在内部MongoDB中查找或查找每个

Question

Let's say I have two collection in my database call rumahsakit .

First collection called dim_dokter :

[{
    "_id": ObjectId("58b22c79e8c1c52bf3fad997"),
    "nama_dokter": "Dr. Basuki Hamzah",
    "spesialisasi": "Spesialis Farmakologi Klinik",
    "alamat": " Jalan Lingkar Ring Road Utara, Yogyakarta "
}, {
    "_id": ObjectId("58b22c79e8c1c52bf3fad998"),
    "nama_dokter": "Dr. Danie Nukman",
    "spesialisasi": "Spesialis Anak",
    "alamat": " Jalan Sudirman, Yogyakarta "
}, {
    "_id": ObjectId("58b22c79e8c1c52bf3fad999"),
    "nama_dokter": "Dr. Bambang Kurnia",
    "spesialisasi": "Spesialis Mikrobiologi Klinik",
    "alamat": " Jalan Ahmad Yani, Yogyakarta "
}]

Second collection called fact_perawatan :

[{
    "_id": ObjectId("58b22d13e8c1c52bf3fad99a"),
    "nama_pasien": "Clark",
    "detail_perawatan": [{
        "id_dokter": ObjectId("58b22c79e8c1c52bf3fad997"),
        "jumlah_obat": 1
    }, {
        "id_dokter": ObjectId("58b22c79e8c1c52bf3fad998"),
        "jumlah_obat": 1
    }]
}]

Collection fact_perawatan have the id_dokter that is actually point to the dim_dokter._id . I want to do aggregation to show this data in fact_perawatan collection but instead showing just the id_dokter , I want to use nama_dokter from dim_dokter .

This is my code so far:

db.fact_perawatan.aggregate([
   {
       $match:
         {
           '_id': db.fact_perawatan.find({"_id" : ObjectId("58b22d13e8c1c52bf3fad99a")})[0]._id
       }
   },
   {
      $project:
         {
            nama_pasien: db.fact_perawatan.find({"_id": ObjectId("58b22d13e8c1c52bf3fad99a")})[0].nama_pasien,
            perawatan: [
              {
                dokter: db.dim_dokter.find({"_id" : db.fact_perawatan.find({"_id": ObjectId("58b22d13e8c1c52bf3fad99a")})[0].detail_perawatan[0].id_dokter})[0].nama_dokter,

              },
            ]  
          }
   }
])

result:

{ "_id" : ObjectId("58b22d13e8c1c52bf3fad99a"), "nama_pasien" : "Clark", "perawatan" : [ { "dokter" : "Dr. Basuki Hamzah" } ] }

Those code can get the nama_dokter from dim_dokter , but only one data. In my case, the data can be up to 5. do the detail_perawatan[0] to [5] is not solution.

So, this code:

db.dim_dokter.find({"_id" : db.fact_perawatan.find({"_id": ObjectId("58b22d13e8c1c52bf3fad99a")})[0].detail_perawatan[0].id_dokter})[0].nama_dokter,

How make the code above to loop as many as the data in there ? so I can get all the data.

Thanks

Answer 1

You can use a $lookup to left join with dim_dokter following by a $group to regroup your data in perawatan field :

db.fact_perawatan.aggregate([{
    $match: {
        '_id': ObjectId("58b22d13e8c1c52bf3fad99a")
    }
}, {
    $unwind: "$detail_perawatan"
}, {
    $lookup: {
        from: "dim_dokter",
        localField: "detail_perawatan.id_dokter",
        foreignField: "_id",
        as: "dim_dokter"
    }
}, {
    $unwind: "$dim_dokter"
}, {
    $group: {
        _id: "$_id",
        nama_pasien: {
            $first: "$nama_pasien"
        },
        perawatan: {
            $push: {
                "dokter": "$dim_dokter.nama_dokter"
            }
        }
    }
}])

The $unwind is used to deconstruct the array field detail_perawatan to be able to $lookup afterwards