WHERE子句中的CASE？ [英] CASE in WHERE clause?

问题描述

  WHERE  
   -     
（b.is_ot_paycode = '  Y'  或 
   -   来自variableA  
 b.is_ot_paycode = '  Y'）
 < span class =code-keyword> AND  
   -   来自TABLE.PARAMETER1  
（b.is_wh_paycode = '  Y'  OR  
   -   来自variableA  
 b.is_wh_paycode = '  Y'）
   -   来自variableB  
  AND  b.is_ot_paycode = '  Y' 

如何在我的WHERE子句中创建一个CASE语句

当b.is_wh_paycode ='Y'（来自变量A）和

b.is_ot_paycode ='Y'（来自变量B）

我的b.is_wh_paycode （来自TABLE.PARAMETER1）总是等于'N'？



请和谢谢

解决方案

< blockquote>如果我理解你的问题，下面会澄清你的问题。

 选择 * 来自 TABLE1 其中（ case  
 当标志= '  Y'  然后  1  
  else   0  
  end ）>  0  

在上面的查询中，Flag列将为1或0作为值。我们只使用case语句来提取具有flag = Y的记录。



只是将case视为返回SQL类型的函数。在谓语中，你总是会这样做：


其中f（x）< operator>表达



案例是f（x）

运算符是>在这种情况下

快递是0



凡案例......结束> 0

访问这里......



http://stackoverflow.com/questions/7606019/sql-server-using-case-in-where-clause [ ^ ]



或



http://stackoverflow.com/questions/8785209/case-statement-within-where-clause-in-sql-server-2008 [ ^ ]

WHERE
-- from TABLE.PARAMETER1
(b.is_ot_paycode = 'Y' OR 
-- from variableA
b.is_ot_paycode = 'Y')
AND
-- from TABLE.PARAMETER1
  (b.is_wh_paycode = 'Y'  OR 
-- from variableA
  b.is_wh_paycode = 'Y') 
-- from variableB
AND b.is_ot_paycode = 'Y'

How can I create a CASE statement in my WHERE clause that
when b.is_wh_paycode = 'Y' (from variableA) and
b.is_ot_paycode = 'Y'(from variableB)
my b.is_wh_paycode (from TABLE.PARAMETER1) would always be equal to 'N'?

Please and Thank you

解决方案

If i understand your question correctly, below would clarify your question.

select * from TABLE1 where (case
          when  Flag='Y' then 1
          else 0
          end)   > 0

In the above query, Flag column will have either 1 or 0 as value. We are pulling only the records that has flag=Y using case statements.

just think of case as a function that returns a SQL type. In a predicate, you would always do

where f(x) <operator> expression

case is the f(x)
operator is > in this case
express is 0

where case .... end > 0

visit here...

http://stackoverflow.com/questions/7606019/sql-server-using-case-in-where-clause[^]

or

http://stackoverflow.com/questions/8785209/case-statement-within-where-clause-in-sql-server-2008[^]

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