如何使用节点 js 从猫鼬模式中读取嵌套数组元素？

Question

她是我的猫鼬用户模式代码：

var mongoose = require('mongoose');

var userSchema = new mongoose.Schema({
  email: {
    type: String,
    unique: true,
    required: true
  },
  name: {
    type: String,
    required: true
  },
 
  Addtasks : [{
    website: String,
    otherdetails: String,
    exampleRadios: String,
    deadline: Date,
    Date: String,
    fileName: String,
    Bigpaths:[]
  }]

});

module.exports = mongoose.model('User', userSchema);

这是以json格式存储的mongodb数据：

{
    "_id" : ObjectId("5f378bec5bd30f3248ffae59"),
    "email" : "vikasthapar95@gmail.com",
    "name" : "Vikas Yadav",
    "Addtasks" : [ 
        {
            "website" : "grumpytext.com",
            "keywords" : "article importance, article generation, article quality",
            "words" : 1234567,
            "topic" : "How article is generated?",
            "_id" : ObjectId("5f379c7164a77a338483704c"),
            "Bigpaths" : [ 
                {
                    "path" : "public\\files\\chrome.VisualElementsManifest.xml",
                    "name" : "chrome.VisualElementsManifest.xml"
                }, 
                {
                    "path" : "public\\files\\chrome_proxy.exe",
                    "name" : "chrome_proxy.exe"
                }, 
                {
                    "path" : "public\\files\\master_preferences",
                    "name" : "master_preferences"
                }
            ]
        }
    ],
}

现在我想要的是仅迭代位于 Addtasks 数组内的 Bigpaths 嵌套数组，并从中获取其通过循环的每个对象的数据。我怎样才能做到这一点？我尝试过一种 populate() 的东西，但似乎没有帮助。请帮忙！！

期望的结果：

[
                {
                    "path" : "public\\files\\chrome.VisualElementsManifest.xml",
                }, 
                {
                    "path" : "public\\files\\chrome_proxy.exe",
                }, 
                {
                    "path" : "public\\files\\master_preferences",
                }

]

UI 端（车把）的预期结果：

Path 1 = public\\files\\chrome.VisualElementsManifest.xml
Path 2 = public\\files\\chrome_proxy.exe
Path 3 = public\\files\\master_preferences

Answer 1

这将结合根目录下的所有文档路径，

• $unwind解构Addtasks数组
• $unwind解构Addtasks.Bigpaths数组
• $replaceRoot 将在新根目录中替换 path: Addtasks.Bigpaths.path

db.collection.aggregate([
  { $unwind: "$Addtasks" },
  { $unwind: "$Addtasks.Bigpaths" },
  {
    $replaceRoot: {
      newRoot: { path: "$Addtasks.Bigpaths.path" }
    }
  }
])

Playground

---

用于访问文档中的项目，

let paths = [];
data.Addtasks.forEach(function(Addtasks){
    Addtasks.Bigpaths.forEach(function(Bigpaths){
        paths.push({name: Bigpaths.name});
    });
})
console.log(paths);