how to count the size if argument value is not an array

Question

I want to sort the data whose result.template array's length is greater then to others

for example object id 5808d700536d1a3d69f4cf57 has four element which mean it will be first result. but when there is no result object exists then it says the argument to $size must be an array, but was of type: missing. How to fix it please guide

 db={
  products: [
    {
      "_id": ObjectId("5808d700536d1a3d69f4cf51"),
      result: {
        "template": [
          "Mcd",
          "ded",
          "GCD"
        ]
      },
      dataB: true
    },
    {
      "_id": ObjectId("5808d700536d1a3d69f4cf53"),
      result: {
        "template": [
          "CCD",
          "GHG"
        ]
      }
    },
    {
      "_id": ObjectId("5808d700536d1a3d69f4cf56"),
      
    },
    {
      "_id": ObjectId("5808d700536d1a3d69f4cf57"),
      result: {
        "template": [
          "VVD",
          "SSD",
          "Fsd",
          "Xcd",
          
        ]
      }
    },
    {
      "_id": ObjectId("5808d700536d1a3d69f4cf43"),
      
    },
    
  ]
}

Check this https://mongoplayground.net/p/Wg144t8fvso

G2 Jakhmola · Accepted Answer · 2021-07-23 13:45:40Z

2

You can try

"count": {
        "$size": {
          "$cond": [
            {
              "$isArray": "$result.template"
            },
            "$result.template",
            []
          ]
        }
      }

https://mongoplayground.net/p/K0shGUYRMsM

answered Jul 23, 2021 at 13:45

G2 Jakhmola

8111 gold badge6 silver badges15 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

how to count the size if argument value is not an array

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related