根据平均值过滤和计算

Question

我的问题是：列出薪水大于平均工资的所有员工，并显示差异有多大。

SELECT staffname 
FROM   staff 
WHERE  salary >= (SELECT Avg(salary) 
                  FROM   staff) 
        AND (SELECT Max(salary) AS Max_Salary, 
                   Avg(salary) AS Avg_Salary 
            FROM   staff 
            WHERE  salary = max_salary - avg_salary) 

大于平均工资的薪水很快就会出来，但我无法证明差异有多大。

Answer 1

SELECT staffname, staff.salary - avg.salary
FROM staff, (SELECT AVG(salary) salary FROM staff) avg
WHERE staff.salary > avg.salary

Answer 2

Select Count(*), (Select Avg(Salary) From Staff)
From Staff
Where Salary > (Select Avg(Salary) From Staff);