Question

I want to generate PK through trigger as it is custom PK.

It is like depending on the member type field, I want to generate member id which is PK.

e.g. if new record’s member type is DGIA, then member id will be DGIA1, DGIA2, DGIA3 …and so on… if member type is DGIL, then member id will be DGIL1, DGIL2, DGIL3 …and so on…

So, how to write trigger for the same… I have tried as following but it is working for 1st record only.

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

I solved the problem using following trigger

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