Tukukkk

I am new to MongoDB. I have the following collection : CallLeg which contains the data in the following format

{

    "_id" : ObjectId("5bf5504a937eb609c4d020e4"),

    "startedAt" : ISODate("2018-11-21T17:50:45.909Z"),

    "endedAt" : ISODate("2018-11-21T18:02:09.909Z"),

    "cc" : "91",

    "phone" : "1234567890",

    "type" : "pstn",

    "status" : true,

    "channel" : "mF4YnGi7SM4qCeKHJ6SYunqkano2BNQQ",

    "cost" : 0,

    "duration" : 0,

    "cid" : "ABCDEFGH"



}

{

    "_id" : ObjectId("5bf5504a937eb609c4d020e5"),

    "startedAt" : ISODate("2018-11-21T17:50:10.110Z"),

    "endedAt" : ISODate("2018-11-21T18:02:10.110Z"),

    "cc" : "91",

    "phone" : "0007654321",

    "type" : "voip",

    "status" : true,

    "channel" : "mF4YnGi7SM4qCeKHJ6SYunqkano2BNQQ",

    "cost" : 0,

    "duration" : 0,

    "cid" : "ABCDEFGH"



}

I want to get the output as follows :

• If cid is same for 'n' objects, it should return those objects. Let's say it returns 2


• Then if obj1 has type=pstn and obj2 has type=voip it should return answer as MIXED, if obj1_type = obj2_type = voip it should return VOIP and similar for pstn for the same cid.

Hope I am clear with my question.

You can use below aggregation:

db.CallLeg.aggregate([

    {

        $group: {

            _id: "$cid",

            objects: { $push: "$$ROOT" }

        }

    },

    {

        $match: { objects: { $size: 2 } }

    },

    {

        $addFields: {

            answer: {

                $switch: {

                    branches: [

                        { case: { $allElementsTrue: [ 

                            { $map: { input: "$objects", as: "o", in: { $eq: [ "$$o.type", "voip" ] } } } ] } , then: "voip" },

                        { case: { $allElementsTrue: [ 

                            { $map: { input: "$objects", as: "o", in: { $eq: [ "$$o.type", "pstn" ] } } } ] } , then: "pstn" },

                    ],

                    default: "MIXED"

                }

            }

        }

    }

])

Basically you need to $group by cid to compare multiple documents with each other. You can also add $match before $group if you need to analyze only one cid. Then you can use $size to check the number of "same" objects. In the last stage you need to compare the elements in objects array. You can use $map to get an array of boolean values which will indicate how many voip and pstns values you have. Then you need $allElementsTrue to check if you have one type for all items. Everything can be placed inside $switch to define last, default branch which is MIXED