一. 环境版本

1. node v13.5.0

2. npm v6.13.4

3. mysql v8.0.19

3. egg.js v2.15.1

4. egg-mysql  v3.0.0

二. 安装mysql

1. 安装mysql ，系统可自动选择您需要下载的版本，选择第一个 Download 进行下载

2. 进入傻瓜式安装，其中需要注意的一点是下面一步

如果选择 use Strong password Encryption 选项，为强密码模式，则会将你输入的密码进行加密，会在后面服务器与客户端连接时报错

如果选择 use Legacy Password Encryption 选项，为普通模式

为了方便，我们选择第二种普通模式，如已经安装选择了第一种，也没有关系，可通过终端进行修改为普通模式，(提示：在下面??【四-7，8，9】题中提到)

三，打开 【系统偏好设置】,将mysql 开启

四，打开终端，

1.  查看MySQL是否存   执行语句为： ps aux | grep mysql 

2. 执行命令切换到这个目录底下，执行语句为：cd /usr/local/mysql/

3. 切换到bin目录下，执行语句为：cd bin/

4. 登录MySQL，输入指令后根据提示输入初始密码 执行语句为：./mysql -u root -p

5. 如密码错误，或密码复杂需修改初始密码，执行语句为：SET PASSWORD FOR ‘root’@‘localhost’ = PASSWORD(‘新密码’);

6. 刷新权限 ，执行语句为：FLUSH PRIVILEGES;

7. 如需要将加密模式改为普通模式，执行语句为：ALTER USER ‘root‘@‘localhost‘ IDENTIFIED BY ‘password‘ PASSWORD EXPIRE NEVER; 

8. 更新用户密码，执行语句为：ALTER USER ‘root‘@‘localhost‘ IDENTIFIED WITH mysql_native_password BY ‘password‘;

9. 刷新权限 ，执行语句为：FLUSH PRIVILEGES;

10. 项目中输入刚刚修改的密码，再次测试连接，搞定

五，安装 Navicat for Mysql，下载

下载后，打开安装包，如提示文件已损坏或无法打开，请查看以下??文档或 损坏请查看此链接，打不开请查看此链接

五，本人使用next.js 框架来 使用egg.js

1. 全局安装egg.js的脚手架工具egg-init：
npm i egg-init -g

2. 在next.js 项目的根目录下新建 service，并cd service，用脚手架自动生成项目的基本结构
egg-init --type=simple

3. 安装插件
npm install

4. 启动
npm run dev

然后在浏览器中打开网址:http://127.0.0.1:7001/
如果在页面中显示hi.egg说明我们环境搭建完成。

5. 安装 egg-mysql
 
npm i egg-mysql --save 或 yarn add egg-mysql
安装完成可以到package.json中看一下

6. 插件配置，文件/server/config/plugin.js，下面配置

‘use strict‘;

//配置插件
exports.mysql = {
  enable: true,
  package: ‘egg-mysql‘
}

7. 数据库连接，打开/config/config.default.js文件，作下面的配置

‘use strict‘;

/**
 * @param {Egg.EggAppInfo} appInfo app info
 */
module.exports = appInfo => {
  /**
   * built-in config
   * @type {Egg.EggAppConfig}
   **/
  const config = exports = {};

  // use for cookie sign key, should change to your own and keep security
  config.keys = appInfo.name + ‘_1584348767004_9973‘;

  // add your middleware config here
  config.middleware = [];

  // add your user config here
  const userConfig = {
    // myAppName: ‘egg‘,
  };

  config.mysql = {
    client: {
      // host
      host: ‘localhost‘,
      // 端口号
      port: ‘3306‘,
      // 用户名
      user: ‘root‘,
      // 密码
      password: ‘321‘,
      // 数据库名
      database: ‘test‘
    },
    // 是否加载到 app 上，默认开启
    app: true,
    // 是否加载到 agent 上，默认关闭
    agent: false,
  };

  return {
    ...config,
    ...userConfig,
  };
};

五，遇到问题

以下问题有两种情况会提示错误

1. 密码输入错误，请输入正确密码

2. 因安装mysql默认为密码加密模式，需修改 为普通模式 (可查看 ??【四-7，8，9】题)

1. ERROR 25667 [-/127.0.0.1/-/0ms GET /] nodejs.ER_NOT_SUPPORTED_AUTH_MODEError: ER_NOT_SUPPORTED_AUTH_MODE: Client does not support authentication protocol requested by server; consider upgrading MySQL client

