CentOS7安装及卸载mysql

一、安装mysql源

1、创建mysql目录 /home/mysql

2、进入mysql目录 cd /home/mysql

3、下载mysql源安装包（可在http://dev.mysql.com/downloads/repo/yum/ 获取源安装包地址）

wget http://dev.mysql.com/get/mysql57-community-release-el7-11.noarch.rpm

[root@172 mysql]# wget http://dev.mysql.com/get/mysql57-community-release-el7-11.noarch.rpm

Length: 25680 (25K) [application/x-redhat-package-manager]

Saving to: ‘mysql57-community-release-el7-11.noarch.rpm’

100%[================  ======>] 25,680      --.-K/s   in 0.1s    

2017-12-13 09:49:40 (250 KB/s) - ‘mysql57-community-release-el7-11.noarch.rpm’ saved [25680/25680]

4、安装mysql源

 

[root@172 mysql]# yum localinstall mysql57-community-release-el7-11.noarch.rpm

Loaded plugins: fastestmirror, langpacks

.......

Total size: 31 k

Installed size: 31 k

Is this ok [y/d/N]: y

Downloading packages:

Running transaction check

Running transaction test

Transaction test succeeded

Running transaction

  Installing : mysql57-community-release-el7-11.noarch                                                                      1/1

  Verifying  : mysql57-community-release-el7-11.noarch                                                                      1/1

Installed:

  mysql57-community-release.noarch 0:el7-11                                                                                     

Complete!

5、检查mysql源安装情况

 [root@172 mysql]# yum repolist enabled | grep "mysql.*-community.*"

mysql-connectors-community/x86_64       MySQL Connectors Community           42

mysql-tools-community/x86_64            MySQL Tools Community                55

mysql57-community/x86_64                MySQL 5.7 Community Server          227

执行命令后返回上述结果表示mysql源安装成功。

二、安装mysql

1、安装mysql

 [root@172 mysql]# yum install mysql-community-server

Loaded plugins: fastestmirror, langpacks

Loading mirror speeds from cached hostfile

* base: centos.ustc.edu.cn

* extras: ftp.sjtu.edu.cn

........

Installed:

  mysql-community-server.x86_64 0:5.7.20-1.el7                                                                                 

Dependency Installed:

  mysql-community-client.x86_64 0:5.7.20-1.el7                   mysql-community-common.x86_64 0:5.7.20-1.el7                  

  mysql-community-libs.x86_64 0:5.7.20-1.el7                    

Complete!

---------------------

2、启动msyql

systemctl start mysqld

3、查看启动状态

 [root@172 mysql]# systemctl status mysqld

● mysqld.service - MySQL Server

   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)

   Active: active (running) since Thu 2017-12-14 06:02:51 EST; 2min 13s ago

     Docs: man:mysqld(8)

           http://dev.mysql.com/doc/refman/en/using-systemd.html

  Process: 9605 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=0/SUCCESS)

  Process: 9524 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)

Main PID: 9607 (mysqld)

   CGroup: /system.slice/mysqld.service

           └─9607 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid

Dec 14 06:02:33 *.*.*.* systemd[1]: Starting MySQL Server...

Dec 14 06:02:51 *.*.*.* systemd[1]: Started MySQL Server.

4、设置开机启动

systemctl enable mysqld

systemctl daemon-reload

三、配置mysql

1、修改密码策略

mysql5.7默认带有密码查检策略，密码默认策略要求：大小写字母、数字和特殊符号，并且长度不能少于8位。否则会提示ERROR 1819 (HY000): Your password does not satisfy the current policy requirements错误。

mysql的密码策略相关信息，可以在登录mysql后，通过命令show variables like ‘%password%’查看。

validate_password_policy：密码策略，默认为MEDIUM策略

validate_password_dictionary_file：密码策略文件，策略为STRONG才需要

validate_password_length：密码最少长度

validate_password_mixed_case_count：大小写字符长度，至少1个

validate_password_number_count ：数字至少1个

validate_password_special_char_count：特殊字符至少1个

mysql共有以下几种密码策略

 策略    检查规则

0 or LOW    Length

1 or MEDIUM    Length; numeric, lowercase/uppercase, and special characters

2 or STRONG    Length; numeric, lowercase/uppercase, and special characters; dictionary file

详情可参考：http://dev.mysql.com/doc/refman/5.7/en/validate-password-options-variables.html#sysvar_validate_password_policy

可通过修改/etc/my.cnf文件来达到修改密码策略目的，具体方式修改方式如下：

 # 选择0（LOW），1（MEDIUM），2（STRONG）其中一种，选择2需要提供密码字典文件

validate_password_policy=0

# 如果不需要密码策略，添加my.cnf文件中添加如下配置禁用即可：

validate_password = off

# 重新启动mysql服务使配置生效：

systemctl restart mysqld

2、修改root密码

mysql安装后，系统会自动初始化一个密码，通过如下命令查看：

 [root@172 mysql]# grep 'temporary password' /var/log/mysqld.log

2017-12-14T11:02:37.459592Z 1 [Note] A temporary password is generated for root@localhost: ju/,8f1;O!J8

# 密码为localhost:后的字符，本例为：ju/,8f1;O!J8

使用root和默认密码登录mysql

mysql -uroot -p，然后输入默认密码登录。

修改root密码，可通过以下两种方式：

 mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'your password';

mysql> set password for 'root'@'localhost'=password('your password');

3、添加远程访问权限

mysql> use mysql;  

mysql> update user set host = '%' where user = 'root';

mysql> select host, user from user;

mysql> flush privileges; 

到此已经全部安装完成，但是远程通过navicat mysql 依然无法连接到mysql上，出现10060错误，网上查了下是因为防火墙问题：防火墙开启见01，需要刷新

四、卸载mysql

1、关闭mysql服务systemctl stop mysqld

2、查看已经安装的mysql组件

 [root@172 ~]# rpm -qa | grep -i mysql

mysql-community-libs-compat-5.7.20-1.el7.x86_64

mysql-community-libs-5.7.20-1.el7.x86_64

mysql57-community-release-el7-11.noarch

mysql-community-client-5.7.20-1.el7.x86_64

mysql-community-server-5.7.20-1.el7.x86_64

mysql-community-common-5.7.20-1.el7.x86_64

 3、卸载已经安装过的组件

yum -y remove mysql-community-client-5.7.20-1.el7.x86_64

yum -y remove mysql-community-common-5.7.20-1.el7.x86_64

# 卸载comm时，libs-compat会跟随卸载，此步可不操作

yum -y remove mysql-community-libs-compat-5.7.20-1.el7.x86_64

yum -y remove mysql57-community-release-el7-11.noarch

# 卸载client时，server会跟随卸载，此步可不操作

yum -y remove mysql-community-server-5.7.20-1.el7.x86_64

4、删除mysql目录 

# whereis查找

[root@172 ~]# whereis mysql

mysql: /usr/share/mysql

# 删除残留

rm -rf /usr/share/mysql

# find查找

[root@172 ~]# find / -name mysql

/home/mysql

/etc/selinux/targeted/active/modules/100/mysql

/etc/selinux/targeted/tmp/modules/100/mysql

/var/lib/mysql

/var/lib/mysql/mysql

# 删除残留

rm -rf /home/mysql

rm -rf /etc/selinux/targeted/active/modules/100/mysql

rm -rf /etc/selinux/targeted/tmp/modules/100/mysql

rm -rf /var/lib/mysql

rm -rf /var/lib/mysql/mysql

# 删除配置文件

rm –rf /usr/my.cnf

rm -rf /root/.mysql_sercret  

5、确认卸载

rpm -qa | grep -i mysql