select name, group_id from game group by group_id 报错

[阿萨德执行]

Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'cloud.game.name' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by
为什么会报错呢

给group_id 加上唯一性索性居然就不报错了
alter table game MODIFY group_id VARCHAR(55) UNIQUE not null;

[lhdz_bj]

其实，这个SQL没太大意义，因为分组是为了汇聚，select list中没人做任何汇聚，报错也提到了，这个主要和sql_mode参数有关。