SQL Query返回最大值数十年

Question

这是使用MYSQL 我的问题是以下内容。我有一个棒球数据库，在那个棒球数据库中有一个主表，列出了所有曾经玩过的球员。还有一个击球桌，可以跟踪每个球员的击球统计数据。我创造了一个将这两者结合在一起的观点;因此masterplusbatting表。 我现在想从棒球开始的每个十年中找到最高的人力资源击球手。这是我试过的。

select f.yearID, truncate(f.yearid/10,0) as decade,f.nameFirst, f.nameLast, f.HR 
    from (
    select yearID, max(HR) as HOMERS 
    from masterplusbatting group by yearID 
    )as x inner join masterplusbatting as f on f.yearID = x.yearId and f.HR = x.HOMERS 
    group by decade 

你可以看到，我截断，以便在yearID得到187, 188, 189等，而不是1897, 1885,。然后，我将这十年分组，认为这会使我每十年中达到最高水平，但它并没有返回正确的值。例如，它在2004年给了我48位HR的Adrian Beltre，但是大家都知道Barry Bonds在2001年达到了73人。任何人都可以给我一些建议吗？

Answer 1

SELECT 
    Lookup.DecadeID, 
    Data.* 
FROM 
(
    SELECT 
    truncate(yearid/10,0) as decadeID, 
    MAX(HR) as Homers 
    FROM 
    masterplusbatting 
    GROUP BY 
    truncate(yearid/10,0) 
) 
    AS lookup 
INNER JOIN 
    masterplusbatting AS data 
    ON data.yearid >= lookup.decadeID * 10 
    AND data.yearid < lookup.decadeID * 10 + 10 
    AND data.HR  = lookup.homers 

Editted为MySQL

Answer 2

您的查询似乎是由错误的东西聚合。在某个地方，我希望看到一个以玩家为基础的小组。

select truncate(mpb.yearid/10, 0) as decade, mpb.nameFirst, mpb.nameLast, sum(mpb.HR) as HRs 
from masterplusbatting mpb 
group by truncate(mpb.yearid/10, 0), mpb.nameFirst, mpb.nameLast 

这给出了每个十年的本垒打总数。现在，你想要的人最多。对于这一点，我会用row_number()功能和子查询：

select decade, nameFirst, nameLast, HRs 
from (select decade, nameFirst, nameLast, HRs, 
      row_number() over (partition by decade order by HRs desc) as seqnum 
     from (select truncate(mpb.yearid/10, 0) as decade, mpb.nameFirst, mpb.nameLast, sum(mpb.HR) as HRs 
      from masterplusbatting mpb 
      group by truncate(mpb.yearid/10, 0), mpb.nameFirst, mpb.nameLast 
      ) t 
    ) t 
where seqnum = 1 
order by 1 

在数据库如MySQL，你需要一个这样做第二个连接：

select t.* 
from (select truncate(mpb.yearid/10, 0) as decade, mpb.nameFirst, mpb.nameLast, sum(mpb.HR) as HRs 
     from masterplusbatting mpb 
     group by truncate(mpb.yearid/10, 0), mpb.nameFirst, mpb.nameLast 
    ) t join 
    (select decade, max(HRs) as maxHRs 
     from (select truncate(mpb.yearid/10, 0) as decade, mpb.nameFirst, mpb.nameLast, sum(mpb.HR) as HRs 
      from masterplusbatting mpb 
      group by truncate(mpb.yearid/10, 0), mpb.nameFirst, mpb.nameLast 
      ) t 
     group by decade 
    ) tsum 
    on t.decade = tsum.decade and t.HRs = tsum.maxHRs 
order by decade