centos7安装mysql

5) 安装MySQL（centos7以下版本）

a) # lsb_release –a 查看Linux版本号 
b) 下载与当前Linux版本相匹配的MySQL版本 
由于MySQL网站Linux版本需要用Google的js 代码，无法下载，可以到如下镜像：http://mirror.bit.edu.cn/mysql/Downloads/MySQL-5.6/ 
MySQL-client-5.6.25-1.rhel5.x86_64 
MySQL-server-5.6.25-1.rhel5.x86_64 
c) 创建目录并上传　　mkdir -p usr/local/mysql 
d) 安装服务器端 
]# rpm -ivh MySQL-server-5.6.25-1.rhel5.x86_64.rpm 
测试是否成功可运行netstat看Mysql端口是否打开，如打开表示服务已经启动，安装成功。Mysql默认的端口是3306。 
e) 安装客户端 
]# rpm -ivh MySQL-client-5.6.25-1.rhel5.x86_64.rpm 
f) # service mysqld start 启动失败 
CentOS7的默认数据库已经不再是MySQL了，而是MariaDB

6) centos7中卸载MariaDB和MySQL

a) 查看centos版本 
]# cat /etc/redhat-release 
b) 卸载MariaDB 
查看当前安装的mariadb包：# rpm -qa | grep mariadb 
都卸载掉：# rpm -e –nodeps mariadb-libs-5.5.41-2.el7_0.x86_64 
c) 查看是否已经安装了MySQL 
]# rpm -qa | grep -i mysql 
d) 卸载MySQL 
]# rpm -e MySQL-client-5.6.25-1.rhel5.x86_64 
]# rpm -e MySQL-server-5.6.25-1.rhel5.x86_64 
无法正常卸载时 
]# yum remove MySQL-shared-advanced-5.6.22-.. 
e) 删除分散mysql文件 
]# find / -name mysql / # whereis mysql 
f) 删除配置文档 
]# rm -rf /etc/my.cnf 
g) 再次查找机器是否安装mysql 
]# rpm -qa|grep -i mysql

7) centos7中安装MySQL

a) 上传至/usr/local/rpm

MySQL-client-advanced-5.6.22-1.el7.x86_64.rpm 
MySQL-server-advanced-5.6.22-1.el7.x86_64.rpm

b) 创建MySQL用户及mysql目录

]#groupadd mysql 
]#useradd -r -g mysql mysql 
]# mkdir mysql/data/mysql 
]# mkdir mysql/data/test 
]# mkdir mysql/bin 
]#cd /usr/local/mysql 
]#sudo chown -R mysql . 
]#sudo chgrp -R mysql .

c) 安装rpm包

]# rpm –ivh MySQL-server-advanced-5.6.22-1.el7.x86_64.rpm

出现如下异常： 
FATAL ERROR: please install the following Perl modules before executing /usr/bin/mysql_install_db: 
Data::Dumper 
解决方案： 
]# yum install -y perl-Module-Install.noarch

原因： 
在centos7环境中没有找到离线安装的办法，只能在线安装，需要调整到可联网状态。虚拟机中的话，可以调整到nat模式下。

先卸载已安装失败的rpm包 
]# rpm –ev MySQL-server-advanced-5.6.22-1.el7.x86_64.rpm

再次安装rpm包 
]# rpm –ivh MySQL-server-advanced-5.6.22-1.el7.x86_64.rpm 
]# rpm –ivh MySQL-client-advanced-5.6.22-1.el7.x86_64.rpm

New default config file was created as /usr/my.cnf and 
will be used by default by the server when you start it. 
You may edit this file to change server settings

d) 初始化mysql配置文件

]# vi /usr/my.cnf 
basedir = /usr/local/mysql 
datadir = /usr/local/mysql/data 
port = 3306 
user = mysql

e) 启动MySQL

]# service mysql start

出现异常： 
ERROR! The server quit without updating PID file (/var/lib/mysql/master.pid).

启动日志中显示： 
[ERROR] Fatal error: Can’t open and lock privilege tables: Table ‘mysql.user’ doesn’t exist

解决方案： 
my.cnf中增加配置 
user = mysql

]# service mysql start

发生异常： 
Starting MySQL ERROR! Couldn’t find MySQL server (/usr/local/mysql/bin/mysqld_safe)

解决方案： 
]# cp /usr/bin/mysqld_safe /usr/local/mysql/bin/mysqld_safe

发生异常，又回到了第一个异常，回到了原点

分析： 
执行service mysql start这个的时候一定是发生了什么，那这个命令到底执行了什么？/etc/init.d/mysql脚本中显示，一切都只在usr/bin下面发生，my.cnf什么的都是瞎扯!整个mysql用户、目录都没用。 
]# cd /usr/bin 
]# service mysql start 
Starting MySQL…… SUCCESS!

f) 查看启动监听信息

]# netstat -lnp | grep -i mysql 
]# service mysql status

g) 首次登陆mysql

]# mysql -uroot –p 
直接回车之后，异常： 
ERROR 1045 (28000): Access denied for user ‘root’@’localhost’ (using password: NO)

解决方案： 
A RANDOM PASSWORD HAS BEEN SET FOR THE MySQL root USER ! 
You will find that password in ‘/root/.mysql_secret’. 
You must change that password on your first connect, 
no other statement but ‘SET PASSWORD’ will be accepted. 
See the manual for the semantics of the ‘password expired’ flag.

[root@master bin] # cat /root/.mysql_secret 
[root@master bin] # mysql -uroot –p 
mysql> set password for root@localhost = password(‘12’); 
mysql> show databases; 
mysql> use mysql; 
mysql> show tables; 
mysql> quit;