如何在选择子句中执行布尔运算 [英] How to do a boolean operation in a select clause

问题描述

你好，

我想做一个选择语句，它返回一个布尔值

例如

 选择名字，姓氏(收入>  30000 )         


我该如何在语法上用mssql做到这一点?如果我按上述方法进行操作，则会收到语法错误
解决方案
 
，您可以使用case statement.



试试这个查询.. 



 选择名字，姓氏((大小写  30000  '  true'  else  ' span>  false' 结束) as 富人来自 tbl_person 
 



这将返回true或false作为varchar.如果要在布尔值中分别替换为1和0.



 选择名，姓((大小写  30000   1  其他  0  结束) as  richperson 来自 tbl_person 
 

希望对您有所帮助.
 
 
尝试:
  SELECT 名字，姓氏，何时收入>  30000   THEN   1   0   END   AS  richperson  FROM  tbl_person 
 
 
 
首先，SQL Server没有布尔数据类型.最接近的等效项是bit.因此，这意味着根据您的需要，您可能必须在使用代码之前翻译"代码中的返回值.



Karthik Harve和OriginalGriff提供的SQL语句非常有效，但是要抛出另一个变体，您还可以执行以下操作:

  SELECT  p.firstname，
       p.lastname，
       CAST(p.income/30001  AS   bit ) AS 富人
 FROM  tbl_person p 
 
 
 
Hallo,



I want to do a select statement which returns a boolean value



e.g.

select firstname, lastname, (income > 30000) as richperson from tbl_person




how can I syntactically do this with mssql? If i do it like shown above I get a syntax error
解决方案
you can do with case statement.



try this query..



select firstname, lastname, (case when income > 30000 then 'true' else 'false' end) as richperson from tbl_person




this will return true or false as varchar. if you want in boolean replace with 1 and 0 respectively.



select firstname, lastname, (case when income > 30000 then 1 else 0 end) as richperson from tbl_person
 

hope it helps..

Try: 
SELECT firstname, lastname, CASE WHEN income > 30000 THEN 1 ELSE 0 END AS richperson FROM tbl_person

First of all, SQL Server does not have a boolean data type. The closest equivalent is a bit. So this means that depending on your needs, you may have to ''translate'' the return value in your code before you use it.



The SQL statements provided by Karthik Harve and OriginalGriff are perfectly valid, but to throw another variant, you could also do something like:

SELECT p.firstname,
       p.lastname,
       CAST(p.income/30001 AS bit) AS richperson
FROM tbl_person p


                        
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