SQL合併報表

Question

好的，我必須弄清楚如何僅向部門顯示病情最重的員工。如果一個部門有多名員工病假時間相同，則必須全部顯示。

第一個查詢給我按SickLeaveHours排序的部門中的每個人。 第二個查詢告訴我按部門分列的最高病假時間。

如何獲得頂部查詢以限制基於底部查詢的結果。

Select FirstName + ' ' + LastName as Name, (SickLeaveHours), Department.DepartmentID as DepartmentID, HumanResources.Department.Name 
FROM HumanResources.Employee, HumanResources.EmployeeDepartmentHistory, Person.Contact, HumanResources.Department 
Where Employee.EmployeeID=EmployeeDepartmentHistory.EmployeeID and Employee.ContactID=Contact.ContactID and EndDate is Null and HumanResources.Department.DepartmentID=EmployeeDepartmentHistory.DepartmentID 
Order by SickLeaveHours DESC 


Select DepartmentID, Max(SickLeaveHours) as 'Top Sick Leave Hours' 
From HumanResources.Employee, HumanResources.EmployeeDepartmentHistory 
Where EmployeeDepartmentHistory.EmployeeID=Employee.EmployeeID and EmployeeDepartmentHistory.EndDate is Null 
Group by DepartmentID 
Order by 'Top Sick Leave Hours' DESC 

Answer 1

一種方法是你的底查詢保存到一個臨時表，並基於「最佳病假時間」，從選擇它取決於你在做什麼其他的最佳解決方案就不一定了。

Answer 2

此窗口功能是否適合您？我沒有你的環境來測試這個以確保我的語法是完全正確的...

Select FirstName + ' ' + LastName as Name, 
MAX(SickLeaveHours) OVER (PARTITION BY Department.DepartmentID) as MaxSickLeaveHours,  
Department.DepartmentID as DepartmentID, HumanResources.Department.Name 
FROM HumanResources.Employee, HumanResources.EmployeeDepartmentHistory, Person.Contact, HumanResources.Department 
Where Employee.EmployeeID=EmployeeDepartmentHistory.EmployeeID and Employee.ContactID=Contact.ContactID and EndDate is Null and HumanResources.Department.DepartmentID=EmployeeDepartmentHistory.DepartmentID 
Order by SickLeaveHours DESC