CODEWITHSUNDEEP
mongodbaggregation-framework
Alexander Phung
Alexander Phung

Reputation: 105

$geoNear for a list embeded locations and return distance for all location in list

I have an user collection:


{
    "name": "David",
    "age": 20,
    "addresses": [
        {
            "radius": 10000,
            "location": {
                "type": "Point",
                "coordinates": [106.785299, 20.999999]
            }
        },
        {
            "radius": 30000,
            "location": {
                "type": "Point",
                "coordinates": [105.785299, 20.979733]
            }
        }
    ]
}

Each user will have one or more address. I want to calculate the distance between these addresses with a point, then using calculated distance to compare with radius of each address. If distance < radius then keep address else remove address from addresses list. I am using below query:


db.collection.aggregrate(
    {
        "$geoNear": {
            "near": {"type": "Point", "coordinates": [ 105.823620, 21.006047 ]},
            "distanceField": "distance",
            "key": "addresses.location"
        }
    }
)

But this query only return the distance of nearest address, like this:


{
    "name": "David",
    "age": 20,
    "addresses": [
        {
            "radius": 10000,
            "location": {
                "type": "Point",
                "coordinates": [105.785299, 20.979733]
            }
        },
        {
            "radius": 30000,
            "location": {
                "type": "Point",
                "coordinates": [105.785299, 20.979733]
            }
        }
    ],
    "distance": 110000 // <--- distance is added here, just for nearest addrest
}

My expected result:


{
    "name": "David",
    "age": 20,
    "addresses": [
        {
            "radius": 10000,
            "location": {
                "type": "Point",
                "coordinates": [105.785299, 20.979733]
            },
            "distance": 2000``// <------ add distance here for each addesss`
        },
        {
            "radius": 30000,
            "location": {
                "type": "Point",
                "coordinates": [105.785299, 20.979733]
            },
            "distance": 30000 // <------ add distance here for each addesss
        }
    ]
}

So next stage I can compare distance with radius and keep proper adddress Anybody know how to do it ? thanks

Upvotes: 1

Views: 153

Answers (1)

Valijon
Valijon

Reputation: 13103

You need to store each address in an individual document:

{
    "_id" : ObjectId("5ec77d127df107cd889d567d"),
    "name" : "David",
    "age" : 20,
    "addresses" : {
        "radius" : 10000,
        "location" : {
            "type" : "Point",
            "coordinates" : [ 
                105.785299, 
                20.979733
            ]
        }
    }
},
{
    "_id" : ObjectId("5ec77f7843732e8f9a63bf67"),
    "name" : "David",
    "age" : 20,
    "addresses" : {
        "radius" : 30000,
        "location" : {
            "type" : "Point",
            "coordinates" : [ 
                105.795299, 
                20.989733
            ]
        }
    }
}

Now, we perform $geoNear and $group stages:

db.user.aggregate([
  {
    "$geoNear": {
      "near": {
        "type": "Point",
        "coordinates": [
          105.823620,
          21.006047
        ]
      },
      "distanceField": "distance",
      "key": "addresses.location"
    }
  },
  {
    "$group": {
      "_id": "$name",
      "name": {
        "$first": "$name"
      },
      "age": {
        "$first": "$age"
      },
      "addresses": {
        "$push": {
          "$mergeObjects": [
            "$addresses",
            {
              "distance": "$distance"
            }
          ]
        }
      }
    }
  }
])

Upvotes: 1

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