Express连接MySQL及数据库连接池技术实例

var mysql = {
host: “127.0.0.1”,//这是数据库的地址
user: “root”,//需要用户的名字
password: “root23”,//用户密码 ，如果你没有密码，直接双引号就是
database: “info”,//数据库名字
port:3306//数据库使用的端口号
}
module.exports = mysql;//用module.exports暴露出这个接口

const express = require(‘express’);
const router = express.Router();
//导入MySQL 模块
const mysql = require(‘mysql’);
//导入配置文件
const db = require(‘../config/configdb’);

router.get(‘test’,(req,res)=>{
//创建数据库连接对象
let conn = mysql.createConnection(db);
//查询bookinfo中所有数据
conn.query(‘select * from student’,(err,results,fieldes)=>{
//fieldes表示具体的字段
if(err){
throw err;
}
res.send(results);
})
//关闭数据库链接
conn.end((err)=>{
console.log(err);
})
module.exports = router;

var dbRouter = require(‘./routes/option’)
app.use(‘/db’,dbRouter);

var mysql = require(‘mysql’);

var pool = mysql.createPool(options);

//创建数据库连接池
const pool = mysql.createPool({
connectionLimit:20,
host:’localhost’,
port:3306,
user:’root’,
password:’123456′,
database:’info’
})
//导出数据库连接池对象
module.exports = pool;

pool.getConnection((err, conn) => {
if (err) {
console.log(err)
} else {
let sql = ‘select * from bookinfo’;
conn.query(sql, (err, results) => {
if (err) {
console.log(err)
} else {
res.send(results);
conn.release();
}
})
}
})

conn.release();

const express = require(‘express’);
const pool = require(‘../config/dbmysql’);

const router = express.Router();
/*
* http://localhost:3000/dbmysql/books
* */
router.get(‘/books’,(req,res)=>{
//从数据库连接池中获取数据库连接对象
pool.getConnection((err,conn)=>{
if(err){
console.log(err)
}else {
let sql = ‘select * from bookinfo’;
conn.query(sql,(err,results)=>{
if (err) {
console.log(err)
}else {
res.send(results);
conn.release();
}
})
}
})
})
module.exports = router;