用到GROUP BY 语句查询时报错com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'col_user_6.a.START_TIME' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by错误
解决方法 ：进入mysql 执行
set @@GLOBAL.sql_mode='';
set sql_mode ='STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION';
即把sql_mode 改成非only_full_group_by模式。
验证是否生效 SELECT @@GLOBAL.sql_mode 或 SELECT @@sql_mode
