "reservations": [],
    "_id": "5ff62f01d274650f5f187c00",
    "floorNumber": "floor 4",
    "sessionInDay": "morning",
    "start": "2021-01-10T00:00:00.000Z",
    "seatsAvailable": 15,
    "id": 1,
    "__v": 0
  },
  {
    "reservations": [],
    "_id": "5ff6346be9a69310deeeabc2",
    "floorNumber": "floor 4",
    "sessionInDay": "morning",
    "start": "2021-01-05T00:00:00.000Z",
    "seatsAvailable": 15,
    "id": 2,
    "__v": 0
  },
  {
    "reservations": [],
    "_id": "5ff6346be9a69310deeeabc2",
    "floorNumber": "floor 4",
    "sessionInDay": "afternoon",
    "start": "2021-01-05T00:00:00.000Z",
    "seatsAvailable": 15,
    "id": 3,
    "__v": 0
  }
]

I want to combine data with the same start date. To come out in what format? How do I query? The data format I want to output :

[
  {
    "start": "2021-01-10T00:00:00.000Z",
    "details": [
      {
        "reservations": [],
        "_id": "5ff62f01d274650f5f187c00",
        "floorNumber": "floor 4",
        "sessionInDay": "morning",
        "start": "2021-01-10T00:00:00.000Z",
        "seatsAvailable": 15,
        "id": 1
      }
    ]
  },
  {
    "start": "2021-01-05T00:00:00.000Z",
    "details": [
      {
        "reservations": [],
        "_id": "5ff6346be9a69310fad23413",
        "floorNumber": "floor 4",
        "sessionInDay": "morning",
        "start": "2021-01-05T00:00:00.000Z",
        "seatsAvailable": 15,
        "id": 2
      },
      {
        "reservations": [],
        "_id": "5ff6346be9a69310deeeabc2",
        "floorNumber": "floor 4",
        "sessionInDay": "afternoon",
        "start": "2021-01-05T00:00:00.000Z",
        "seatsAvailable": 15,
        "id": 3
      }
    ]
  }
]

The last question, this step. Should I format data like this, save it to the Database, or should I use the Query method?

Thank to help me.

i think this can help you https://stackoverflow.com/questions/5825520/in-mongoose-how-do-i-sort-by-date-node-js — Chamsddine Bouzaine, Jan 09 '21 at 21:18

score 1 · Accepted Answer · edited Jan 10 '21 at 05:44

Finding all documents on same date ( example for 2021-01-10 ):

db.reservations.find({start:/^2021-01-10/})

Combine data for the same start date:

db.reservations.aggregate([ 
  {$project:{date:{$substr:["$start",0,10]}, floorNumber:1,sessionDay:1,start:1,seatsAvailable:1 , id:1,"__v":1 ,_id:0 }} ,
  {$group:{_id:"$date" , details:{$push:"$$ROOT"}   }} , 
  {$project:{date:"$_id", _id:0 ,details:1} } 
])

On the question if you need to format the data like in the aggregation result , it very depends on how you use the data , best in mongodb is to denormalize as much as possible and to have the data together in natural way same way as it will be shown , so if in 90% of the time you will query by date and show all reservations per day most of the time it maybe better to modify as in the aggregation result...

I assume the `start` values are actually `Date` objects, so proper query would be `{start: ISODate("2021-01-10T00:00:00Z")}` — Wernfried Domscheit, Jan 10 '21 at 13:58
Instead of `$project` you can also use `$set` (or the alias `$addFields`). This preserve existing fields and you don't have to list all of them. — Wernfried Domscheit, Jan 10 '21 at 14:00

I want to find information that is on the same date in MongoDB

1 Answers1