MongoDB 集合关联

const mongoose = require('mongoose')

mongoose.connect('mongodb://164.red/test', { useUnifiedTopology: true })
    .then(res => console.log('数据库连接成功'))
    .catch(res => console.log('数据库连接失败'))

// 用户集合规则
const userSchema = new mongoose.Schema({ name: String})

// 文章集合规则
const postSchema = new mongoose.Schema({ 
    title: String,
    // 关联集合
    author: {
        type: mongoose.Schema.Types.ObjectId,
        ref: 'User'
    }
})

// 用户集合
const User = mongoose.model('User', userSchema )

// 文章集合
const Post = mongoose.model('Post', postSchema)

User.create({name: 'zhangsan'}).then(res => console.log(res))

Post.create({title: 'fsdfs', author: '5e0c4c2a237809c3ae003992'}).then(res => console.log(res))

Post.find().populate('author').then(res=> console.log(res))