mysql使用group by分组时出现错误ERROR 1055 (42000): Expression #1 of SELECT list is not in GROUP BY clause and

问题：

1055 - Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggregated column ‘cmp-31161029.t1.user_name’ which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by, Time: 0.000000s

查询sql_mode模式设置：

select @@global.sql_mode

结果：

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

解决方案：去除 ONLY_FULL_GROUP_BY重新 设置sql_mode

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’