Sql server SQL Server:AdventureWorks中男女员工的平均费率

我试图写一个查询，在AdventureWorks数据库中查找男女员工的平均工资率

我写了这篇文章（如下），但没有得到预期的结果：

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;

---

我正试图这样做，以便更好地了解函数的工作原理，只需按

性别进行分组，而不是按性别和比率进行分组：

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;

主要问题是，您正在按
rate
进行分组，这是您的平均值-不要这样做。此外，公共表表达式实际上并不填充任何函数，因此也可以将其删除：

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;

-在ANSI-92 SQL标准中（20多年前），旧样式的逗号分隔表列表样式被正确的ANSI
JOIN
语法所取代，不鼓励使用它