0.下载mysql
wget http://dev.mysql.com/get/Downloads/MySQL-5.7/mysql-5.7.12-1.el6.x86_64.rpm-bundle.tar
1.查找是否安装
[root@mysql opt]# rpm -qa|grep mysql
查找是否安装mysql，结果如下
mysql-libs-5.1.73-3.el6_5.x86_64
[root@mysql opt]# rpm -e --nodeps mysql-libs-5.1.73-3.el6_5.x86_64
卸载mysql
[root@cmos1 mysql]# rpm -qa | grep mysql
mysql-libs-5.1.73-3.el6_5.x86_64
[root@cmos1 mysql]# rpm -e --nodeps mysql-libs-5.1.73-3.el6_5.x86_64
[root@cmos1 mysql]# rpm -qa | grep mysql
[root@cmos1 mysql]#
2. 解压
tar -xf mysql-5.7.12-1.el6.x86_64.rpm-bundle.tar
解压完成后由这么几个文件：
mysql-community-client-5.7.12-1.el6.x86_64.rpm
mysql-community-common-5.7.12-1.el6.x86_64.rpm
mysql-community-devel-5.7.12-1.el6.x86_64.rpm
mysql-community-embedded-5.7.12-1.el6.x86_64.rpm
mysql-community-embedded-devel-5.7.12-1.el6.x86_64.rpm
mysql-community-libs-5.7.12-1.el6.x86_64.rpm
mysql-community-libs-compat-5.7.12-1.el6.x86_64.rpm
mysql-community-server-5.7.12-1.el6.x86_64.rpm
mysql-community-test-5.7.12-1.el6.x86_64.rpm
3.开始安装
根据需要安装：
mysql-community-client-5.7.12-1.el6.x86_64.rpm
mysql-community-common-5.7.12-1.el6.x86_64.rpm
mysql-community-libs-5.7.12-1.el6.x86_64.rpm
mysql-community-server-5.7.12-1.el6.x86_64.rpm
mysql-community-devel-5.7.12-1.el6.x86_64.rpm
执行安装的示例：
rpm -ivh mysql-community-common-5.7.12-1.el6.x86_64.rpm
rpm -ivh mysql-community-libs-5.7.12-1.el6.x86_64.rpm
rpm -ivh mysql-community-devel-5.7.12-1.el6.x86_64.rpm
rpm -ivh mysql-community-client-5.7.12-1.el6.x86_64.rpm
rpm -ivh mysql-community-server-5.7.12-1.el6.x86_64.rpm
过程如下：
[root@cmos1 mysql]# rpm -ivh mysql-community-common-5.7.12-1.el6.x86_64.rpm
warning: mysql-community-common-5.7.12-1.el6.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY
Preparing... ########################################### [100%]
1:mysql-community-common ########################################### [100%]
[root@cmos1 mysql]# rpm -ivh mysql-community-libs-5.7.12-1.el6.x86_64.rpm
warning: mysql-community-libs-5.7.12-1.el6.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY
Preparing... ########################################### [100%]
1:mysql-community-libs ########################################### [100%]
[root@cmos1 mysql]# rpm -ivh mysql-community-devel-5.7.12-1.el6.x86_64.rpm
warning: mysql-community-devel-5.7.12-1.el6.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY
Preparing... ########################################### [100%]
1:mysql-community-devel ########################################### [100%]
[root@cmos1 mysql]# rpm -ivh mysql-community-client-5.7.12-1.el6.x86_64.rpm
warning: mysql-community-client-5.7.12-1.el6.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY
Preparing... ########################################### [100%]
1:mysql-community-client ########################################### [100%]
[root@cmos1 mysql]# rpm -ivh mysql-community-server-5.7.12-1.el6.x86_64.rpm
warning: mysql-community-server-5.7.12-1.el6.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY
Preparing... ########################################### [100%]
1:mysql-community-server ########################################### [100%]
[root@cmos1 mysql]#
===================================================
不要
4.启动mysql
service mysql start
或者使用如下命令：
/etc/init.d/mysql start
5. 此处没有设置密码，会报错
#1045 - Access denied for user 'root'@'localhost' (using password: NO)
解决方法是用安全方式登录，修改密码即可。
4.mysql安全方式启动:
mysqld_safe --user=mysql --skip-grant-tabes --skip-networking &
由于mysql5.7 中mysql.user 表中没有Password字段，用authentication_string 代替即可。
6. 至此mysql安装完成，可用客户端工具连接使用了.
