安装新本版的MySQL GROUP BY分组查询会出现错误提示如下：
[Err] 1055 - Expression #1 of ORDER BY clause is not in GROUP BY clause and contains nonaggregated column 'information_schema.PROFILING.SEQ' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_byMySQL 5.7.X的默认的sql_model值为(进入MySQL输入命令select @@global.sql_mode即可查看)：
ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION问题就出现在ONLY_FULL_GROUP_BY上，需要把该值去掉即可．
以Linux的MySQL 5.7.20为例说明修改方法：
打开mysql配置文件sudo vim /etc/mysql/mysql.conf.d/mysqld.cnf，然后在［mysqld］下添加如下一行：
sql_mode=STRICT_TRANS_TABLES,STRICT_ALL_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,TRADITIONAL,NO_AUTO_CREATE_USER
默认配置中没有sql_mode,自行添加此行，添加了此行配置就把ONLY_FULL_GROUP_BY默认的去掉了，保存之后重启MySQL即可（sudo service mysql restart）．
提示：如果进入MySQL命令行方式设置sql_model值，重启Mysql就又恢复默认值了，属于当前session范围的．所以最好直接修改配置文件，这样就会永久有效．