CentOS 7 安装MySQL8

安装

下载Linux对应的MySQL https://dev.mysql.com/downloads/mysql/node

CentOS选择Red Hat Enterprise Linuxmysql
在/usr/local/目录下新建目录mysqlsql
```
cd /usr/local/
 mkdir mysql
 cd mysql/
```

打开文件传输工具将下载的压缩包 mysql-8.0.17-1.el7.x86_64.rpm-bundle.tar 放到此目录解压 tar -xvf mysql-8.0.17-1.el7.x86_64.rpm-bundle.tar数据库

解压出来8个文件vim

mysql-community-client-8.0.17-1.el7.x86_64.rpm
 mysql-community-common-8.0.17-1.el7.x86_64.rpm
 mysql-community-devel-8.0.17-1.el7.x86_64.rpm
 mysql-community-embedded-compat-8.0.17-1.el7.x86_64.rpm
 mysql-community-libs-8.0.17-1.el7.x86_64.rpm
 mysql-community-libs-compat-8.0.17-1.el7.x86_64.rpm
 mysql-community-server-8.0.17-1.el7.x86_64.rpm
 mysql-community-test-8.0.17-1.el7.x86_64.rpm

检查是否有预装数据库mariadb rpm -qa | grep mariadb 及是否预装mysql运维

检测出来了就移除 rpm -e mariadb-libs-..... --nodeps 根据检查出来的名字输入tcp
安装ide
- 安装 common rpm -ivh mysql-community-common-8.0.17-1.el7.x86_64.rpm --nodeps --force工具
- 安装 libs rpm -ivh mysql-community-libs-8.0.17-1.el7.x86_64.rpm --nodeps --forceurl
- 安装 client rpm -ivh mysql-community-client-8.0.17-1.el7.x86_64.rpm --nodeps --force
- 安装 server rpm -ivh mysql-community-server-8.0.17-1.el7.x86_64.rpm --nodeps --force
- 查看已安装的包 rpm -qa | grep mysql
```
[root@izuf63okxpwhhlr3bu263dz mysql]# rpm -qa | grep mysql
  mysql-community-libs-8.0.17-1.el7.x86_64
  mysql-community-server-8.0.17-1.el7.x86_64
  mysql-community-common-8.0.17-1.el7.x86_64
  mysql-community-client-8.0.17-1.el7.x86_64
```

初始化

经过一下命令完成mysql初始化

mysqld --initialize

若是报以下错误信息：

mysqld:error while loading shared libraries: libaio.so.1: cannot open shared object file: No shch file or directory

则安装下 libaio.so.1 包

# 方案1
  yum install -y libaio

  # 方案2，若是方案1安装后，继续初始化mysql没成功，则执行该方案
  yum install -y libaio.so.1

受权服务

# 给mysql目录受权，通常不用操做，root用户拥有全部权限
  chown mysql:mysql /var/lib/mysql -R;

  # 启动mysql服务
  systemctl start mysqld.service;

  # 配置开机启动
  systemctl enable mysqld;

查看数据库默认密码 cat /var/log/mysqld.log | grep password

[root@izuf63okxpwhhlr3bu263dz mysql]# cat /var/log/mysqld.log | grep password
  2019-10-07T08:45:06.207436Z 5 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: gfn,!V/j7tlz

拿到查询出的密码进行数据库的登陆 mysql -u root -p gfn,!V/j7tlz
修改默认密码 alter user 'root'@'localhost' identified with mysql_native_password by 'root'; 修改后退出以修改后的密码从新登陆

受权远程访问

create user 'root'@'%' identified with mysql_native_password by '123456';
  grant all privileges on *.* to 'root'@'%' with grant option;
  flush privileges;

此时采用Navicat等可视化客户端可能没法链接，由于端口未对外开放

防火墙配置

# 查看防火墙状态
 systemctl status firewalld

 # 启动防火墙，防火墙启动后，除了22端口对外可以访问，其余端口军不能使用，因此须要添加
 systemctl start firewalld

 # 添加端口
 firewall-cmd --zone=public --add-port=80/tcp --permanent
 firewall-cmd --zone=public --add-port=443/tcp --permanent
 firewall-cmd --zone=public --add-port=3306/tcp --permanent

 # 从新加载
 firewall-cmd --reload

其余
- 查看MySQL配置文件
```
# 默认的配置文件为： /etc/my.cnf
  cat /etc/my.cnf
```
- 查看进程语句 ps -ef | grep mysql

大功告成

遗留问题

Linux下的MySQL数据库大小写敏感，因此SQL语句中的表名区分大小写

忽略大小写配置

$ vim /etc/my.cnf
  [mysqld]
  lower_case_table_names=1

可是在MySQL8 这样不行，网上有说要在初始化的时候设置才有效 --initialize --lower-case-table-names=1 可是我怎么试也不行，只要启动服务就报错

[root@izuf63okxpwhhlr3bu263dz mysql]# systemctl start mysqld.service;
    Job for mysqld.service failed because the control process exited with error code. See "systemctl status mysqld.service" and "journalctl -xe" for details.

折腾半天只好让它大小写敏感去吧，反正我也不是运维

卸载

关闭mysql服务

[root@izuf63okxpwhhlr3bu263dz mysql]# service mysqld stop
 Redirecting to /bin/systemctl stop  mysqld.service

查看安装的mysql

[root@izuf63okxpwhhlr3bu263dz mysql]# rpm -qa | grep -i mysql
 mysql-community-libs-8.0.17-1.el7.x86_64
 mysql-community-server-8.0.17-1.el7.x86_64
 mysql-community-common-8.0.17-1.el7.x86_64
 mysql-community-client-8.0.17-1.el7.x86_64

卸载列出来的全部mysql

rpm -ev mysql-community-......... --nodeps

删除mysql相关

find / -name mysql
 rm -rf /var/lib/mysql/
 ......

删除my.cnf

rm -rf /etc/my.cnf
检查卸载状况

rpm -qa|grep -i mysql

为空，大功告成