MySQL入门

安装

安装MySQL，MySQL Workbench

到bin目录下启动下列命令，能获得默认密码

mysqld --initialize --console

启动MySQL 

mysqld --console

启动MySQL Workbench连接mysql数据库

show databases

node连接mysql

因版本问题，使用的是8.0最新的版本会报错

Client does not support authentication protocol requested by server; consider upgrading MySQL client

解决方案1

USE mysql;
ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '123456';
FLUSH PRIVILEGES;

node连接代码

const mysql = require('mysql')

const connection = mysql.createConnection({
  host: 'localhost',
  user: 'root',
  password: '123456',
  port: '3306',
  database: 'myblog'
})

connection.connect()

var sql = 'SELECT * FROM users'

connection.query(sql, (err, res) => {
  if (err) {
    console.log(err)
    return
  }
  console.log(res)
})

connection.end()

改造成Promise

const exec = sql => {
  return new Promise((resolve, reject) => {
    connection.query(sql, (err, res) => {
      if (err) reject(err)
      else {
        resolve(res)
      }
    })
  })
}