Hive中提示Expression Not In Group By Key的解决办法
问题出现的原因:
1.Hive不允许直接访问非group by字段;
2.对于非group by字段,可以用Hive的collect_set函数收集这些字段,返回一个数组;
3.使用数字下标,可以直接访问数组中的元素;
select publish_time,count(publish_time) as num from creationtime_out2 group by publish_time order by num desc;