SQL 在 Where 子句中添加 Case 语句
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Add Case Statement in Where Clause
提问by CipherIS
I need to add a casestatement in a whereclause. I want it to run either statement below depending on the value of TermDate.
我需要case在where子句中添加一个语句。我希望它根据 TermDate 的值运行以下任一语句。
Select *
from myTable
where id = 12345
AND TermDate CASE
WHEN NULL THEN
AND getdate() BETWEEN StartDate AND DATEADD(dd, 30, StartDate)
ELSE
AND GETDATE < TermDate
END
回答by Mureinik
Why not just use an ORcondition?
为什么不直接使用OR条件？
SELECT *
FROM myTable
WHEN id = 12345
AND ((TermDate IS NULL AND
getdate() BETWEEN StartDate AND DATEADD(dd, 30, StartDate)) OR
GETDATE() < TermDate)
回答by Patrick Hofman
Since we all posted three exact answers, obviously too much, here a version that uses your case whenconstruction.
由于我们都发布了三个确切的答案，显然太多了，这里有一个使用您的case when构造的版本。
use this:
用这个：
select *
from myTable
where id = 12345
AND case
when TermDate IS NULL
AND getdate() BETWEEN StartDate AND DATEADD(dd, 30, StartDate)
then 1
when GETDATE < TermDate
then 1
else 0
end
= 1
回答by user2989408
You can accomplish this using ANDsand ORs. Try the following query.
您可以使用ANDs和来完成此操作ORs。尝试以下查询。
Select *
From myTable
where id = 12345
AND ((TermDate IS NULL
AND GETDATE() BETWEEN StartDate AND DATEADD(dd, 30, StartDate))
OR (GETDATE() < TermDate))
