projection:

db.persons.aggregate
([ 
{$project: {_id:0,name:1,email:1,totalage: "$dob.age",birthday: {$convert:{input:"$dob.date", to:"date"}}}},
{$project: {id:0,name:1,email:1,totalage:1,janamdin:{$dateToString: { format: “%Y-%m-%d”, date: “$birthday” }}}}
]).pretty()

Sample data

{
        "_id" : ObjectId("63cb7a5672c776ccbb47a9d1"),
        "gender" : "male",
        "name" : {
                "title" : "mr",
                "first" : "gideon",
                "last" : "van drongelen"
        },
        "location" : {
                "street" : "9982 catharijnekade",
                "city" : "vlaardingen",
                "state" : "gelderland",
                "postcode" : 65750,
                "coordinates" : {
                        "latitude" : "-86.1268",
                        "longitude" : "-54.1364"
                },
                "timezone" : {
                        "offset" : " 3:00",
                        "description" : "Baghdad, Riyadh, Moscow, St. Petersburg"
                }
        },
        "email" : "[email protected]",
        "login" : {
                "uuid" : "1ff22ccb-14e8-42ae-a762-b552f60640c9",
                "username" : "angryrabbit395",
                "password" : "gotcha",
                "salt" : "KWxOE5yb",
                "md5" : "9e4c766ad10186796fa138fa690c1029",
                "sha1" : "000f6eb6e91d2404f7cbc8b0b485a86a8c198fcd",
                "sha256" : "82286824c8d704cdcf970c488bc0f2d4c208f5ed4ae74656bbca354964576f62"
        },
        "dob" : {
                "date" : "1971-03-28T04:47:21Z",
                "age" : 47
        },
        "registered" : {
                "date" : "2004-10-20T18:02:16Z",
                "age" : 13
        },
        "phone" : "(198)-755-0721",
        "cell" : "(241)-161-7474",
        "id" : {
                "name" : "BSN",
                "value" : "66692214"
        },
        "picture" : {
                "large" : "https://randomuser.me/api/portraits/men/11.jpg",
                "medium" : "https://randomuser.me/api/portraits/med/men/11.jpg",
                "thumbnail" : "https://randomuser.me/api/portraits/thumb/men/11.jpg"
        },
        "nat" : "NL"
}


db.persons.aggregate
([ 
{$project: {_id:0,name:1,email:1,totalage: "$dob.age",birthday: {$convert:{input:"$dob.date", to:"date"}}}},
{$project: {id:0,name:1,email:1,totalage:1,janamdin:{$dateToString: { format: “%Y-%m-%d”, date: “$birthday” }}}}
]).pretty()

need just date in the year month day format

CodePudding user response：

You add some typos with your quotes and fields, try with:

db. persons.aggregate([
  {
    $project: {
      _id: 0,
      name: 1,
      email: 1,
      totalage: "$dob.age",
      birthday: {
        $convert: {
          input: "$dob.date",
          to: "date"
        }
      }
    }
  },
  {
    $project: {
      _id: 0,
      name: 1,
      email: 1,
      totalage: 1,
      janamdin: {
        $dateToString: {
          format: "%Y-%m-%d",
          date: "$birthday"
        }
      }
    }
  }
])

Link to playground