我要做的是对同一列使用多个CASE WHEN条件。
下面是我的查询代码:
SELECT Url='',
p.ArtNo,
p.[Description],
p.Specification,
CASE
WHEN 1 = 1 or 1 = 1
THEN 1
ELSE 0
END as Qty,
p.NetPrice,
[Status] = 0
FROM Product p (NOLOCK)
然而，我想做的是对同一列“qty”使用多个WHEN。
如下代码所示:
IF
// CODE
ELSE IF
// CODE
ELSE IF
// CODE
ELSE
// CODE
当前回答
当有多种情况时，你可以使用下面的例子。
SELECT
id,stud_name,
CASE
WHEN marks <= 40 THEN 'Bad'
WHEN (marks >= 40 AND
marks <= 100) THEN 'good'
ELSE 'best'
END AS Grade
FROM Result
其他回答
只要用这个，当他们是类的时候，你必须用更多。
SELECT Url='',
p.ArtNo,
p.[Description],
p.Specification,
CASE
WHEN 1 = 1 or 1 = 1
THEN 1
WHEN 2 = 2
THEN 2
WHEN 3 = 3
THEN 3
ELSE 0
END as Qty,
p.NetPrice,
[Status] = 0
FROM Product p (NOLOCK)
综合所有条件
select a.* from tbl_Company a
where a.Company_ID NOT IN (1,2)
AND (
(0 =
CASE WHEN (@Fromdate = '' or @Todate='')
THEN 0
ELSE 1
END
) -- if 0=0 true , if 0=1 fails (filter only when the fromdate and todate is present)
OR
(a.Created_Date between @Fromdate and @Todate )
)
case when first_condition
then first_condition_result_true
else
case when second_condition
then second_condition_result_true
else
second_condition_result_false
end
end
end as qty
case表达式有三种格式。你可以用很多WHEN as做CASE;
CASE WHEN Col1 = 1 OR Col3 = 1 THEN 1
WHEN Col1 = 2 THEN 2
...
ELSE 0 END as Qty
或者一个简单的CASE表达式
CASE Col1 WHEN 1 THEN 11 WHEN 2 THEN 21 ELSE 13 END
或个案中个案作为;
CASE WHEN Col1 < 2 THEN
CASE Col2 WHEN 'X' THEN 10 ELSE 11 END
WHEN Col1 = 2 THEN 2
...
ELSE 0 END as Qty
这是对一条语句执行不同测试的有效方法
select
case colour_txt
when 'red' then 5
when 'green' then 4
when 'orange' then 3
else 0
end as Pass_Flag
这只适用于平等比较!
