mysql5.7 安装
官方地址：
https://dev.mysql.com/downloads/mysql/
安装mysql源
#yum localinstall mysql57-community-release-el7-{version-number}.noarch.rpm
$ yum localinstall http://dev.mysql.com/get/mysql57-community-release-el7-7.noarch.rpm
安装mysql
$ yum install mysql-community-server
安装mysql的开发包
$ yum install mysql-community-devel
查看mysql状态
systemctl status mysqld.service
● mysqld.service - MySQL Server
Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
Active: inactive (dead)
Docs: man:mysqld(8)
http://dev.mysql.com/doc/refman/en/using-systemd.html
启动MySQL
$ systemctl start mysqld.service
● mysqld.service - MySQL Server
Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
Active: active (running) since Mon 2018-04-16 01:47:59 UTC; 5s ago
Docs: man:mysqld(8)
http://dev.mysql.com/doc/refman/en/using-systemd.html
Process: 17327 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=0/SUCCESS)
Process: 17256 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
Main PID: 17329 (mysqld)
CGroup: /docker/1391c87e0974ca70633404d8eb5ef54f6d2e443d84db634a224cb67fb26cc83d/system.slice/mysqld.service
└─17329 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/my...
‣ 17329 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/my...
Apr 16 01:47:56 1391c87e0974 systemd[1]: Starting MySQL Server...
Apr 16 01:47:59 1391c87e0974 systemd[1]: Started MySQL Server.
获取mysql默认生成的密码
$ grep 'temporary password' /var/log/mysqld.log
2018-04-16T01:47:56.993269Z 1 [Note] A temporary password is generated for root@localhost: 2xbJEddd7f;3
修改密码
$ mysql -u root -p
Enter password:输入上面的密码，进入mysql
修改
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'root';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
这个密码一定要足够复杂，不然会提示密码不合法
这个其实与validate_password_policy的值有关。
validate_password_policy有以下取值：
PolicyTests Performed
0 or LOWLength
1 or MEDIUMLength; numeric, lowercase/uppercase, and special characters
2 or STRONGLength; numeric, lowercase/uppercase, and special characters; dictionary file
默认是1，即MEDIUM，所以刚开始设置的密码必须符合长度，且必须含有数字，小写或大写字母，特殊字符。
有时候，只是为了自己测试，不想密码设置得那么复杂，譬如说，我只想设置root的密码为123456。
必须修改两个全局参数：
首先，修改validate_password_policy参数的值
mysql> set global validate_password_policy=0;
Query OK, 0 rows affected (0.00 sec)
这样，判断密码的标准就基于密码的长度了。这个由validate_password_length参数来决定
mysql> select @@validate_password_length;
+----------------------------+
| @@validate_password_length |
+----------------------------+
| 8 |
+----------------------------+
1 row in set (0.00 sec)
validate_password_length参数默认为8，它有最小值的限制，最小值为：
validate_password_number_count
+ validate_password_special_char_count
+ (2 * validate_password_mixed_case_count)
其中，validate_password_number_count指定了密码中数据的长度，validate_password_special_char_count指定了密码中特殊字符的长度，validate_password_mixed_case_count指定了密码中大小字母的长度
这些参数，默认值均为1，所以validate_password_length最小值为4，如果你显性指定validate_password_length的值小于4，尽管不会报错，但validate_password_length的值将设为4
如：
mysql> set global validate_password_length=1;
Query OK, 0 rows affected (0.00 sec)
mysql> select @@validate_password_length;
+----------------------------+
| @@validate_password_length |
+----------------------------+
| 4 |
+----------------------------+
1 row in set (0.00 sec)
如果修改了validate_password_number_count，validate_password_special_char_count，validate_password_mixed_case_count中任何一个值，则validate_password_length将进行动态修改。
以上验证的前提是validate_password插件必须已经安装，MySQL5.7是默认安装的
mysql允许远程访问：
给192.168.1.100 权限访问
mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'192.168.1.100' IDENTIFIED BY 'root用户的密码' WITH GRANT OPTION;
给任意IP 访问
mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'root用户的密码' WITH GRANT OPTION;
修改生效
mysql> flush privileges;