SQL服务器触发器自定义PK

Question

我想通过触发器生成PK，因为它是自定义PK。

这就像取决于成员类型字段一样，我想生成PK成员id。

例如如果新记录的成员类型为DGIA，则成员标识为DGIA1，DGIA2，DGIA3 ...等等...如果成员类型为DGIL，则成员标识为DGIL1，DGIL2，DGIL3 ...等等。 ..

所以，如何写触发器相同...我已经尝试了以下，但它只为第一条记录工作。

ALTER TRIGGER [dbo].[next_member_id] ON [dbo].[DAD_MEMBERSHIP] AFTER INSERT 
AS 
BEGIN 

DECLARE @COUNT INT 
SET @COUNT=0; 

SELECT @COUNT=ISNULL(MAX(CAST(SUBSTRING(DAD_MEMBERSHIP.MEMBER_ID,5,15) AS INT)),0)+1 FROM DAD_MEMBERSHIP where DAD_MEMBERSHIP.MEMBER_TYPE = DAD_MEMBERSHIP.MEMBER_TYPE 

update DAD_MEMBERSHIP set DAD_MEMBERSHIP.MEMBER_ID = DAD_MEMBERSHIP.MEMBER_TYPE + CONVERT(varchar,@COUNT) 
from DAD_MEMBERSHIP inner join inserted on DAD_MEMBERSHIP.MEMBER_TYPE = inserted.MEMBER_TYPE 

END 

Answer 1

我解决了使用以下触发

ALTER TRIGGER [dbo].[next_member_id] 
    ON [dbo].[DAD_MEMBERSHIP] 
    AFTER INSERT 
AS 
BEGIN 

DECLARE @COUNT INT 
SET @COUNT=0; 

DECLARE @STR VARCHAR(5) 
SET @STR='' 

select @STR=i.MEMBER_TYPE from inserted i; 

SELECT @COUNT=ISNULL(MAX(CAST(SUBSTRING(DAD_MEMBERSHIP.MEMBER_ID,5,15) AS INT)),0)+1 
from DAD_MEMBERSHIP where MEMBER_TYPE=@STR 

update DAD_MEMBERSHIP set DAD_MEMBERSHIP.MEMBER_ID = @STR + CONVERT(varchar,@COUNT) 
from DAD_MEMBERSHIP inner join inserted i on i.MEMBER_TYPE=DAD_MEMBERSHIP.MEMBER_TYPE where DAD_MEMBERSHIP.MEMBER_ID is null 



END 

Answer 2

触发器通过批处理记录进行操作，您不能分配给标量变量，并期望它可以处理多个记录。你需要重新考虑你的整个过程到一个基于集合的过程。