joining collections sub-subdocument with other collections subdocument using aggregate mongodb mongoose - mongodb

Question

So, I have this kind of model
const produkSchema = new mongoose.Schema({
nama_produk: String,
etalase: {type: mongoose.Schema.Types.ObjectID, ref: 'kategori'},
kategori: {type: mongoose.Schema.Types.ObjectID, ref: 'kategori'},
jenis: {type: mongoose.Schema.Types.ObjectID, ref: 'kategori.jenis'},
bahan: String,
warna: String,
deskripsi: String,
foto_produk: [String],
harga: Number,
link_bukalapak: String,
link_shopee: String,
link_tokopedia: String,
}, {
weights: {
nama_produk: 5,
},
timestamps: true
})
const tokoSchema = new mongoose.Schema({
username: {type: String, trim: true},
password: {type: String, required: true, select: false},
merek: String,
listMerek: [{type: mongoose.Schema.Types.ObjectID, ref: 'produk'}],
deskripsi: String,
follower: [{type: mongoose.Schema.Types.ObjectID, ref: 'user'}],
email: {type: String, trim: true, unique: true},
instagram: String,
whatsapp: String,
website: String,
alamat: String,
foto_profil: String,
bukalapak: String,
shopee: String,
tokopedia: String,
fotoktp: String,
banner: [{
gambar: {type: String, required: true, trim: true},
order: {type: Number, required: true},
}],
produk: [produkSchema],
etalase: [{type: mongoose.Schema.Types.ObjectID, ref: 'kategori'}],
approve: {type: Number, default: 0}, // 0: pending, 1: reject, 2: approve
populer: {type: Boolean, default: false},
}, {timestamps: true});
exports.toko = mongoose.model("toko", tokoSchema);
const jenisSchema = new mongoose.Schema({
label: String,
gambar: String,
}, {timestamps: true})
const kategoriSchema = new mongoose.Schema({
label: String,
gambar: String,
jenis: [jenisSchema]
}, {timestamps: true});
so what I want to join is, toko.produk.jenis with kategori.jenis, but as you know, mongoose can't populate between subdocument, I have tried toko.find().populate("produk.jenis", "label") but it showing error Schema hasn't been registered for model "kategori.jenis". Use mongoose.model(name, schema) any query suggestions? I've tried
{
$lookup: {
"from": "kategoris",
"localField": "produk.jenis",
"foreignField": "jenis",
"as": "jenisnya"
}
}
but it doesn't seem work, and returning an empty array instead. What should I do? Should I rearrange my schema?

Answer 1

You can try this,
$match your conditions
$unwind deconstruct produk array
$lookup with pipeline
$unwind deconstruct jenis array
$match match jenis._id
$project to show only _id and label
$unwind deconstruct in path produk.jenisnya
$group by _id and push in to produk
db.toko.aggregate([
{ $match: { _id: ObjectId("5f1d77aca53cb13980324c73") } },
{ $unwind: "$produk" },
{
$lookup: {
from: "kategoris",
as: "produk.jenisnya",
let: { pjid: "$produk.jenis" },
pipeline: [
{ $unwind: "$jenis" },
{ $match: { $expr: { $eq: ["$$pjid", "$jenis._id"] } } },
{ $project: { "jenis._id": 1, "jenis.label": 1 } }
]
}
},
{ $unwind: { path: "$produk.jenisnya" } },
{
$group: {
_id: "$_id",
produk: { $push: "$produk" },
// you can add otehr fields as well like alamat
alamat: { $first: "$alamat" }
}
}
])
Playground