安装mysql
参照python篇一键安装lnmp。安装完之后再按照下面修改密码，修改配置文件，否则安装的时候就修改配置文件会出错。
注意：这也是二进制安装mysql。另一种二进制安装容易出错，生产环境不要用rpm包安装，会出问题，测试过安装msyql不要改里面的字符类型，否则安装时候报错。等安装完后再修改
2、查看初始化的密码：
初始化mysql时生成的密码
初始化mysql
2018-11-27T07:28:39.407117Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2018-11-27T07:28:40.069251Z 0 [Warning] InnoDB: New log files created, LSN=45790
2018-11-27T07:28:40.181277Z 0 [Warning] InnoDB: Creating foreign key constraint system tables.
2018-11-27T07:28:40.194608Z 0 [Warning] No existing UUID has been found, so we assume that this is the first time that this server has been started. Generating a new UUID: 0fbb7543-f216-11e8-9f31-000c29c231f7.
2018-11-27T07:28:40.195834Z 0 [Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened.
2018-11-27T07:28:40.197256Z 1 [Note] A temporary password is generated for root@localhost: 8YuFFueq4P!o
8YuFFueq4P!o 就是密码
3、重置为复杂密码
3.1、配置免密登录 、重启mysql、登录mysql
在[mysqld]下面添加skip-grant-tables
[root@ecs-03 mysql]#service mysqld stop
[root@ecs-03 mysql]# vi /etc/my.cnf
[mysqld]
skip-grant-tables #跳过密码
重启数据库
[root@ecs-03 mysql]# systemctl restart mysqld
一条命令执行以上步骤如下
systemctl stop mysqld && sed -i '/mysqld/a skip-grant-tables' /etc/my.cnf && systemctl restart mysqld
登录数据库，下面直接回车 不用输入密码
[root@ecs-03 mysql]# mysql -u root -p
Enter password:
[root@ecs-02 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: 5.7.22 MySQL Community Server (GPL)
Copyright (c) 2000, 2018, 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>
3.2、 修改root数据库账号密码方式一（推荐）
修改当前用户为root
mysql> use mysql;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> select host, user from user;
+---------------+---------------+
| host | user |
+---------------+---------------+
| % | root |
| 192.168.0.% | root |
| 192.168.0.1.% | root |
| localhost | mysql.session |
| localhost | mysql.sys |
| localhost | root |
+---------------+---------------+
6 rows in set (0.00 sec)
mysql> update user set host='%' where user='root';
ERROR 1062 (23000): Duplicate entry '%-root' for key 'PRIMARY' #不用管，没有影响，直接下一步
mysql> flush privileges;
Query OK, 0 rows affected (0.02 sec)
重启数数据，否则不生效
systemctl restart mysqld #等操作完下面一起重启
授予root用户给其他用户授权的权限
update mysql.user set Grant_priv='Y' where User='root' and Host='%';
flush privileges;（刷新权限）
修改root密码、开启远程连接授权
mysql> flush privileges;
Query OK, 0 rows affected (0.02 sec)
mysql> grant all privileges on *.* TO 'root'@'%' identified by 'jenkins@123' with grant option;
Query OK, 0 rows affected, 1 warning (0.02 sec)
mysql>grant all on *.* to root@'localhost' identified by 'jenkins@123' with grant option;
mysql> alter user 'root'@'localhost' identified by 'jenkins@123';
mysql> flush privileges;
Mysql>exit
修改后把kip-grant-tables注释掉重启mysql
systemctl stop mysqld && sed -i 's/skip-grant-tables/#skip-grant-tables/g' /etc/my.cnf && systemctl restart mysqld
3.3、修改root数据库账号密码方式二
mysql> set password=password("youpassword");
mysql> alter user 'root'@'localhost' identified by '123456';
ERROR 1290 (HY000): The MySQL server is running with the --skip-grant-tables option so it cannot execute this statement
报错不用管，接着输入下面
mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.02 sec)
mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' identified by 'zihao@666';
Query OK, 0 rows affected, 1 warning (0.02 sec)
mysql>grant all on *.* to root@'localhost' identified by 'zihao@666';
mysql> alter user 'root'@'localhost' identified by 'zihao@666';
mysql> FLUSH PRIVILEGES;
修改后把kip-grant-tables注释掉重启mysql
systemctl stop mysqld && sed -i 's/skip-grant-tables/#skip-grant-tables/g' /etc/my.cnf && systemctl restart mysqld
3.4、用修改后的密码登录mysql
[root@bogon local]# mysql -u root -pzihao@666
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.22-log MySQL Community Server (GPL)
Copyright (c) 2000, 2018, 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>
4、重置为简单版密码
4.1、配置免密登录 、重启mysql、登录mysql
[root@ecs-03 mysql]# vi /etc/my.cnf
删掉：kip-grant-tables ，
添加：validate_password=off :可以修改成简单的密码
然后重启：
[mysqld]
validate_password=off
#skip-grant-tables
4.2、修改root数据库账号密码同上
5、修改字符为utf8mb4
安装完成后需要修改字符满足生产需求，之前公司就是总是出现乱码，后来改成utf8mb4问题解决
临时修改
mysql>show variables like 'character%';
mysql>set character_set_database=utf8mb4;
mysql>set character_set_server=utf8mb4;
永久修改
systemctl stop mysqld && sed -i -e 's/character-set-server = utf8/character-set-server = utf8mb4/g' -e '/client/ a\default-character-set = utf8mb4' -e '$a\default-character-set = utf8mb4' /etc/my.cnf && systemctl start mysqld
注意：character_set_database=utf8mb4 这句话不要写到配置文件里面，否则启动报错
要达到的效果
mysql> show variables like 'character%';
+--------------------------+----------------------------------+
| Variable_name | Value |
+--------------------------+----------------------------------+
| character_set_client | utf8mb4 |
| character_set_connection | utf8mb4 |
| character_set_database | utf8mb4 |
| character_set_filesystem | binary |
| character_set_results | utf8mb4 |
| character_set_server | utf8mb4 |
| character_set_system | utf8 |
| character_sets_dir | /usr/local/mysql/share/charsets/ |
+--------------------------+----------------------------------+
8 rows in set (0.01 sec)
