collection.findOne соответствует запросу во всей коллекции, в то время как мне нужно найти его в массиве объектов

Question

Я столкнулся со сценарием, в котором мне нужно сохранить данные в mongoDB, но сначала мне нужно проверить, присутствуют ли данные в массиве объектов . Я пытался использовать collection.findOne () . Это метод поиска во всей коллекции. Мне нужно, чтобы он соответствовал в документе-> массив объектов-> массив объектов , вот в данном случае farm [] -> device [] . т. е. найдите в этой ферме аналогичное имя устройства. Есть ли другой способ сделать это?

Внутренний код

  User.findOne({ 'farm.device.deviceName':deviceName }).then(device => {
    if (device) {
      return res.status(400).json({ "Device Name " :  "Device already exists."});
    } else {
...saving part

Моя примерная схема

[
  {
    "_id": "5d3ac84a86688123789e13b2",
    "name": "Puja",
    "email": "puja@gmail.com",
    "password": "$2a$10$r17zOU1gTJvwoB.nBdRvi.qvDmsJhIlHbp//s8l0KEKgCEvbKoZAu",
    "location": "Delhi",
    "createdDate": "2019-07-26T09:30:50.243Z",
    "farm": [
      {
        "location": [
          "11.33,22.99"
        ],
        "_id": "5d3ff9d68e34cb265c030819",
        "farmName": "Xyz",
        "description": "Testing that info is  saved ",
        "farmAddDate": "2019-07-30T08:03:34.247Z",
        "device": [
          {
            "_id": "5d402def7cef9f20c8272fc4",
            "deviceName": " DeviceX01",
            "deviceType": " Test",
            "description": " This is a test",
            "deviceLocation": "11.22,33.12",
            "Parameter": " temp",
            "Topic": "v1/ DeviceX01/11.22,33.12/ temp"
          }
        ]
      },
      {
        "location": [],
        "_id": "5d42d171e7ceef2a90245470",
        "farmName": "Xilo",
        "description": "This is test from Postman Api Request",
        "farmAddDate": "2019-08-01T11:48:01.883Z",
        "device": [
          {
            "_id": "5d441878f1877637cc712d07",
            "deviceName": "Xki",
            "deviceType": "Muc",
            "description": "This is test for updation of specific data in a specfic farm .Test Pass",
            "deviceLocation": [
              "11",
              "180"
            ],
            "Parameter": "Hello Happy",
            "Topic": "v1/Xki/11,180/Hello Happy"
          },
          {
            "_id": "5d4418953968370e64c32e1f",
            "deviceName": "Xki",
            "deviceType": "Muc",
            "description": "This is test for updation of specific data in a specfic farm .Test Pass",
            "deviceLocation": [
              "11",
              "180"
            ],
            "Parameter": "Hello Happy",
            "Topic": "v1/Xki/11,180/Hello Happy"
          },
          {
            "_id": "5d4425548b3cf92af46e2c9a",
            "deviceName": "Xki",
            "deviceType": "Muc",
            "description": "This is test for updation of specific data in a specfic farm .Test Pass",
            "deviceLocation": [
              "11",
              "180"
            ],
            "Parameter": "Hello Happy 1",
            "Topic": "sagita/5d42d171e7ceef2a90245470/Xki/11,180/Hello Happy 1"
          },
          {
            "_id": "5d44256d8b3cf92af46e2c9b",
            "deviceName": " DeviceX01",
            "deviceType": " Test",
            "description": " This is a test",
            "deviceLocation": "11.22,33.12",
            "Parameter": " set",
            "Topic": "sagita/5d42d171e7ceef2a90245470/ DeviceX01/11.22,33.12/ set",
            "DeviceJson": [
              "{ \"$schema\": \"http: //json-schema.org/draft-04/schema#\", \"type\": \"object\", \"properties\": { \"_id\": { \"type\": \"ObjectId\" }, \"name\": { \"type\": \"string\" }, \"email\": { \"type\": \"string\" }, \"password\": { \"type\": \"string\" }, \"location\": { \"type\": \"string\" }, \"createdDate\": { \"type\": \"Date\" }, \"farm\": { \"type\": \"array\", \"items\": [ { \"type\": \"object\", \"properties\": { \"location\": { \"type\": \"array\", \"items\": [ { \"type\": \"string\" } ] }, \"_id\": { \"type\": \"ObjectId\" }, \"farmName\": { \"type\": \"string\" }, \"description\": { \"type\": \"string\" }, \"farmAddDate\": { \"type\": \"Date\" }, \"device\": { \"type\": \"array\", \"items\": [ { \"type\": \"object\", \"properties\": { \"_id\": { \"type\": \"ObjectId\" }, \"deviceName\": { \"type\": \"string\" }, \"deviceType\": { \"type\": \"string\" }, \"description\": { \"type\": \"string\" }, \"deviceLocation\": { \"type\": \"string\" }, \"Parameter\": { \"type\": \"string\" }, \"Topic\": { \"type\": \"string\" } }, \"required\": [ \"_id\", \"deviceName\", \"deviceType\", \"description\", \"deviceLocation\", \"Parameter\", \"Topic\" ] } ] } }, \"required\": [ \"location\", \"_id\", \"farmName\", \"description\", \"farmAddDate\", \"device\" ] }, { \"type\": \"object\", \"properties\": { \"location\": { \"type\": \"array\", \"items\": {} }, \"_id\": { \"type\": \"ObjectId\" }, \"farmName\": { \"type\": \"string\" }, \"description\": { \"type\": \"string\" }, \"farmAddDate\": { \"type\": \"Date\" }, \"device\": { \"type\": \"array\", \"items\": [ { \"type\": \"object\", \"properties\": { \"_id\": { \"type\": \"ObjectId\" }, \"deviceName\": { \"type\": \"string\" }, \"deviceType\": { \"type\": \"string\" }, \"description\": { \"type\": \"string\" }, \"deviceLocation\": { \"type\": \"array\", \"items\": [ { \"type\": \"string\" }, { \"type\": \"string\" } ] }, \"Parameter\": { \"type\": \"string\" }, \"Topic\": { \"type\": \"string\" } }, \"required\": [ \"_id\", \"deviceName\", \"deviceType\", \"description\", \"deviceLocation\", \"Parameter\", \"Topic\" ] }, { \"type\": \"object\", \"properties\": { \"_id\": { \"type\": \"ObejctId\" }, \"deviceName\": { \"type\": \"string\" }, \"deviceType\": { \"type\": \"string\" }, \"description\": { \"type\": \"string\" }, \"deviceLocation\": { \"type\": \"array\", \"items\": [ { \"type\": \"string\" }, { \"type\": \"string\" } ] }, \"Parameter\": { \"type\": \"string\" }, \"Topic\": { \"type\": \"string\" } }, \"required\": [ \"_id\", \"deviceName\", \"deviceType\", \"description\", \"deviceLocation\", \"Parameter\", \"Topic\" ] }, { \"type\": \"object\", \"properties\": { \"_id\": { \"type\": \"ObjectId\" }, \"deviceName\": { \"type\": \"string\" }, \"deviceType\": { \"type\": \"string\" }, \"description\": { \"type\": \"string\" }, \"deviceLocation\": { \"type\": \"array\", \"items\": [ { \"type\": \"string\" }, { \"type\": \"string\" } ] }, \"Parameter\": { \"type\": \"string\" }, \"Topic\": { \"type\": \"string\" } }, \"required\": [ \"_id\", \"deviceName\", \"deviceType\", \"description\", \"deviceLocation\", \"Parameter\", \"Topic\" ] }, { \"type\": \"object\", \"properties\": { \"_id\": { \"type\": \"ObjectId\" }, \"deviceName\": { \"type\": \"string\" }, \"deviceType\": { \"type\": \"string\" }, \"description\": { \"type\": \"string\" }, \"deviceLocation\": { \"type\": \"string\" }, \"Parameter\": { \"type\": \"string\" }, \"Topic\": { \"type\": \"string\" }, \"DeviceJson\": { \"type\": \"array\", \"items\": [ { \"type\": \"string\" } ] } }, \"required\": [ \"_id\", \"deviceName\", \"deviceType\", \"description\", \"deviceLocation\", \"Parameter\", \"Topic\", \"DeviceJson\" ] } ] } }, \"required\": [ \"location\", \"_id\", \"farmName\", \"description\", \"farmAddDate\", \"device\" ] }, { \"type\": \"object\", \"properties\": { \"location\": { \"type\": \"array\", \"items\": [ { \"type\": \"string\" } ] }, \"_id\": { \"type\": \"ObjectId\" }, \"farmName\": { \"type\": \"string\" }, \"description\": { \"type\": \"string\" }, \"farmAddDate\": { \"type\": \"Date\" }, \"device\": { \"type\": \"array\", \"items\": [ { \"type\": \"object\", \"properties\": { \"_id\": { \"type\": \"ObjectId\" }, \"deviceName\": { \"type\": \"string\" }, \"deviceType\": { \"type\": \"string\" }, \"description\": { \"type\": \"string\" }, \"deviceLocation\": { \"type\": \"array\", \"items\": [ { \"type\": \"string\" }, { \"type\": \"string\" } ] }, \"Parameter\": { \"type\": \"string\" }, \"Topic\": { \"type\": \"string\" } }, \"required\": [ \"_id\", \"deviceName\", \"deviceType\", \"description\", \"deviceLocation\", \"Parameter\", \"Topic\" ] } ] } }, \"required\": [ \"location\", \"_id\", \"farmName\", \"description\", \"farmAddDate\", \"device\" ] } ] }, \"__v\": { \"type\": \"integer\" }, \"farmModifyDate\": { \"type\": \"Timestamp\" }, \"lastModified\": { \"type\": \"Timestamp\" }, \"deviceModifyDate\": { \"type\": \"Timestamp\" }, \"deviceModified\": { \"type\": \"Timestamp\" } }, \"required\": [ \"_id\", \"name\", \"email\", \"password\", \"location\", \"createdDate\", \"farm\", \"__v\", \"farmModifyDate\", \"lastModified\", \"deviceModifyDate\", \"deviceModified\" ] }"
            ]
          }
        ]
      },
      {
        "location": [
          "11.22,65.33"
        ],
        "_id": "5d492a4a1294110f64196b2d",
        "farmName": "Durgapur",
        "description": "This is a test for frontend to backend",
        "farmAddDate": "2019-08-06T07:20:42.654Z",
        "device": [
          {
            "_id": "5d4bd62900b433276c2845af",
            "deviceName": "Farm @2 Device 001",
            "deviceType": "Intel Edision",
            "description": "This is a test for creation of Data Bucket of Topic",
            "deviceLocation": [
              "12.33",
              "56.33"
            ],
            "Parameter": "Temperature",
            "Topic": "sagita/model/5d492a4a1294110f64196b2d/Farm @2 Device 001/12.33,56.33/Temperature"
          }
        ]
      }
    ],
    "__v": 0,
    "lastModified": "2019-12-04T06:59:17.431Z",
    "farmModifyDate": "6764284414131175425",
    "deviceModifyDate": "6720517743902195713",
    "deviceModified": "6766475118035075073"
  }
]

Answer 1

Вы можете сделать запрос более точным c - например, совпадение по userId - чтобы ограничить поиск всегда проверкой 1 указанного c документа.

Если вы хотите ограничить его Кроме указанной фермы c, вы можете оформить заказ на $ elemMatch - это может помочь сопоставить по 2 условиям в указанной ферме c.