Question

我试图按特定日期过滤结果，但是当我使用下面的代码时，我只得到CloseDate与当前日期匹配的结果。当CloseDate为Null时，它不包括ResolvedDate的结果。我尝试过：

(CASE WHEN (Closedate IS Null) then ResolvedDate, ELSE CloseDate END) AS FinalDate

然后它说：

 "column FinalDate does not exist"

我可以用其他任何方式吗？

这是迄今为止的代码。感谢您的帮助。

SELECT
id,
(CASE WHEN (Closedate IS Null) then ResolvedDate, ELSE CloseDate END),
FROM cases
WHERE (EXTRACT (month FROM Closedate) = EXTRACT(month FROM current_date))
AND  ( EXTRACT(day from Closedate) = EXTRACT(day FROM current_date))

Answer 1

假设你想要匹配年份：

SELECT id, COALESCE(Closedate, ResolvedDate) AS cdate
FROM   cases
WHERE  date_trunc('day', COALESCE(Closedate, ResolvedDate))
     = date_trunc('day', now())

每个文档：COALESCE，date_trunc()

如果你想忽略这一年：

WHERE  to_char(COALESCE(Closedate, ResolvedDate), 'MMDD')
     = to_char(now(), 'MMDD')

更多内容：
How do you do date math that ignores the year?

Answer 2

您应该使用COALESCE函数http://www.postgresql.org/docs/current/static/functions-conditional.html

试试这个：

SELECT
  id,
  COALESCE(CloseDate, ResolvedDate) AS FinalDate
FROM
  cases
WHERE
  (EXTRACT (month FROM COALESCE(CloseDate, ResolvedDate)) = EXTRACT(month FROM current_date)) AND
  (EXTRACT (day from COALESCE(CloseDate, ResolvedDate)) = EXTRACT(day FROM current_date))

应该这样做......

postgresql案例的日期和按日期排序

2 个答案: