nodejs各类数据库常用方法封装

在Node.js中，常见的数据库有MySQL、MongoDB、Redis等。下面是各类数据库常用方法的封装示例。

MySQL数据库常用方法封装示例：

const mysql = require('mysql');// 创建连接池const pool = mysql.createPool({host: 'localhost',user: 'root',password: 'password',database: 'mydb',connectionLimit: 10});// 查询数据function query(sql, values) {return new Promise((resolve, reject) => {pool.getConnection((err, connection) => {if (err) {reject(err);} else {connection.query(sql, values, (err, results) => {connection.release();if (err) {reject(err);} else {resolve(results);}});}});});}module.exports = {query};

MongoDB数据库常用方法封装示例：

const mongoose = require('mongoose');// 连接数据库mongoose.connect('mongodb://localhost/mydb', {useNewUrlParser: true,useUnifiedTopology: true});const db = mongoose.connection;// 定义数据模型const userSchema = new mongoose.Schema({name: String,age: Number});const User = mongoose.model('User', userSchema);// 查询数据function findUser(query) {return User.find(query).exec();}module.exports = {findUser};

Redis数据库常用方法封装示例：

const redis = require('redis');const client = redis.createClient();// 设置数据function set(key, value) {return new Promise((resolve, reject) => {client.set(key, value, (err, reply) => {if (err) {reject(err);} else {resolve(reply);}});});}// 获取数据function get(key) {return new Promise((resolve, reject) => {client.get(key, (err, reply) => {if (err) {reject(err);} else {resolve(reply);}});});}module.exports = {set,get};

这些封装示例只是简单的示范，实际应用中还需要根据具体的业务需求进行适当的封装和错误处理。