MongoDB（Mongoose）数据库结构题

Question

我目前正在学习 Mongoose 和 nodeJS。我必须创建一个数据库，其中保存了课程注册和学生每门课程的分数。每个科目还与一位老师相关联。想想数据库的结构。确保您可以争论为什么要通过“嵌入”或“参考”连接数据。还要考虑在哪里使用索引和唯一索引。

我目前的想法：

• 一个学生有多个课程
• 一个课程有多个学生
• 学生在一门课程上获得多个分数
• 一门课程有一位老师

我尝试制作以下猫鼬方案：

学生架构：

const mongoose = require("mongoose");
const studentSchema = new mongoose.Schema({
        name: {
            type: String,
            minLength: 3,
            trim: true,
            lowercase: true,
            validate: {
                validator: (value) => /^[a-z ]+$/.test(value),
                message: (props) => `${props.value} is not a valid name!`
            },
            required: [ true, "Name is required" ]
        },
        id: {
            type: Number,
            index: { unique: true },
            min: [ 1, "ID must be greater than 0" ],
            required: [ true, "ID is required" ]
        },
        courses : [ { type: mongoose.Schema.Types.ObjectId, ref: "Course" } ]
    },
    { collection: "students" }
);

module.exports = mongoose.model("Student", studentSchema );

课程架构：

const mongoose = require("mongoose");
const courseSchema = new mongoose.Schema({
        title: {
            type: String,
            minLength: 3,
            trim:true,
            lowercase:true,
            validate: {
                validator: (value) => /^[a-z ]+$/.test(value),
                message: (props) => `${props.value} is not a valid course title`
            },
            required: [true, "Course title is required"]
        },
        teacher: {
            type: String,
            minLength: 3,
            trim: true,
            lowercase: true,
            validate: {
                validator: (value) => /^[a-z ]+$/.test(value),
                message: (props) => `${props.value} is not a valid teacher name`
            },
            required: [true, "teacher is required"]
        },
        student : { type: mongoose.Schema.Types.ObjectId, ref: "Student" }
    },
    { collection: "courses" }
);

module.exports = mongoose.model("Course", courseSchema );

我目前面临的问题：

1. 在 StudentSchema 中，我使用的是 Id，因为我想要 1、2、3、4 等而不是从 MongoDB 随机生成的 id。这是正确的做法吗？
2. 如何将分数添加到数据库中以及将其放置在哪里？

Answer 1

这真的是见仁见智。

如果您需要每个文档的唯一 ID，您应该让 Mongo 处理它。这是有原因的。

在我看来，您应该在 courses 架构中添加一个 scores 数组。

const mongoose = require("mongoose");
const courseSchema = new mongoose.Schema({
        title: {
            type: String,
            minLength: 3,
            trim:true,
            lowercase:true,
            validate: {
                validator: (value) => /^[a-z ]+$/.test(value),
                message: (props) => `${props.value} is not a valid course title`
            },
            required: [true, "Course title is required"]
        },
        teacher: {
            type: String,
            minLength: 3,
            trim: true,
            lowercase: true,
            validate: {
                validator: (value) => /^[a-z ]+$/.test(value),
                message: (props) => `${props.value} is not a valid teacher name`
            },
            required: [true, "teacher is required"]
        },
        student : { type: mongoose.Schema.Types.ObjectId, ref: "Student" },
        scores: [{
            score: Number, // the grade
            assignment_id: mongoose.Schema.Types.ObjectId// the id to the test/quiz/homework/etc.. which was graded
        }],
        // You could also just have an array of numbers (scores)
        scores: { type: [Number] }
    },
    { collection: "courses" }
);

module.exports = mongoose.model("Course", courseSchema );