SQL Query返回最大值數十年

Question

這是使用MYSQL 我的問題是以下內容。我有一個棒球數據庫，在那個棒球數據庫中有一個主表，列出了所有曾經玩過的球員。還有一個擊球桌，可以跟蹤每個球員的擊球統計數據。我創造了一個將這兩者結合在一起的觀點;因此masterplusbatting表。 我現在想從棒球開始的每個十年中找到最高的人力資源擊球手。這是我試過的。

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，我截斷，以便在yearID得到187, 188, 189等，而不是1897, 1885,。然後，我將這十年分組，認爲這會使我每十年中達到最高水平，但它並沒有返回正確的值。例如，它在2004年給了我48位HR的Adrian Beltre，但是大家都知道Barry Bonds在2001年達到了73人。任何人都可以給我一些建議嗎？

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爲MySQL

Answer 2

您的查詢似乎是由錯誤的東西聚合。在某個地方，我希望看到一個以玩家爲基礎的小組。

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 

這給出了每個十年的本壘打總數。現在，你想要的人最多。對於這一點，我會用row_number()功能和子查詢：

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 

在數據庫如MySQL，你需要一個這樣做第二個連接：

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