1

我有一个查询：

select substr(name,7,50) as location, points,sum(if (p1=r1,10,-10))as total from
dq.data 
group by points,location order by location,total desc

产生此数据：

FRANCE  |0|2|0|0|0|0|1  110.0    
FRANCE  |0|2|1|0|1|2|1  100.0    
FRANCE  |0|2|0|0|0|1|1  100.0    
FRANCE  |0|2|1|0|0|1|1  100.0    
FRANCE  |0|2|0|1|1|2|1  100.0    
FRANCE  |0|2|0|0|1|1|1  100.0
GERMANY |1|0|2|2|2|1|0  120.0    
GERMANY |1|0|2|2|2|0|0  110.0    
GERMANY |1|0|2|2|2|2|0  110.0    
GERMANY |1|0|2|2|2|0|2  110.0    
GERMANY |1|0|2|2|2|1|1  110.0

我想达到最高total和points每个相关的location。

我应该最终得到：

FRANCE  |0|2|0|0|0|0|1  110.0
GERMANY |1|0|2|2|2|1|0  120.0

我相信我需要使用子查询和MAX(total)，但我不能让它工作。在子查询中，我想选择points，但我不想按它分组，这显然是不允许的。

我该怎么做呢？

4

2 回答 2

3

你的直觉是正确的。您可以通过计算最大总数然后将其连接回原始数据来做到这一点：

select t.*
from (select substr(name,7,50) as location, points,sum(if (p1=r1,10,-10))as total
      from dq.data 
      group by points,location
     ) t join
     (select location, max(total) as maxtotal
      from (select substr(name,7,50) as location, points,sum(if (p1=r1,10,-10))as total
            from dq.data 
            group by points,location
           ) t
      group by location
     ) tsum
     on t.location = tsum.location and t.total = tsum.maxtotal

请注意，如果顶部有联系，此版本将返回重复项。

我对 google-biggquery 并不十分熟悉。如果它支持“with”语句，那么您可以通过执行以下操作来简化查询：

with t as (select substr(name,7,50) as location, points,sum(if (p1=r1,10,-10))as total
           from dq.data 
           group by points,location
          )
select t.*
from t join
     (select location, max(total) as maxtotal
      from t
      group by location
     ) tsum
     on t.location = tsum.location and t.total = tsum.maxtotal

如果它支持 windows 函数（例如 row_number()），那么您可以完全消除显式连接。

于 2012-06-21T15:33:15.750 回答
0

我最近遇到了类似的问题，解决了类似的问题： 

SELECT substr(name,7,50) as location, points,sum(if (p1=r1,10,-10))as total
FROM ( 
   SELECT * FROM dq.data ORDER BY location,sum(if (p1=r1,10,-10)) desc 
) tmp
GROUP BY points,location;

不确定它是否会工作，因为我的数据库是 MySQL，但它是一个很好的直观解决方案。按照您希望汇总行退出的方式对子查询进行排序。

于 2012-06-21T15:39:02.323 回答