SQL選擇最大值

Question

我有一個查詢象下面這樣：

Select Lname, MAX(HOURS)  
From (Select E.LName, SUM(Hours) as HOURS  
From WORKS_ON W  
    JOin EMPLOYEE E on E.SSN=W.ESSN  
Group by E.SSN) as hours 

答案是這樣的：

Lname MAX(HOURS) 

Black 55 

從DB 55是最大小時正確的答案。但布萊克不工作55小時，這是另一名叫格蘭特的人。似乎我有一個不相互關聯的答案。我應該怎麼做才能得到如下結果：

「Grant 55」作爲答案。

Answer 1

Select E.LName, SUM(Hours) as HOURS  
From WORKS_ON W  
    JOin EMPLOYEE E on E.SSN=W.ESSN  
group by E.LName 
ORDER BY HOURS desc 
limit 1 

Answer 2

我假設不同LName的，SSN在E表

Select 
    E.LName 
    ,SUM(Hours) as HOURS  
From 
    WORKS_ON W  
    JOin EMPLOYEE E on E.SSN=W.ESSN 
GROUP BY 
    E.SSN 
    ,E.LName 
ORDER BY 
    E.LName 

您可能需要根據您的要求的條款來更改順序。