问题描述：
Mysql8.0root再给其他给用户授予权限的时候报错
ERROR 1227 (42000): Access denied; you need (at least one of) the SYSTEM_USER privilege(s) for this operation

问题原因：

MySQL8版本中新增了一个system_user帐户类型，由于root用户没有SYSTEM_USER权限，导致错误出现。

解决方法：

为root添加权限

mysql> grant  all  privileges  on *.* to test@'%';
ERROR 1227 (42000): Access denied; you need (at least one of) the SYSTEM_USER privilege(s) for this operation
mysql> grant system_user on *.*  to 'root';
Query OK, 0 rows affected (0.04 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

mysql> grant  all  privileges  on *.* to test@'%';
Query OK, 0 rows affected (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)