mysql> show variables like "%proxy%"; #查看当前proxy是否开启，下图表示没有开启

mysql> set global check_proxy_users =on; #开启proxy 下图表示已开启
mysql> set global mysql_native_password_proxy_users = on;

mysql> exit
Bye #以上设置参数，对当前会话无效，需要退出后重新登录，或直接设置到my.cnf中去

mysql> create user will_dba; #类似组
mysql> create user 'will';
mysql> create user 'tom'; 
#密码就不设置了，如需设置密码后面加上identified by '123'

mysql> grant proxy on will_dba to will;
mysql> grant proxy on will_dba to tom;

mysql> grant select on *.* to will_dba;

mysql> show grants for will_dba;

mysql> show grants for will;

mysql> show grants for tom;

mysql> mysql> select * from mysql.proxies_priv;

[root@test-1 ~]# mysql -utom -p
mysql> show databases; #tom用户我们之前没有赋予权限，但这里可以查看
mysql> show tables;
mysql> select * from user\G