Question

这是我的陈述：

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)

我一直收到错误消息，指出RealExpirationDate是无效的列名。我该如何引用该别名？

Answer 1

您不能在上面的代码中，记住WHERE之前发生SELECT，所以您必须使用：

WHERE DateAdd(dd, -1, C.ExpirationDate) BETWEEN @StartDate AND @EndDate

最常见的别名方法是内部视图/查询，如下所示：

SELECT
  n.FooBar,  --here we can use FooBar
  t.BarFoo
FROM
  MyTable t
INNER JOIN
(
 SELECT
   myTestCase as FooBar
 From MyTable2
) n

Answer 2

在这种情况下，您实际上不应该尝试重用别名。它不是可以攻击的（不能在ExpirationDate上进行范围搜索。）

只需使用

WHERE C.ExpirationDate 
  BETWEEN DateAdd(dd, 1, @StartDate)  AND DateAdd(dd, 1, @EndDate)

Answer 3

您无法引用别名。您的查询必须是

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 (DateAdd(dd, -1, C.ExpirationDate) BETWEEN @StartDate AND @EndDate)
  AND C.Type IN(10,15,17,25)

Answer 4

在SQL Server中，您可以使用CROSS APPLY执行此操作。这比subselect简单，但我不确定是否存在性能差异。

SELECT 
  C.Account, 
  (RTRIM(N.FIRST) + ' ' + RTRIM(LTRIM(N.MIDDLE)) + ' ' + RTRIM(LTRIM(N.LAST)) + ' ' + LTRIM(N.SUFFIX)) AS OwnerName,
  RealExpirationDate, 
  C.Description, 
  C.Type
FROM CARD as C
  INNER JOIN NAME as N ON C.Account = N.Account
CROSS APPLY
  (SELECT DateAdd(dd, -1, C.ExpirationDate)) CrossA(RealExpirationDate)
WHERE (RealExpirationDate BETWEEN @StartDate AND @EndDate)
  AND C.Type IN(10,15,17,25)

Answer 5

使用：

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 (DateAdd(dd, -1, C.ExpirationDate) BETWEEN @StartDate AND @EndDate)
AND C.Type IN(10,15,17,25)

或

SELECT * from (
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 C.Type IN(10,15,17,25)
) t
WHERE RealExpirationDate BETWEEN @StartDate AND @EndDate

如何在WHERE子句中引用别名？

5 个答案: