如何通过计算结果过滤行

Question

下面的代码创建一个新列“ ZScore”

SELECT [Cardholder Name], [Debit Amount], ([Debit Amount] - AVG([Debit Amount]) OVER ()) / (STDEV([Debit Amount]) OVER ()) as [ZScore]
FROM ['Card Data']
ORDER BY [ZScore] DESC;

我想做的是仅显示ZScore> = 3的行。我尝试了以下操作，但一切似乎都出错了。

SELECT [Cardholder Name], [Debit Amount], ([Debit Amount] - AVG([Debit Amount]) OVER ()) / (STDEV([Debit Amount]) OVER ()) as [ZScore]
FROM ['PCard Output']
HAVING (([Debit Amount] - AVG([Debit Amount]) OVER ()) / (STDEV([Debit Amount]) OVER ())) > 3
ORDER BY [ZScore] DESC;

仅显示计算出的z得分> = 3的行的正确方法是什么？

Answer 1

只需使用子查询：

SELECT cd.*
FROM (SELECT [Cardholder Name], [Debit Amount], ([Debit Amount] - AVG([Debit Amount]) OVER ()) / (STDEV([Debit Amount]) OVER ()) as [ZScore]
      FROM ['Card Data']
     ) cd
WHERE ZScore > 3
ORDER BY [ZScore] DESC;