從分組依據中排除列

Question

我有這樣的桌子

我目前的查詢

Select team, 
       stat_id, 
       max(statsval) as statsval 
from tbl 
group by team,
      statid

問題：我還需要選擇季節，顯然我需要將其添加到分組依據中，但是卻給了我無法更改分組依據的意外結果。因為我只需要按stat_id分組即可，只能按季節進行分組。 我需要獲取max（）記錄的季節。 有人可以幫我嗎？

我什至試過

Select team, 
       stat_id, 
       max (seasonid),
       max(statsval) as statsval 
from tbl 
group by team,
         statid

但這需要最長的季節，而並非完全正確的結果。

異常結果

+--------+--------+-------+---------+---------+
| season |  team  | round | stat_id | statval |
+--------+--------+-------+---------+---------+
|   2004 | 500146 |     3 |       1 |       5 |
|   2007 | 500147 |     1 |       1 |       4 |
+--------+--------+-------+---------+---------+

Answer 1

嘗試此操作並在完成分組后查找團隊ID：

;with tmp as 
(
  select team, 
         stat_id, 
         max(statsval) as statsval 
  from tbl 
  group by team,
           statid
) 
select tmp.*, 
       tbl.seasonid 
from tmp join tbl 
on tmp.team = tbl.team and  tmp.statid = tbl.stat_id; 

Answer 2

根據您的SQL Server版本，只能使用Window函數來完成此操作：

SELECT DISTINCT  team
    , stat_id
    , max(statsval) OVER (PARTITION BY team, stat_id) statsval
    , FIRST_VALUE(season_id) OVER (PARTITION BY team, stat_id ORDER BY  statsval DESC)
FROM tbl

Answer 3

使用Windows功能嘗試一下

Select distinct team, 
                statid, 
                max(statsval) OVER(PARTITION BY team,statid ORDER BY seasonid) as statid, 
                max(seasonid) OVER(PARTITION BY team,statid ORDER BY statid)
from tbl

Answer 4

如果需要完整的行，則可以簡單地使用相關的子查詢：

Select t.*
from tbl t
where t.season = (select max(t2.season) 
                  from tbl t2
                  where t2.team = t.team and t2.statsval = t.statsval
                 );

使用tbl(team, statsval, season)的索引，它的性能可能比其他選項好或更好。

一個性能較差（甚至帶有索引）的有趣方法是：

select top (1) with ties t.*
from tbl t
order by row_number() over (partition by team, statsval order by season desc);