Question

I have tried it but not successful so far. Since my knowledge in query is limited, I thought I will better post it here.

I have students table with the following structure

create table students(
id int not null primary key identity,
sname varchar(25),
status varchar(25),
renew varchar(15),
enrollment datetime,
)

I have a number of students who has an ID, studentName(sname),status(‘active’ or ‘not-active’), renew(‘no’ for new student, yes’ for renewed student) and enrollment date.

insert into students values('jay','active','no','2010-01-01')
insert into students values('Phil','active','no','2010-01-01')
insert into students values('Cru','active','no','2010-01-01')
insert into students values('slow','active','no','2010-01-01')
insert into students values('true','active','no','2010-01-01')
insert into students values('false','active','no','2010-01-01')

Now I have an INSERT Trigger which is suppose to deactive an old student when a student is renewed. So if I insert the following which has renewal set to ‘yes’, it should make the already existing record ‘inactive’.

insert into students values('false','active','yes','2011-01-01')

I wrote this INSERT Trigger and it works but it in-actives the old and the new inserted record both. I want only the original record to be inactivated. Also not that only enrollment date and nenew fields are different, the rest are the same between original and insert records. How to fix this? Here is my trigger

set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
GO
CREATE TRIGGER [dbo].[tr_renew_student]
ON [dbo].students
-- WITH ENCRYPTION
FOR INSERT
-- WITH APPEND
-- NOT FOR REPLICATION
AS
-- insert sql here
if exists(select * from inserted where Renew = 'yes')
BEGIN

UPDATE students 
    SET status = 'Inactive'

    FROM Inserted i
        INNER JOIN students T2
            ON i.sname = T2.sname

END

Note that this is close approximation to my problem. Thank you

Answer 1

Have you looked at @@identity? Years back I dealt with something similar and used @@identity to get the last created identity value; basically getting the latest identity value then setting all the records matching the criteria except the one with the ID returned via @@identity.

Read about the identity value getters here:
http://blog.sqlauthority.com/2007/03/25/sql-server-identity-vs-scope_identity-vs-ident_current-retrieve-last-inserted-identity-of-record/

Added: You’re right about the inserted table. If you didn’t want to / can’t use the inserted table, your trigger could look something like this.

SELECT @@identity //  <- this gets the last identity value inserted.

UPDATE students
SET status = 'Inactive'
WHERE students.name = (SELECT name FROM students WHERE id = @@identity)
  AND id <> @@identity

Note: written from memory and not tested.