SQL选择最大值

Question

我有一个查询象下面这样：

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 

答案是这样的：

Lname MAX(HOURS) 

Black 55 

从DB 55是最大小时正确的答案。但布莱克不工作55小时，这是另一名叫格兰特的人。似乎我有一个不相互关联的答案。我应该怎么做才能得到如下结果：

“Grant 55”作为答案。

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

我假设不同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 

您可能需要根据您的要求的条款来更改顺序。