首先安装mysql

官网下载安装mysql-server

# wget http://dev.mysql.com/get/mysql-community-release-el7-5.noarch.rpm

# rpm -ivh mysql-community-release-el7-5.noarch.rpm

# yum install mysql-community-server

安装成功后重启mysql服务。

# service mysqld restart

进入mysql：

mysql -u root

设置密码（密码为：password）：

set password for 'root'@'localhost' =password('password');

登陆：

mysql -u root –p

创建mqtt数据库：

create database mqtt;

MySQL 设备在线状态表

创建mqtt_client表：

DROP TABLE IF EXISTS `mqtt_client`;
CREATE TABLE `mqtt_client` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `clientid` varchar(64) DEFAULT NULL,
  `state` varchar(3) DEFAULT NULL,
  `node` varchar(64) DEFAULT NULL,
  `online_at` datetime DEFAULT NULL,
  `offline_at` datetime DEFAULT NULL,
  `created` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  KEY `mqtt_client_idx` (`clientid`),
  UNIQUE KEY `mqtt_client_key` (`clientid`),
  INDEX topic_index(`id`, `clientid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8MB4;

MySQL 主题订阅表

创建mqtt_cub表：

DROP TABLE IF EXISTS `mqtt_sub`;
CREATE TABLE `mqtt_sub` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `clientid` varchar(64) DEFAULT NULL,
  `topic` varchar(180) DEFAULT NULL,
  `qos` tinyint(1) DEFAULT NULL,
  `created` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  KEY `mqtt_sub_idx` (`clientid`,`topic`,`qos`),
  UNIQUE KEY `mqtt_sub_key` (`clientid`,`topic`),
  INDEX topic_index(`id`, `topic`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8MB4;

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MySQL 消息存储表

创建mqtt_msg表：

DROP TABLE IF EXISTS `mqtt_msg`;
CREATE TABLE `mqtt_msg` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `msgid` varchar(64) DEFAULT NULL,
  `topic` varchar(180) NOT NULL,
  `sender` varchar(64) DEFAULT NULL,
  `node` varchar(64) DEFAULT NULL,
  `qos` tinyint(1) NOT NULL DEFAULT '0',
  `retain` tinyint(1) DEFAULT NULL,
  `payload` blob,
  `arrived` datetime NOT NULL,
  PRIMARY KEY (`id`),
  INDEX topic_index(`id`, `topic`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8MB4;

MySQL 保留消息表

创建mqtt_retain表：

DROP TABLE IF EXISTS `mqtt_retain`;
CREATE TABLE `mqtt_retain` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `topic` varchar(180) DEFAULT NULL,
  `msgid` varchar(64) DEFAULT NULL,
  `sender` varchar(64) DEFAULT NULL,
  `node` varchar(64) DEFAULT NULL,
  `qos` tinyint(1) DEFAULT NULL,
  `payload` blob,
  `arrived` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  UNIQUE KEY `mqtt_retain_key` (`topic`),
  INDEX topic_index(`id`, `topic`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8MB4;

MySQL 消息确认表

创建mqtt_acked表：

DROP TABLE IF EXISTS `mqtt_acked`;
CREATE TABLE `mqtt_acked` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `clientid` varchar(64) DEFAULT NULL,
  `topic` varchar(180) DEFAULT NULL,
  `mid` int(11) unsigned DEFAULT NULL,
  `created` timestamp NULL DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `mqtt_acked_key` (`clientid`,`topic`),
  INDEX topic_index(`id`, `topic`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8MB4;

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MySQL 数据存储

修改配置文件: emqx_backend_mysql.conf ?

配置 MySQL 服务器

支持配置多台 MySQL 服务器连接池:

## Mysql 服务器地址
backend.mysql.pool1.server = 127.0.0.1:3306

## Mysql 连接池大小
backend.mysql.pool1.pool_size = 8

## Mysql 用户名
backend.mysql.pool1.user = root

## Mysql 密码
backend.mysql.pool1.password = public

## Mysql 数据库名称
backend.mysql.pool1.database = mqtt

目录结构

不同安装方式得到的 EMQ X 其目录结构会有所不同，具体如下:

启用 MySQL 数据存储插件

./bin/emqx_ctl plugins load emqx_backend_mysql

或者在mqtt web页面启动

插件：

之后就可已在mysql数据库表中查看信息了