如何在 WHERE 子句中引用别名? [英] How do I reference an alias in a WHERE clause?
本文介绍了如何在 WHERE 子句中引用别名?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
这是我的声明:
SELECT
C.Account,
(RTRIM(N.FIRST) + ' ' + RTRIM(LTRIM(N.MIDDLE)) + ' ' + RTRIM(LTRIM(N.LAST)) + ' ' + LTRIM(N.SUFFIX)) AS OwnerName,
DateAdd(dd, -1, C.ExpirationDate) as RealExpirationDate,
C.Description,
C.Type
FROM CARD as C
INNER JOIN NAME as N ON C.Account = N.Account
WHERE (RealExpirationDate BETWEEN @StartDate AND @EndDate)
AND C.Type IN(10,15,17,25)
我不断收到错误消息,指出 RealExpirationDate
是无效的列名.我如何引用该别名?
I keep getting an error saying that RealExpirationDate
is an invalid column name. How can I reference that alias?
推荐答案
你不能在上面的代码中,记住 WHERE
发生在 SELECT
之前,所以你会必须使用:
You can't in your code above, remember WHERE
happens before SELECT
, so you'd have to use:
WHERE DateAdd(dd, -1, C.ExpirationDate) BETWEEN @StartDate AND @EndDate
为这样的东西设置别名的最常见方法是一些内部视图/查询,如下所示:
The most common way to alias something like this would be some inner view / query like so:
SELECT
n.FooBar, --here we can use FooBar
t.BarFoo
FROM
MyTable t
INNER JOIN
(
SELECT
myTestCase as FooBar
From MyTable2
) n
这篇关于如何在 WHERE 子句中引用别名?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文