2. 2020-03-17 10:22:20,089 ERROR 26558 [-/127.0.0.1/-/0ms GET /] nodejs.ER_ACCESS_DENIED_ERRORError: ER_ACCESS_DENIED_ERROR: Access denied for user ‘root‘@‘localhost‘ (using password: YES)

    at Handshake.Sequence._packetToError (/Users/gaoqiaoxia/workSpace/blog/service/node_modules/_mysql@2.18.1@mysql/lib/protocol/sequences/Sequence.js:47:14)

    at Handshake.ErrorPacket (/Users/gaoqiaoxia/workSpace/blog/service/node_modules/_mysql@2.18.1@mysql/lib/protocol/sequences/Handshake.js:123:18)

    at Protocol._parsePacket (/Users/gaoqiaoxia/workSpace/blog/service/node_modules/_mysql@2.18.1@mysql/lib/protocol/Protocol.js:291:23)

    at Parser._parsePacket (/Users/gaoqiaoxia/workSpace/blog/service/node_modules/_mysql@2.18.1@mysql/lib/protocol/Parser.js:433:10)

    at Parser.write (/Users/gaoqiaoxia/workSpace/blog/service/node_modules/_mysql@2.18.1@mysql/lib/protocol/Parser.js:43:10)

    at Protocol.write (/Users/gaoqiaoxia/workSpace/blog/service/node_modules/_mysql@2.18.1@mysql/lib/protocol/Protocol.js:38:16)

    at Socket.<anonymous> (/Users/gaoqiaoxia/workSpace/blog/service/node_modules/_mysql@2.18.1@mysql/lib/Connection.js:88:28)

    at Socket.<anonymous> (/Users/gaoqiaoxia/workSpace/blog/service/node_modules/_mysql@2.18.1@mysql/lib/Connection.js:526:10)

    at Socket.emit (events.js:305:20)

    at addChunk (_stream_readable.js:341:12)

    --------------------

    at Protocol._enqueue (/Users/gaoqiaoxia/workSpace/blog/service/node_modules/_mysql@2.18.1@mysql/lib/protocol/Protocol.js:144:48)

    at Protocol.handshake (/Users/gaoqiaoxia/workSpace/blog/service/node_modules/_mysql@2.18.1@mysql/lib/protocol/Protocol.js:51:23)

    at PoolConnection.connect (/Users/gaoqiaoxia/workSpace/blog/service/node_modules/_mysql@2.18.1@mysql/lib/Connection.js:116:18)

    at Pool.getConnection (/Users/gaoqiaoxia/workSpace/blog/service/node_modules/_mysql@2.18.1@mysql/lib/Pool.js:48:16)

    at /Users/gaoqiaoxia/workSpace/blog/service/node_modules/_pify@2.3.0@pify/index.js:29:7

    at new Promise (<anonymous>)

    at Pool.<anonymous> (/Users/gaoqiaoxia/workSpace/blog/service/node_modules/_pify@2.3.0@pify/index.js:12:10)

    at Pool.ret [as getConnection] (/Users/gaoqiaoxia/workSpace/blog/service/node_modules/_pify@2.3.0@pify/index.js:56:34)

    at Pool.query (/Users/gaoqiaoxia/workSpace/blog/service/node_modules/_mysql@2.18.1@mysql/lib/Pool.js:202:8)

    at /Users/gaoqiaoxia/workSpace/blog/service/node_modules/_pify@2.3.0@pify/index.js:29:7

    sql: select now() as currentTime;

code: "ER_ACCESS_DENIED_ERROR"

errno: 1045

sqlMessage: "Access denied for user ‘root‘@‘localhost‘ (using password: YES)"

sqlState: "28000"

fatal: true

name: "ER_ACCESS_DENIED_ERRORError"

pid: 26558

hostname: MacBook-Pro.local

3. 2020-03-17 10:22:20,115 ERROR 26529 nodejs.AppWorkerDiedError: [master] app_worker#3:26558 died (code: 0, signal: null, suicide: false, state: dead), current workers: []

    at Master.onAppExit (/Users/gaoqiaoxia/workSpace/blog/service/node_modules/_egg-cluster@1.26.0@egg-cluster/lib/master.js:510:21)

    at Master.emit (events.js:305:20)

    at Messenger.sendToMaster (/Users/gaoqiaoxia/workSpace/blog/service/node_modules/_egg-cluster@1.26.0@egg-cluster/lib/utils/messenger.js:137:17)

    at Messenger.send (/Users/gaoqiaoxia/workSpace/blog/service/node_modules/_egg-cluster@1.26.0@egg-cluster/lib/utils/messenger.js:102:12)

    at EventEmitter.<anonymous> (/Users/gaoqiaoxia/workSpace/blog/service/node_modules/_egg-cluster@1.26.0@egg-cluster/lib/master.js:353:22)

    at EventEmitter.emit (events.js:317:22)

    at ChildProcess.<anonymous> (internal/cluster/master.js:192:13)

    at Object.onceWrapper (events.js:412:26)

    at ChildProcess.emit (events.js:305:20)

    at Process.ChildProcess._handle.onexit (internal/child_process.js:275:12)

name: "AppWorkerDiedError"

pid: 26529

hostname: MacBook-Pro.local

egg.js 使用 mysql 总结

原文：https://www.cnblogs.com/gqx-html/p/12509532.html