javascript - Node.js:mongoose .populate() 未显示数据

Question

我正在尝试显示数据库中的数据。我有 3 个架构，将它们全部合并为一个。但是，合并数据并未显示。我已附上我的 3 个架构。

async-wait 与 try-catch 一起工作得很好，这对我来说似乎很干净。我也尝试过关注mongoose populate 。两者返回相同的结果。

需要说明的是:我是新手。因此，对于要遵循的最佳实践不太了解。

图书架构:

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

const BookSchema = new Schema({
    title: {
        type     : String,
        required : [true, 'Book Title is Required'],
        max      : 100,
        min      : 5,
        trim     : true,
        lowercase: true
    },
    author: {
        type    : Schema.Types.ObjectId,
        ref     : 'Author',
        required: [true, 'Author is Required']
    }
    genre: [{
        type: Schema.Types.ObjectId,
        ref : 'Genre'
    }]
}, { collection : 'book', timestamps: true });

BookSchema
.virtual('url')
.get(() => {
    return 'book/' + this._id;
});

module.exports = mongoose.model('Book', BookSchema);

作者架构:

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

const AuthorSchema = new Schema({
    firstName: {
        type     : String,
        required : [true, 'First Name is Required'],
        max      : 100,
        min      : 5,
        trim     : true,
        lowercase: true
    },
    lastName: {
        type     : String,
        required : [true, 'Last Name is Required'],
        max      : 100,
        min      : 5,
        trim     : true,
        lowercase: true
    }
}, { collection : 'author', timestamps: true });

AuthorSchema
.virtual('name')
.get(() => {
    return this.firstName + this.lastName;
});

module.exports = mongoose.model('Author', AuthorSchema);

流派架构:

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

const GenreSchema = new Schema({
    name: {
        type     : String,
        required : [true, 'Genre Name is Required'],
        max      : 100,
        min      : 3,
        trim     : true,
        lowercase: true
    }
}, { collection : 'genre', timestamps: true });

module.exports = mongoose.model('Genre', GenreSchema);

图书 Controller :

exports.bookList = async(req, res, next) => {
    try {
        const bookList = await Book.find({}).populate('author').exec();

        res.render('./book/index', { title: 'Book List', bookList: bookList});
    } catch (error) {
        res.status(500).json({ message: error.message });
    }
};

索引.pug:

ul
    each book in bookList
        li 
            a(href=book.url) #{book.title}
            |  (#{book.author.name})

    else
        li  No book Has Been Listed Yet...!

1. 网址未附加 ID
2. 未显示作者数据
3. 如果我使用.populate()，那么。它正在显示(Nan)
4. 如果我不使用 populate，它不会返回任何内容

预期输出: apes and angels (约翰)

当前输出: apes and angels (南)

Answer 1

请尝试以下代码。我想，它会起作用

exports.bookList = async(req, res, next) => {
    try {
        const bookList = await Book.find({}).populate('author').exec((error, list) => list);

        res.render('./book/index', { title: 'Book List', bookList: bookList});
    } catch (error) {
        res.status(500).json({ message: error.message });
    }
};