内容：MySQL 中授权语法及相关内容。
授权访问数据库
How To Create a New User and Grant Permissions in MySQL
MySQL :: MySQL 5.7 Reference Manual :: 13.7.1.4 GRANT Statement
-- MySQL 5.7, MySQL 8.0 GRANT ALL PRIVILEGES ON `test_db`.* TO 'testuser'@'%';
允许用户建库，但是仅能访问自己的数据库
Let MySQL users create databases, but allow access to only their own databases
通过前缀匹配的方式进行权限限制：
GRANT ALL PRIVILEGES ON `testuser_%`.* TO 'testuser'@'%';
授予只读权限：
- GRANT SELECT ON *.* TO ‘k4nzdroid-ro’@’%’;
- FLUSH PRIVILEGES;
授权操作（MySQL 5.7）
MySQL :: MySQL 5.7 Reference Manual :: 13.7.5.21 SHOW GRANTS Statement
how to add super privileges to mysql database? – Stack Overflow
SHOW GRANTS [FOR user] -- 授予 SUPER 权限 mysql> GRANT SUPER ON *.* TO user@'localhost' IDENTIFIED BY 'password'; mysql> FLUSH PRIVILEGES;