sql - 按生成的列分组

Question

我试图按分钟对数据进行分组，所以我尝试了这个查询:

SELECT FROM_UNIXTIME(
     unix_timestamp (time, 'yyyy-mm-dd hh:mm:ss'), 'yyyy-mm-dd hh:mm') as ts,
     count (*) as cnt 
     from toucher group by ts limit 10;

然后 hive 告诉我没有这样的列，

FAILED: SemanticException [Error 10004]: Line 1:134 Invalid table alias or column reference 'ts': (possible column names are: time, ip, username, code)

那么hive不支持吗？

Answer 1

SELECT FROM_UNIXTIME(unix_timestamp (time, 'yyyy-mm-dd hh:mm:ss'), 'yyyy-mm-dd hh:mm') as ts,
     count (*) as cnt 
from toucher 
group by FROM_UNIXTIME(unix_timestamp (time, 'yyyy-mm-dd hh:mm:ss'), 'yyyy-mm-dd hh:mm') limit 10;

或者更好

 select t.ts, count(*) from
(SELECT FROM_UNIXTIME(unix_timestamp (time, 'yyyy-mm-dd hh:mm:ss'), 'yyyy-mm-dd hh:mm') as ts             
    from toucher ) t
    group by t.ts limit 10;