将文档查询到 MongoDB 中的一个特定属性

Question

我想查询“doc”中的所有“doc”属性，就像一个嵌套的。我想你可以从下面的代码中进一步理解我想要解释的内容：

mongoose.connect("mongodb://127.0.0.1:27017/stationDB");

const docSchema = mongoose.Schema({
  naturka: String,
  address: String,
  coefficient: String,
  wheel: String,
  weight: Number
})

const stockSchema = mongoose.Schema({
  rollingStockNumber: String,
  docs: [docSchema]
});


const Doc = mongoose.model('Doc', docSchema);
const Stock = mongoose.model('Stock', stockSchema);

let doc;
  for(i=0; i<naturkaMinifiedArrayReady.length; i++){
    const doc = new Doc({
      naturka: naturkaMinifiedArrayReady[i],
      address: arrayOfWayPlanForm[i],
      coefficient: valueOfCarLength[i],
      wheel: numberOfWheels[i],
      weight: valueOfCarWeight[i]
    });
    docs = doc
  };

  const stock = new Stock({
    rollingStockNumber: rollingStock,
    docs: docs
  });
  stock.save((err) => {
    if (err) {
      res.redirect('/')
    }
  });

我已经插入了 8 个文档，但只返回了你看到的最后一个文档：

{ _id: new ObjectId("62a1ac800d9d39966878ebb8"), rollingStockNumber: '922698012567076507200129101700057022060000000', docs: [ { naturka: '08 94331444 0271 030 72240 00300 0012 0 0 0 0 01/00 96 04 105 0200 OXP', address: 'Toshkent', coefficient: '1.05', wheel: '4', weight: 50, _id: new ObjectId("62a1ac800d9d39966878ebb7") } ], __v: 0 } 

Answer 1

用 let 定义的 doc 是一个数组，但是你用 =.如果你用push把数据加到数组中，你的问题就解决了。

let docs = [];
  for(i=0; i<naturkaMinifiedArrayReady.length; i++){
    const doc = new Doc({
      naturka: naturkaMinifiedArrayReady[i],
      address: arrayOfWayPlanForm[i],
      coefficient: valueOfCarLength[i],
      wheel: numberOfWheels[i],
      weight: valueOfCarWeight[i]
    });
    docs.push(doc)
  };