Sql 当条件基于当前行值时

在我的

SELECT

query中，我想在我的

CASE

中为名为IsActive的值设置一个条件，以便如果当前行的列类型为“adhoc”，则将IsActive的值设置为“n/a”

但是当（Type）=“adhoc”然后是“n/a”时，我在

行中得到了这个错误：

“=”附近的语法不正确

如何根据当前行的条件做出决定？
试试以下方法：

SELECT (CASE Type
            WHEN 'scheduled' THEN 'Scheduled'
            WHEN 'adhoc' THEN 'AdHoc'
            ELSE 'Unknown'
        END) AS 'Type',
       (CASE 
            WHEN Type = 'adhoc' THEN 'n/a'
            WHEN IsActive = 0 THEN 'Stopped'
            WHEN IsActive = 1 THEN 'Active'
        END) AS 'Status'
FROM MyTable;

您的第二个
案例
基于一个列，然后您试图在
中添加一个条件，当
时，这是不允许的：

CASE IsActive 
            WHEN (Type) = 'adhoc' THEN 'n/a'
            WHEN 0 THEN 'Stopped'
            WHEN 1 THEN 'Active'
       END AS 'Status'

我想您是有意这样做的（使用一个不带列的
案例
，并在
时将条件放入
）：

MS Sql Server不支持当前的计算行操作。
为了实现这一目标，您必须提到Cte

with cteType as (
SELECT CASE Type
            WHEN 'scheduled' THEN 'Scheduled'
            WHEN 'adhoc' THEN 'AdHoc'
            ELSE 'Unknown'
       END AS 'Type'
FROM MyTable)

select Type
,
       CASE IsActive 
            WHEN (Type) = 'adhoc' THEN 'n/a'
            WHEN 0 THEN 'Stopped'
            WHEN 1 THEN 'Active'
       END AS 'Status'
FROM cteType 

这将起作用
Pedram jaan您的查询如下：

SELECT CASE [Type]
            WHEN 'scheduled' THEN 'Scheduled'
            WHEN 'adhoc' THEN 'AdHoc'
            ELSE 'Unknown'
       END AS 'Type',
       CASE  
            WHEN [Type] = 'adhoc' THEN 'n/a'
            WHEN IsActive = 0 THEN 'Stopped'
            WHEN IsActive = 1 THEN 'Active'
       END AS 'Status'
FROM dbo.MyTable

使用括号中的类型，如[Type]。这是一个关键词。
Pedram jaan？哈哈，妈妈！你的回答是正确的。但恐怕我得选一个早些时候发布的。
SELECT CASE Type
        WHEN 'scheduled' THEN 'Scheduled'
        WHEN 'adhoc' THEN 'AdHoc'
        ELSE 'Unknown'
   END AS 'Type',
   CASE WHEN [Type] = 'adhoc' THEN 'n/a'                        
        WHEN IsActive = 0 THEN 'Stopped'
        WHEN IsActive = 1 THEN 'Active'
   END AS 'Status'
FROM MyTable

with cteType as (
SELECT CASE Type
            WHEN 'scheduled' THEN 'Scheduled'
            WHEN 'adhoc' THEN 'AdHoc'
            ELSE 'Unknown'
       END AS 'Type'
FROM MyTable)

select Type
,
       CASE IsActive 
            WHEN (Type) = 'adhoc' THEN 'n/a'
            WHEN 0 THEN 'Stopped'
            WHEN 1 THEN 'Active'
       END AS 'Status'
FROM cteType 

SELECT CASE [Type]
            WHEN 'scheduled' THEN 'Scheduled'
            WHEN 'adhoc' THEN 'AdHoc'
            ELSE 'Unknown'
       END AS 'Type',
       CASE  
            WHEN [Type] = 'adhoc' THEN 'n/a'
            WHEN IsActive = 0 THEN 'Stopped'
            WHEN IsActive = 1 THEN 'Active'
       END AS 'Status'
FROM dbo.MyTable