mysql8 sql_mode=only_full_group_

1. 登录mysql
2. select version(), @@sql_mode;
   结果中出现 only_full_group_by
3. 执行下列命令

set global sql_mode='STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION';

set session sql_mode='STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION';

4. 完成再次查询
   select version(), @@sql_mode;
5. 测试，执行group by语句
   SELECT * FROM scores GROUP BY cno HAVING degree=max(degree);
   成功显示结果