Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'img_id'

安装了mysql5.7，用group by 查询时抛出如下异常：

Expression #3 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'cslgdata.img_id' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by

原因：
      MySQL 5.7.5和up实现了对功能依赖的检测。如果启用了only_full_group_by SQL模式(在默认情况下是这样)，那么MySQL就会拒绝选择列表、条件或顺序列表引用的查询，这些查询将引用组中未命名的非聚合列，而不是在功能上依赖于它们。

解决方法:

1.登录MySQL

mysql -u root -p

2. 输入SHOW SESSION VARIABLES;

SHOW GLOBAL VARIABLES;

select @@sql_mode;

这时候你会看到session和global 的sql_mode的值都是一样的：
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

执行以下两个命令：

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

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

这两个命令，去掉 sql_mode 的 ONLY_FULL_GROUP_BY