Js全栈开发之NoSQL数据库使用(MongoDB和Redis)

NoSQL数据库使用

接着上一篇《Js全栈开发之Sequelize用法详解(MySQL)》来继续学习koa2，上一篇总结了MySQL等关系型数据库的使用和ORM框架Sequelize的用法，本篇将汇总NoSQL类数据库的用法，如MongoDB和Redis等，总结一些平时比较常用的api及语法。

1. MongoDB使用

1.1 mongoose库安装

npm install mongoose -save

1.2 数据库连接

// 连接数据库
const mongoose = require('mongoose');
mongoose.connect('mongodb://xxx.xxx.xxx.xxx:27017/admin',{
    user:'root',
    pass:'xxxxxx',
    poolSize: 10,
    useNewUrlParser: true,
    useUnifiedTopology: true 
});
const mongodbConn = mongoose.connection;
mongodbConn.on('error', err => {
    console.error(err);
});
mongodbConn.once('open', ()=> {
    console.log('连接成功!')
})

1.3 声明创建保存model对象

const mongodbConn = mongoose.connection;
// 声明和创建model对象
const cateqorySchema = new mongoose.Schema({
    name:{
        type:String,
        index:true,
        unique:true
    },
    description: String,
    createArt:{
        type:Date,
        default: Date.now
    }
});
const Category = mongodbConn.model('Category',cateqorySchema);
// 插入对象方法1
const categoryObj = new Category({
    name:'编程',
    description:'编程开发技术类'
});
categoryObj.save(err =>{
    if(err){
        console.error(err)
        return;
    }
    else{
        console.log('save success!');
    }
});
// 插入对象方法2
Category.create({
    name:'摄影',
    description:'摄影户外类'
},(err, category)=>{
    if(err){
        console.error(err);
    }else{
        console.log(category);
    }
})

1.4 查询修改删除对象数据

// 查找对象
 Category.find({
    name: '编程'
},(err,res)=>{
    if(err){
        console.log(err)
    }else{
        console.log(res);
    }
    mongodbConn.close();
});
// 更新对象
Category.update({
    name: '编程'
},{
    description:'技术开发'
}).then((err,res)=>{
    if(err){
        console.log(err)
    }else{
        console.log(res);
    }
    mongodbConn.close();
});
// 删除对象
Category.update({
    name: '编程'
}).then((err,res)=>{
    if(err){
        console.log(err)
    }else{
        console.log(res);
    }
    mongodbConn.close();
});

2. mongoose 官方文档

• 英文文档：https://mongoosejs.com/
• 中文文档： http://www.mongoosejs.net/

3. Redis使用

3.1 安装Redis库

npm install redis -save

3.2 连接Redis

const redis = require('redis');
const redisLink = 'redis://xxx.xxx.xxx:6379'
const opts = {
	auth_pass: 'xxxxxx',
}
const redisClient = redis.createClient(redisLink, opts)
redisClient
.on('error', err => console.log('------ Redis connection failed ------' + err))
.on('connect', () => console.log('------ Redis connection succeed ------'))

3.3 使用Redis

// 储存字符串
redisClient.set('name','dahlin',redis.print)
redisClient.get('name', function(err,value){
    if(err) throw err;
    console.log('name:'+value);
});
// 用哈希存储数据
redisClient.hmset('dahlin',{
    'item':'koa2learn',
    'chapter':'use redis'
});
redisClient.hgetall('dahlin', function(err,obj){
    console.log(obj)
});
redisClient.hkeys("dahlin",function(err,replies){
    replies.forEach(function(reply,i){
        console.log(i+"->"+reply);
    })
});
// 用列表存取数据
redisClient.lpush('mylist','koa1',redis.print);
redisClient.lpush('mylist','koa2',redis.print);
redisClient.lrange('mylist',0,-1,function(err,items){
    if(err){
        console.log(err);
    }else{
        items.forEach(function(item,i){
            console.log(i+":"+item);
        })
    }
});
// 用集合存取数据
redisClient.sadd('myset','koa1',redis.print);
redisClient.sadd('myset','koa2',redis.print);
redisClient.smembers('myset',function(err,items){
    if(err){
        console.log(err);
    }else{
        console.log(items);
    }
});

3.4 使用同步方式

//封装redis  util/redis.js
const redis = require("redis");
const { promisify } = require('util');
//Redis 命令参考  http://doc.redisfans.com/index.html  

/**
 * 
 * @param {*} db  需要切换的DB，不传则默认DB 0
 */
function Client(num){
    let db = num || 0
    let client = redis.createClient({db});

    //需要使用同步函数，按照如下定义即可
    this.exists =  promisify(client.exists).bind(client);
    this.keys =  promisify(client.keys).bind(client);

    this.set = promisify(client.set).bind(client);
    this.get = promisify(client.get).bind(client);
    this.del = promisify(client.del).bind(client);
    this.incr = promisify(client.incr).bind(client);
    this.decr = promisify(client.decr).bind(client);

    this.lpush = promisify(client.lpush).bind(client);

    this.hexists =  promisify(client.hexists).bind(client);
    this.hgetall = promisify(client.hgetall).bind(client);
    this.hset = promisify(client.hset).bind(client);
    this.hmset = promisify(client.hmset).bind(client);
    this.hget = promisify(client.hget).bind(client);
    this.hincrby = promisify(client.hincrby).bind(client);
    this.hdel = promisify(client.hdel).bind(client);
    this.hvals = promisify(client.hvals).bind(client);
    this.hscan = promisify(client.hscan).bind(client);

    this.sadd = promisify(client.sadd).bind(client);
    this.smembers = promisify(client.smembers).bind(client);
    this.scard = promisify(client.scard).bind(client);
    this.srem = promisify(client.srem).bind(client);
    return this;
}
module.exports = Client

// 同步方式使用
const Client = require('../util/redis')
let client = new Client(3); //gateway在REDIS中的默认DB 为0
let old = await client.exists(ip);//先查询
if (!old) {
    await client.set(ip, value);
}

4. Redis参考博文

• node使用redis https://www.w3cways.com/2364.html
• Node.js Redis 的使用 https://blog.csdn.net/q282176713/article/details/80580886