yum 安装卸载mysql
以前做过yum安装卸载mysql的笔记，现在整理到网上，希望对需要的朋友有所帮助
1.下载YUM库
wget http://dev.mysql.com/get/mysql57-community-release-el7-10.noarch.rpm
或wget --no-check-certificate http://dev.mysql.com/get/mysql57-community-release-el7-10.noarch.rpm
2.安装YUM库
yum localinstall -y mysql57-community-release-el7-10.noarch.rpm
3.安装数据库
yum install -y mysql-community-server
4.启动MySQL服务
systemctl start mysqld.service
5.查找mysql安装时的临时密码
grep 'password' /var/log/mysqld.log |head -n 1
mysql -uroot -p回车
输入密码
6.修改密码，解决密码安全问题：
如何解决ERROR 1819 (HY000): Your password does not satisfy the current policy requirements错误？
解决：必须修改两个全局参数
set global validate_password_policy=0;
再修改密码的长度：set global validate_password_length=1;
修改密码：SET PASSWORD = PASSWORD('root');
7.添加远程登录用户
use mysql;
GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'root' WITH GRANT OPTION;
设置防火墙：
1）centos6
vi /etc/sysconfig/iptables
在-A RH-Firewall-1-INPUT -j REJECT –reject-with icmp-host-prohibited之前，添加
-A INPUT -m state --state NEW -m tcp -p tcp --dport 3306 -j ACCEPT
重启防火墙
service iptables restart
2）centos7
启动：# systemctl start firewalld
查看状态：# systemctl status firewalld 或者 firewall-cmd --state
停止：# systemctl stop firewalld
禁用：# systemctl disable firewalld
8.设置字符编码和区分大小写
SHOW VARIABLES LIKE '%char%';
修改mysql配置文件:vi /etc/my.cnf
[mysqld]
character-set-server=utf8
collation-server=utf8_general_ci
#区分大小写——-0:区分;1:不区分
lower_case_table_names=1
[client]
default-character-set=utf8
9.设置开机自启：
设置开机自动启动
# chkconfig mysqld on 或者 systemctl enable mysqld
# chkconfig --list | grep mysql
升级mysql-server
yum update mysql-server
mysql安装出现的错误：
-bash: mysql: command not found
解决：
# cd /usr/local/bin
# ln -fs /mysql安装路径/bin/mysql mysql
1、yum remove mysql mysql-server mysql-libs compat-mysql51
2、rm -rf /var/lib/mysql
3、rm /etc/my.cnf
查看是否还有mysql软件：
rpm -qa|grep mysql
如果存在的话，继续删除即可。
a）查看系统中是否以rpm包安装的mysql：
[root@localhost opt]# rpm -qa | grep -i mysql
MySQL-server-5.6.17-1.el6.i686
MySQL-client-5.6.17-1.el6.i686
b)卸载mysql
[root@localhost local]# rpm -e MySQL-server-5.6.17-1.el6.i686
[root@localhost local]# rpm -e MySQL-client-5.6.17-1.el6.i686
c)删除mysql服务
[root@localhost local]# chkconfig --list | grep -i mysql
[root@localhost local]# chkconfig --del mysql
d)删除分散mysql文件夹
[root@localhost local]# whereis mysql 或者 find / -name mysql
mysql: /usr/lib/mysql /usr/share/mysql
清空相关mysql的所有目录以及文件
rm -rf /usr/lib/mysql
rm -rf /usr/share/mysql
rm -rf /usr/my.cnf