Question

我无法显示平均年龄和其他数据，我知道它应该显示多个字段，但它只显示一个字段。

SELECT EmpName, Age,AVG(Age)
FROM   Employee
WHERE  Age > ( SELECT AVG(Age)
               FROM   Employee
             )

Answer 1

您无法获得行和获得总体平均值。尝试加入他们：

SELECT e.EmpName
,      e.Age
,      a.AverageAge
FROM   Employee e
CROSS
JOIN   ( SELECT AVG(Age) AverageAge
         FROM   Employee
       ) a
WHERE  Age > AverageAge

Answer 2

SELECT EmpName, Age, (SELECT AVG(Age) FROM Employee) AverageAge
FROM Employee
WHERE Age > (SELECT AVG(Age) FROM Employee);

这里是正确的代码，我想你不能在SELECT旁边使用AVERAGE（Age），因为它不是退出列。

Answer 3

您可以使用HAVING子句来实现它

select name,age,avg(age)
from emp
group by name,age
having age > (select avg(age) from emp)

SQL AVG无法开始工作

3 个答案: