populate 关联查询
作者:互联网
模型
db.js
// 连接数据库 const mongoose = require('mongoose') // eggadmin 用户名 // 123456 密码 // 127.0.0.1:27017 服务器及端口 // eggcms 数据库 mongoose.connect('mongodb://eggadmin:123456@127.0.0.1:27017/eggcms', function (err, data) { if (err) { console.log(err, '数据库连接成功') return; } console.log('数据库连接成功') }) module.exports = mongoose
article.js (定义文档的时候需要使用 ref 来关联 model 模型名称)
const mongoose = require('./db') // 文章表结构 const ArticleSchema = new mongoose.Schema({ title: { type: String, unique: true }, cid: { // 文章分类id type: mongoose.Schema.Types.ObjectId,
ref: 'Articlecate', // cid 外键与 Articlecate 模型关联 }, author_id: { // 用户的ID type: mongoose.Schema.Types.ObjectId,
ref: 'User', // author_id 外键关联 User 模型 }, author_name: { // 用户姓名 type: String }, description: String, content: String }) module.exports = mongoose.model('Article', ArticleSchema, 'article')
articlecate.js
const { Schema } = require('mongoose') const mongoose = require('./db') // 文章分类表 const ArticleCateSchema = new mongoose.Schema({ title: { type: String, unique: true }, description: String, addtime: { type: Date, } }) module.exports = mongoose.model('ArticleCate', ArticleCateSchema, 'articlecate')
user.js
const mongoose = require('./db') // 用户表结构 const UserSchema = new mongoose.Schema({ username: { type: String, unique: true }, password: String, name: String, age: Number, sex: String, tel: Number, status: { type: Number, default: 1 } }) module.exports = mongoose.model('User', UserSchema, 'user')
查询
const ArticleCateModel = require('./model/articlecate') const ArticleModel = require('./model/article') const UserModel = require('./model/user') ArticleModel.find({}).populate('cid').populate('author_id').exec(function (err, docs) { console.log(docs) })
- 关联查询时需要引入对应的 model
- 通过 populate 指向外键
- 通过 exec 获取结果
标签:const,String,populate,require,关联,mongoose,model,查询,type 来源: https://www.cnblogs.com/xiebenyin-/p/16367425.html