SQL服務器：AdventureWorks中

Question

男性和女性員工平均速率

我想編寫一個查詢找到AdventureWorks數據庫

我寫這個（下）男性和女性僱員的平均工資率，但我沒有得到期望的結果：

with sub as 
(
    select 
     emp.Gender, emp.VacationHours, pay.Rate 
    from 
     HumanResources.Employee emp, HumanResources.EmployeePayHistory pay 
    where 
     emp.BusinessEntityID = pay.BusinessEntityID 
) 
select 
    sub.Gender, 
    avg(sub.VacationHours) as vac_hours, 
    avg(sub.Rate) as rate 
from 
    sub 
group by 
    sub.Gender, Rate; 

我試圖做到這一點，所以我可以更好地瞭解函數是如何工作

Answer 1

只需按gender單純 - 不是性別和速度：

with sub AS 
(
    select 
     emp.Gender, emp.VacationHours, pay.Rate 
    from 
     HumanResources.Employee emp 
    inner join 
     HumanResources.EmployeePayHistory pay on emp.BusinessEntityID = pay.BusinessEntityID 
) 
select 
    sub.Gender, 
    avg(sub.VacationHours) as vac_hours, 
    avg(sub.Rate) as rate 
from 
    sub 
group by 
    sub.Gender; 

Answer 2

主要問題是你正在分組rate這就是你平均 - 不這樣做。此外，公共表表達式並沒有真正填補任何功能，因此它可以去除過多：

select 
    Gender, 
    avg(VacationHours) as vac_hours, 
    avg(Rate) as rate 
from 
    HumanResources.Employee emp 
join 
    HumanResources.EmployeePayHistory pay on emp.BusinessEntityID = pay.BusinessEntityID 
group by 
    Gender;