首先说说mongoose是做什么的？mongoose是在nodejs中用来操作mongodb数据库，由于其使用方便，深得许多nodejser的热爱。
安装yarn add mongoose
//引入mogoose模块
const mongoose = require('mongoose')
//连接mongodb
mongoose.connect('mongodb://localhost:27017/mydb')
//连接成功
mongoose.connection('connected',()=>{
console.log('connect success!');
})
//连接失败
mongoose.connection('error',(err)=>{
console.log('connect error,'+err);
})
//连接断开
mongoose.connection('disconnected',()=>{
console.log('connect disconnected');
})
schema 可以定义 mongodb中collection的数据格式
//引入mogoose模块
const mongoose = require('mongoose')
const Schema = mongoose.Schema;
//连接mongodb
mongoose.connect('mongodb://localhost:27017/mydb')
//定义User Schema
const UserSchema = new Schema({
username:String,
password:String,
age:Number,
loginAt:Date
})
model是由Schema生成的实例模型，可以对mongodb进行操作
//定义User Schema
const UserSchema = new Schema({
username:String,
password:String,
age:Number,
loginAt:Date
})
const User = mongoose.model('User',UserSchema)
//定义User Schema
const UserSchema = new Schema({
username:String,
password:String,
age:Number,
loginAt:Date
})
const User = mongoose.model('User',UserSchema)
//插入数据
let user = new User({
username:'Tony'，
password:'ps',
age:20,
loginAt:new Date()
})
//保存
user.save((errr,res)=>{
if(err){
return console.track(err)
}
console.log(res)
})
//更新
User.update({username:'tony'},{age:30},(err,doc)=>{
if(err){
return console.track(err)
}
console.log('update success!')
})
//删除
User.remove({age:30},(err,doc)=>{
if(err){
return console.track(err)
}
console.log('delete success!')
})
//查询
User.find({username:'tony'},(err,doc)=>{
if(err){
return console.track(err)
}
console.log(doc);
})
//数量
User.count({age:20},(err,docs)=>{
if(err){
return console.track(err)
}
console.log(docs);
})
