select user,host from mysql.user;
SELECT * FROM mysql.user WHERE user='root';
set global validate_password_policy=0;
set global validate_password_length=6;
CREATE USER 'guest'@'%' IDENTIFIED BY 'guest123456';
ALTER USER 'guest'@'%' IDENTIFIED BY 'guest123'
(其中*.*表示配置的“数据库名.表名”,此处表示所有数据库皆可被读取到。另外,指定只读某个数据库方式,例如mydb数据库:mydb.*)
GRANT SELECT ON *.* TO 'guest'@'%';
FLUSH PRIVILEGES;
查看所有参数
SHOW VARIABLES LIKE 'validate_password%';

修改语句:
set global validate_password_mixed_case_count=1;
set global validate_password_number_count=1;
set global validate_password_special_char_count=1;