SQL语言 - 有两种方法可以写平均值吗？

Question

问题是＆＃34;列出所有付款大于平均付款额的两倍＆＃34;

SELECT AVG(amount)
FROM Payments
WHERE amount > AVG(amount)*2;

Answer 1

您需要子查询来计算总体平均金额：

SELECT * 
FROM Payments 
WHERE amount > (SELECT AVG(amount)*2 FROM Payments)

Answer 2

您可以将平均值放在变量

中

Declare @average int
Select @average = ...
Select * from ... Where x>= @average

Answer 3

此查询可能对您有所帮助：

SELECT * FROM `Payments` WHERE amount > ((select avg(amount) from `Payments`)*2)