Javascript 获取时发送嵌套对象

我有一个非常基本的模式，里面有另一个叫做Vehicle的对象

let rentSchema = new Schema({
    code: {
        type: Number
    },
    vehicle: {
        type: mongoose.Schema.Types.ObjectId,
        ref: 'Vehicle'
    },
    ongoing: {
        type: Boolean,
        default: false
    }
}, {collection: 'RentCollection'});

在控制器中查找所有

exports.getRent = function (req, res) {
    // Find in the DB
     rentSchema.find({}, function (err, rent) {
        if (err) res.status(400).send(err);

        res.json(rent);
     });
 };

响应以租金数组的形式出现，但对象租金中缺少车辆对象。为什么呢

_id: "5e04c19d0a0a100f58bd64b5"
 __v: 0 
ongoing: false

必须使用“填充”方法来填充车辆对象

从文档：

rentSchema.
  findOne({}).
  populate('vehicle').
  exec(function (err, obj) {
    if (err) return handleError(err);
    console.log(obj);

  });

此外，在当前代码中，您尚未设置模型：

---

RentCollection=mongoose.model'RentCollection'，rentSchema

以下是一步一步的解释，以使其发挥作用：

1-首先，您需要创建一个模型并按如下方式导出：

{
    "_id": "5e0f465205515667746fd51a",
    "name": "Vehicle 1",
    "__v": 0
}

{
    "ongoing": false,
    "_id": "5e0f46b805515667746fd51d",
    "code": 1,
    "vehicle": "5e0f465205515667746fd51a",
    "__v": 0
}

rent.js

const mongoose = require("mongoose");
const Schema = mongoose.Schema;

let rentSchema = new Schema(
  {
    code: {
      type: Number
    },
    vehicle: {
      type: mongoose.Schema.Types.ObjectId,
      ref: "Vehicle"
    },
    ongoing: {
      type: Boolean,
      default: false
    }
  },
  { collection: "RentCollection" }
);

module.exports = mongoose.model("Rent", rentSchema);

2-假设您拥有此车型：

vehicle.js

const mongoose = require("mongoose");
const Schema = mongoose.Schema;

let vehicleSchema = new Schema(
  {
    name: String
  },
  { collection: "VehicleCollection" }
);

module.exports = mongoose.model("Vehicle", vehicleSchema);

3-首先，让我们在VehicleCollection中创建一个如下所示的车辆：

{
    "_id": "5e0f465205515667746fd51a",
    "name": "Vehicle 1",
    "__v": 0
}

{
    "ongoing": false,
    "_id": "5e0f46b805515667746fd51d",
    "code": 1,
    "vehicle": "5e0f465205515667746fd51a",
    "__v": 0
}

4-然后让我们使用此车辆id在RentCollection中创建一个租金文档，如下所示：

{
    "_id": "5e0f465205515667746fd51a",
    "name": "Vehicle 1",
    "__v": 0
}

{
    "ongoing": false,
    "_id": "5e0f46b805515667746fd51d",
    "code": 1,
    "vehicle": "5e0f465205515667746fd51a",
    "__v": 0
}

5-现在我们可以使用以下代码，对车辆进行租赁

const Rent = require("../models/rent"); //todo: change to path to the rent.js

exports.getRent = function(req, res) {
  Rent.find({})
    .populate("vehicle")
    .exec(function(err, rent) {
      if (err) {
        res.status(500).send(err);
      } else {
        if (!rent) {
          res.status(404).send("No rent found");
        } else {
          res.json(rent);
        }
      }
    });
};

6-结果将是：

[
    {
        "ongoing": false,
        "_id": "5e0f46b805515667746fd51d",
        "code": 1,
        "vehicle": {
            "_id": "5e0f465205515667746fd51a",
            "name": "Vehicle 1",
            "__v": 0
        },
        "__v": 0
    }
]

---

消息：尚未为车型注册架构。↵使用mongoose.modelname，schemaaah，您还没有设置模型。最新答案