node.js - 我的 Mongoose 关系出了什么问题？

Question

我正在学习 Mongoose 关系并陷入这个问题......有人告诉我我错在哪里......？有没有更好的方法来做到这一点..？

Employee.js

const mongoose = require("mongoose");
const { departmentSchema, addDepartment } = require("./Departments");

const schema = new mongoose.Schema();

const employeeModel = mongoose.model("Employee", {
  Name: { type: String, required: true, minlength: 5, maxlength: 50 },
  Department: departmentSchema
});

async function addEmployee(Employee, Department, Language, Framework) {
  const result = await new employeeModel({
    ...Employee,
    Department: addDepartment(Department, Language, Framework)
  });
  return await result.save();
}

Department.js

const mongoose = require("mongoose");
const { languageSchema, addLanguage } = require("./Language");

const departmentSchema = new mongoose.Schema({
  Depart: { type: String, required: true, minlength: 5, maxlength: 50 },
  Languages: languageSchema
});

const DepartmentModel = mongoose.model("Department", departmentSchema);

async function addDepartment(Department, Language, Framework) {
  const result = await new DepartmentModel({
    ...Department,
    Languages: addLanguage(Language, Framework)
  });
  return await result.save();
}

module.exports = {
  departmentSchema,
  addDepartment
};

语言.js

const mongoose = require("mongoose");
const { frameworkSchema, addFramework } = require("./Frameworks");

const languageSchema = new mongoose.Schema({
  Language: { type: String, required: true },
  Framework: [frameworkSchema]
});

const languageModel = mongoose.model("Language", languageSchema);

async function addLanguage(Language, Framework) {
  const result = await new languageModel({
    ...Language,
    Framework: addFramework(Framework)
  });
  return await result.save();
}

module.exports = {
  languageSchema: languageSchema,
  addLanguage
};

Framework.js

const mongoose = require("mongoose");

const frameworkSchema = new mongoose.Schema({
  Name: { type: String, required: true, minlength: 4, maxlength: 50 },
  Version: { type: String, required: true, minlength: 1, maxlength: 50 }
});

const frameworkModel = mongoose.model("Framework", frameworkSchema);

async function addFramework(Framework) {
  const result = await new frameworkModel(...Framework);
  return await result.save();
}

module.exports = {
  frameworkSchema,
  addFramework
};

Framework.js 错误

Found non-callable @@iterator

我想做的是

1. 员工 ->
2. 姓名
3. 部门 ->
4. 出发
5. 语言 ->
6. 语言名称
7. 框架 ->
8. 框架名称
9. 框架版本

每个 -> 代表一个新对象(集合)

我知道对于像我这样的新手来说这有点复杂......我是 MySql 数据库用户，我喜欢它，但现在我正在尝试掌握 NoSql...

提前致谢:)

Answer 1

我将向您展示一个示例:假设您已经有 employSchema 了:

const {Schema} = mongoose;
const employeeModel = mongoose.model("Employee", new Schema({
  Name: { type: String, required: true, minlength: 5, maxlength: 50 },
  Department: {type: Schema.Types.ObjectId, ref: "Department"}
}));

在上面的模型中，我使用 ref 属性通过 ObjectId 连接到 Department 模型(这意味着 Department 集合中的“_id”属性)。

例如:您将创建一个新的employeeModel，如下所示:

let newEmployee = new employeeModel("Employee Name", Department ID here).

你绝对会做相反的事或为别人做事。并且需要使用.populate()函数来查询数据库。示例:

employModel.find({}).populate("Department").exec(callback what you want to do);

您可以阅读官方文档:https://mongoosejs.com/docs/populate.html