const Client = require('promise-mysql-client') // connect to server in synchronous code const mysql = new Client('localhost', 3306, 'test', 'root', 'root') // you can query here that the client has already connected to the server :) mysql.query("insert into users values (1, 'xavier')").then(res => { ... }) // imitate the http request after 3 seconds setTimeout(() => { mysql.query("select * from users where id = 1") .then(user => { return mysql.query(`update users set name = 'xvrzhao' where id = ${user.id}`) }) .then(res => { if (res.numOfAffectedRows === 1) console.log('updated') }) .catch(err => { ... }) }, 3000)

const sqlStr1 = "sql statement" const sqlStr2 = "sql statement" const sqlStr3 = "sql statement" mysql.query(sqlStr1).then(() => mysql.query(sqlStr2)) mysql.query(sqlStr3) // query sequence: sqlStr1 -> sqlStr3 -> sqlStr2

const sqlStr1 = "sql statement" const sqlStr2 = "sql statement" const sqlStr3 = "sql statement" ;(async () => { await mysql.query(sqlStr1) await mysql.query(sqlStr2) })() ;(async () => { await mysql.query(sqlStr3) })() // query sequence: sqlStr1 -> sqlStr3 -> sqlStr2

mysql.close().then(() => { console.log('disconnected') mysql.connect() // will connect at process.nextTick  return }).then(() => { // promise.then will been executed after process.nextTick console.log('connected') mysql.query("delete from users where id = 12") })