===================================================
4.修改配置，跳过密码检测
[root@mysql MySQL]#vi /etc/my.cnf
修改配置文件
加入 skip-grant-tables
跳过密码检测
5.启动mysql
[root@mysql MySQL]#service mysqld start
启动mysql，过程如下：
[root@cmos1 mysql]# service mysqld start
Initializing MySQL database: [ OK ]
Installing validate password plugin: [ OK ]
Starting mysqld: [ OK ]
[root@cmos1 mysql]#
[root@mysql MySQL]#mysql –u root –p
登录，无需密码直接回车
过程如下：
[root@cmos1 mysql]# mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.12 MySQL Community Server (GPL)
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>
7.设置密码
mysql>use mysql;
选择数据库
mysql>update user set password_expired="N" where user="root";
设置密码失效为”N”
mysql>update user set authentication_string=password("123456") where user="root";
设置密码为”123456”
mysql>flush privileges;
刷新生效
mysql>quit;
退出
8.修改配置，恢复密码检测
[root@mysql MySQL]#vi /etc/my.cnf
修改配置
注释或删除 #skip-grant-tables
9.用密码登录
[root@mysql MySQL]#mysql –u root –p
用新密码登陆
10.修改密码
[root@mysql MySQL]#mysqladmin -u用户名 -p旧密码 password 新密码
[root@mysql MySQL]#mysqladmin -uroot –p123456 password “123-abcABC“
mysql>set password=password("123456");
11.查看现有的密码策略
mysql>show variables like 'val%';
validate_password_dictionary_file参数是指定密码验证的字典文件路径。
validate_password_length参数是密码的长度，这个参数由下面的公式生成
validate_password_number_count+ validate_password_special_char_count+ (2 * validate_password_mixed_case_count)
validate_password_mixed_case_count参数是密码中英文字符大小写的个数，当密码策略是MEDIUM或以上时生效。
validate_password_number_count参数是密码中至少含有的数字个数，当密码策略是MEDIUM或以上时生效。
validate_password_policy这个参数可以设为0、1、2，分别代表从低到高的密码强度，此参数的默认值为1，如果想将密码强度改若，则更改此参数为0。
validate_password_special_char_count参数是密码中非英文数字等特殊字符的个数，当密码策略是MEDIUM或以上时生效。
12.更改密码策略
mysql> set global validate_password_length=0; --更改密码长度
mysql> set global validate_password_policy=0; --更改密码策略为LOW
13.允许mysql远程访问
赋予任何主机访问数据的权限
mysql>grant all privileges on *.* to 'root'@'%'with grant option;
会报错：ERROR 1133 (42000): Can't find any matching row in the user table
其实如果事先在mysql.user表中存在root用户就正常了，或，将这句末尾加上identified by '密码' 也就正常了。如下面的命令行
mysql>grant all privileges on *.* to 'root'@'%'identified by '123456' with grant option;
14.设置编码，解决乱码问题
default-character-set=utf-8
通过在/etc/my.cnf中增加参数default-character-set=utf-8解决乱码问题
15.查看防火墙状态
systemctl status firewalld
临时关闭防火墙命令。重启电脑后，防火墙自动起来
systemctl stop firewalld
永久关闭防火墙命令。重启后，防火墙不会自动启动
systemctl disable firewalld
打开防火墙命令systemctl enable firewalld
16.mysql默认已是开机自启动