•  ERROR 1410 (42000): You are not allowed to create a user with GRANT

注释：host='%'代表任何客户机可以连接；host='localhost'仅本地连接；

用root登录,先重新设置root的权限，再设置test用户
use mysql;
update user set host='%' where user='root';
flush privileges;
grant all privileges on *.* to 'root'@'%'
flush privileges;
update set set host='%' where user='test';
grant all privileges on *.* to 'test'@'%';

• 删除批量表

select concat('drop table ', TABLE_NAME, ';') from information_schema.TABLES
where TABLE_SCHEMA = 'test' and TABLE_NAME LIKE 'A_%';

• 执行sql脚本后，show tables能查看数据，使用数据库连接工具查不到 执行sql记得切换用户为test，不用用root执行