mongooseをnodejsで使用して深く入れ子になったデータを選択する方法

Question

私はnodejsとmongooseを初めて使っています。カテゴリとサブカテゴリを持つカテゴリドキュメントを作成しました。今私はレベル3から値を選択したいと私は成功を得ることができません。ここで

は私のカテゴリが

[{ 
"_id": "58eb0ee37c1f817864b5b863", 
"name": "Electronics", 
"slug": "electronics", 
"order": 1, 
"__v": 0, 
"subCats": [{ 
    "name": "Mobiles", 
    "slug": "mobiles", 
    "_id": "58eb0ee37c1f817864b5b867", 
    "subCats": [{ 
     "name": "Apple", 
     "slug": "apple", 
     "_id": "58eb0ee37c1f817864b5b872", 
     "params": ["RAM", "Storage", "Primary Camera", "Front Camera", "Battery", "Processor", "Display Size", "Resolution", "Resolution Type", "GPU", "Operating System"] 
    }, { 
     "name": "HTC", 
     "slug": "htc", 
     "_id": "58eb0ee37c1f817864b5b871", 
     "params": ["RAM", "Storage", "Primary Camera", "Front Camera", "Battery", "Processor", "Display Size", "Resolution", "Resolution Type", "GPU", "Operating System"] 
    }, { 
     "name": "Mi", 
     "slug": "mi", 
     "_id": "58eb0ee37c1f817864b5b870", 
     "params": ["RAM", "Storage", "Primary Camera", "Front Camera", "Battery", "Processor", "Display Size", "Resolution", "Resolution Type", "GPU", "Operating System"] 
    }, { 
     "name": "OPPO", 
     "slug": "oppo", 
     "_id": "58eb0ee37c1f817864b5b86f", 
     "params": ["RAM", "Storage", "Primary Camera", "Front Camera", "Battery", "Processor", "Display Size", "Resolution", "Resolution Type", "GPU", "Operating System"] 
    }, { 
     "name": "Samsung", 
     "slug": "samsung", 
     "_id": "58eb0ee37c1f817864b5b86e", 
     "params": ["RAM", "Storage", "Primary Camera", "Front Camera", "Battery", "Processor", "Display Size", "Resolution", "Resolution Type", "GPU", "Operating System"] 
    }, { 
     "name": "Lenovo", 
     "slug": "lenovo", 
     "_id": "58eb0ee37c1f817864b5b86d", 
     "params": ["RAM", "Storage", "Primary Camera", "Front Camera", "Battery", "Processor", "Display Size", "Resolution", "Resolution Type", "GPU", "Operating System"] 
    }, { 
     "name": "Motorola", 
     "slug": "motorola", 
     "_id": "58eb0ee37c1f817864b5b86c", 
     "params": ["RAM", "Storage", "Primary Camera", "Front Camera", "Battery", "Processor", "Display Size", "Resolution", "Resolution Type", "GPU", "Operating System"] 
    }, { 
     "name": "LG", 
     "slug": "lg", 
     "_id": "58eb0ee37c1f817864b5b86b", 
     "params": ["RAM", "Storage", "Primary Camera", "Front Camera", "Battery", "Processor", "Display Size", "Resolution", "Resolution Type", "GPU", "Operating System"] 
    }, { 
     "name": "Huawei", 
     "slug": "huawei", 
     "_id": "58eb0ee37c1f817864b5b86a", 
     "params": ["RAM", "Storage", "Primary Camera", "Front Camera", "Battery", "Processor", "Display Size", "Resolution", "Resolution Type", "GPU", "Operating System"] 
    }, { 
     "name": "Nokia", 
     "slug": "nokia", 
     "_id": "58eb0ee37c1f817864b5b869", 
     "params": ["RAM", "Storage", "Primary Camera", "Front Camera", "Battery", "Processor", "Display Size", "Resolution", "Resolution Type", "GPU", "Operating System"] 
    }, { 
     "name": "Microsoft", 
     "slug": "microsoft", 
     "_id": "58eb0ee37c1f817864b5b868", 
     "params": ["RAM", "Storage", "Primary Camera", "Front Camera", "Battery", "Processor", "Display Size", "Resolution", "Resolution Type", "GPU", "Operating System"] 
    }] 
}, { 
    "name": "Mobile Accessories", 
    "slug": "mobile-accessories", 
    "_id": "58eb0ee37c1f817864b5b864", 
    "subCats": [{ 
     "name": "Mobile Cases", 
     "slug": "mobile-cases", 
     "_id": "58eb0ee37c1f817864b5b866", 
     "params": ["Model", "type"] 
    }, { 
     "name": "Headphones & Headsets", 
     "slug": "headphones-headsets", 
     "_id": "58eb0ee37c1f817864b5b865", 
     "params": [] 
    }] 
}] 

どのように見えるかをここで私は以下のAppleカテゴリの_idと名前を取得したいのですが、データを使用でき

router.get('/getparms/:cat', function (req, res, next){ 

categoriesModel.find({ 
    "slug" : req.params.cat 
} ,function(err, categories){ 
    if (err) throw err; 

    res.send(categories); 
})}); 

Answer 1

を取得するためにやっているものですです集約フレームワーク。詳細情報はhereとhereです。

このコードは正常に動作します。ここで

MyModel.aggregate([ 
 
    { 
 
     "$match": { 
 
      "subCats.subCats.slug": req.params.cat 
 
     } 
 
    }, 
 
    { "$unwind": "$subCats" }, 
 
    { "$unwind": "$subCats.subCats" }, 
 
    { 
 
     "$match": { 
 
      "subCats.subCats.slug": req.params.cat 
 
     } 
 
    }, 
 
    { 
 
     "$project": { 
 
      "data":"$subCats.subCats" 
 
     } 
 
    } 
 
], function (err, result) { 
 
    console.log(result); 
 
})

我々は$の試合で他のunnessary書類を減らすために最初の文書にマッチし、二回SUBCATSを巻き戻した後、我々は再びパラメータをマッチして、最後に我々は唯一中わたのSUBCATSドキュメントを返しました。