Question

我有这样的查询

有一个主要的CASE表达式，如果结果是1，那么我需要执行其他case语句，否则，下面的select语句。此查询无效。任何人都可以帮助我

DECLARE @sportCodeID INT;
SELECT @sportCodeID =   sport_code_id FROM jobs dlj where dlj.id = id;

(CASE WHEN (SELECT sport_code_id FROM jobs dlj WHERE dlj.id = id) = 1 THEN

CASE WHEN dl.action = 'C' THEN 'Cricker'

WHEN dl.action = 'F' THEN 'FOOTBALL'

)
(ELSE
(SELECT sport_codes from action_codes ac WHERE ac.id = @sportCodeID )

)END [Action]

Answer 1

以下是一些可能实现目标的代码

declare @jobs table(id int identity (1,1), sport_code_Id int)
insert @jobs (sport_code_Id) 
Select 1 UNION ALL 
Select 2 UNION ALL
Select 3 UNION ALL
Select 4

declare @action_codes table (id int identity(1,1), sport_codes char(1))
Insert @action_codes (sport_codes)
Select '1' UNION ALL 
Select 'F' UNION ALL
Select 'C' UNION ALL
Select '4'

Select * from @action_codes
Select * from @jobs

DECLARE @sportCodeID INT; 
SELECT @sportCodeID =   sport_code_id FROM @jobs dlj where dlj.id = 1; 
select @sportCodeID
SELECT 
    CASE sport_codes 
        WHEN 'F' THEN 'Football'
        WHEN 'C' THEN 'Criket'
        ELSE sport_codes
    END
FROM  @action_codes
WHERE id = @sportCodeID

如果您仍有疑问，请使用AdventureWorks数据库查看案例陈述中的示例。

USE AdventureWorks2008;
GO
SELECT   ProductNumber, Category =
      CASE ProductLine
         WHEN 'R' THEN 'Road'
         WHEN 'M' THEN 'Mountain'
         WHEN 'T' THEN 'Touring'
         WHEN 'S' THEN 'Other sale items'
         ELSE 'Not for sale'
      END,
   Name
FROM Production.Product
ORDER BY ProductNumber;
GO

SQL Server CASE表达式

1 个答案: