我正在尝试显示数据库中的数据。我有3个Schema,将它们全部合并为一个。但是,合并数据未显示。我已经附上了我的3模式。
async-wait与try-catch配合良好,对我来说似乎很干净。我也尝试遵循mongoose populate。两者返回相同的结果。
需要提及:我是新手。因此,不要对遵循的最佳做法有个好主意。
Book Schema:
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);
图书控制器:
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 });
}
};
index.pug:
ul
each book in bookList
li
a(href=book.url) #{book.title}
| (#{book.author.name})
else
li No book Has Been Listed Yet...!
预期输出: apes and angels(约翰)
当前输出: apes and angels(NaN)
答案 0 :(得分:1)
请尝试以下代码。我认为这会起作用
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 });
}
};
答案 1 :(得分:1)
在我的查询中,我只需要添加以下回调:
exports.bookList = async(req, res, next) => {
try {
const bookList = await Book.find({}).populate('author').exec((err, bookList) => {
if (err) return bookInstanceList;
// console.log(bookList);
res.render('./book/index', { title: 'Book List', bookList: bookList});
});
} catch (error) {
res.status(500).json({ message: error.message });
}
};
主要问题是Schema中的箭头功能。我已经使用箭头功能来获取对象。但是,箭头功能不适用于对象。这里是参考:medium