I have a collection where from the backend user can input multiple same name bikes but with different registration number but in front-End I want them to be grouped by matching the same name but as user updates separately display image changes but I want only one display image as it is 1 vehicle

provided there is a node created I will implement it we can sort it by the latest and take the price and image of it

1. Activa -2 Count
2. KTM -1 Count

but there is a catch.

Activa 2 bikes but I want only count 2 and the price as it is the same in an array I want only 1 and the same applies to displayimage here display image file path is different but I want the latest one only Sharing data below

Data:

[
    {
        "price": [
            {
                "Description": "Hourly",
                "Price": "1"
            },
            {
                "Description": "Daily",
                "Price": "11"
            },
            {
                "Description": "Monthly",
                "Price": "111"
            }
        ],
        "_id": "62e69ee3edfe4d0f3cb4994a",
        "bikename": "KTM",
        "bikenumber": "KA05HM2034",
        "bikebrand": {
            "id": 1,
            "label": "Honda"
        },
        "freekm": 234,
        "displayimage": {
            "file": "bike-2020-honda-city-exterior-8-1659281111883.jpg",
            "file_path": "https://www.example.com/images/upload/bike-2020-honda-city-exterior-8-1659281111883.jpg",
            "idx": 1
        }
    },
    {
        "price": [
            {
                "Description": "Hourly",
                "Price": "1"
            },
            {
                "Description": "Daily",
                "Price": "11"
            },
            {
                "Description": "Monthly",
                "Price": "111"
            }
        ],
        "_id": "62dba8418ef8f51f454ed757", 
        "bikename": "Activa",
        "bikenumber": "KA05HM2033",
        "bikebrand": {
            "id": 1,
            "label": "Honda"
        }, 
        "freekm": 234, 
        "displayimage": {
            "file": "bike-v_activa-i-deluxe-1658562557459.jpg",
            "file_path": "https://www.example.com/images/upload/bike-v_activa-i-deluxe-1658562557459.jpg",
            "idx": 0
        }
    },
    {
        "price": [
            {
                "Description": "Hourly",
                "Price": "1"
            },
            {
                "Description": "Daily",
                "Price": "11"
            },
            {
                "Description": "Monthly",
                "Price": "111"
            }
        ],
        "_id": "62d7ff7e70b9ab38c6ab0cb1", 
        "bikename": "Activa",
        "bikenumber": "KA05HM2223",
        "bikebrand": {
            "id": 1,
            "label": "Honda"
        }, 
        "freekm": 234,
        "afterfreekmprice": 22,
        "descreption": "Activa",
        "displayimage": {
            "file": "bike-v_activa-i-deluxe-1658322798414.jpg",
            "file_path": "https://www.example.com/images/upload/bike-v_activa-i-deluxe-1658322798414.jpg",
            "idx": 0
        }
    }
]

Expected:

[
    {
        "_id":{
            "price": [
                {
                    "Description": "Hourly",
                    "Price": "1"
                },
                {
                    "Description": "Daily",
                    "Price": "11"
                },
                {
                    "Description": "Monthly",
                    "Price": "111"
                }
            ],
            "_id": "62dba8418ef8f51f454ed757", 
            "bikename": "Activa",
            "bikebrand": {
                "id": 1,
                "label": "Honda"
            }, 
            "freekm": 234, 
            "displayimage": {
                "file": "bike-v_activa-i-deluxe-1658562557459.jpg",
                "file_path": "https://www.example.com/images/upload/bike-v_activa-i-deluxe-1658562557459.jpg",
                "idx": 0
            }
        },
        "count": 2
    },
    {
        "_id":{
            "price": [
                {
                    "Description": "Hourly",
                    "Price": "1"
                },
                {
                    "Description": "Daily",
                    "Price": "11"
                },
                {
                    "Description": "Monthly",
                    "Price": "111"
                }
            ],
            "_id": "62e69ee3edfe4d0f3cb4994a",
            "bikename": "KTM",
            "bikebrand": {
                "id": 1,
                "label": "Honda"
            },
            "freekm": 234,
            "displayimage": {
                "file": "bike-2020-honda-city-exterior-8-1659281111883.jpg",
                "file_path": "https://www.example.com/images/upload/bike-2020-honda-city-exterior-8-1659281111883.jpg",
                "idx": 1
            }
        }
        "count": 1
    }
] 

CodePudding user response：

You can use $group for this:

db.collection.aggregate([
  {$group: {
      _id: "$bikename",
      count: {$sum: 1},
      data: {$first: "$$ROOT"}
    }
  },
  {$set: {"data.count": "$count"}},
  {$replaceRoot: {newRoot: "$data"}}
])

See how it works on the playground example

CodePudding user response：

You can use the aggregation pipeline,

• $sort by _id in descending order
• $group by bikename and get the first root document that is latest one in root and count total documents in count
• $project to show required documents

db.collection.aggregate([
  { $sort: { _id: -1 } },
  {
    $group: {
      _id: "$bikename",
      root: { $first: "$$ROOT" },
      count: { $sum: 1 }
    }
  },
  {
    $project: {
      _id: "$root",
      count: 1
    }
  }
])

Playground