after trigger update statement take long time - sql

Question

I created a trigger as below
alter trigger sale_Trigger_Update on sale
after update
as
begin
Declare #old_value varchar(50)
Declare #new_value varchar(50)
Declare #sale_id UNIQUEIDENTIFIER
DECLARE new_cur CURSOR FORWARD_ONLY READ_ONLY LOCAL FOR
SELECT saleid
FROM INSERTED
open new_cur
Fetch Next from new_cur into #sale_id
while ##FETCH_STATUS = 0
Begin
set #old_value = (select enddate from deleted where SaleID = #sale_id)
set #new_value = (select enddate from inserted where SaleID = #sale_id)
insert into zzz (old_value,new_value) values(#old_value,#new_value)
end
CLOSE new_cur
DEALLOCATE new_cur
end
Then I do an update statement as below
update sale
set enddate = null
Sale table contain only 2 rows
and the execution is continuing unlimited.
I tried
update sale
set enddate = null
where saleid = 10
same problem.
Then I forcefully stopped the execution. Then checked the sale table and zzz table. No changes happened.
I am sure there is some issue in cursor. Can somebody show some light on it.
****Edited****
Actually I need to check enddate in deleted is null and enddate in inserted is not null
open new_cur
Fetch Next from new_cur into #sale_id
while ##FETCH_STATUS = 0
Begin
set #old_value = (select enddate from deleted where SaleID = #sale_id)
set #new_value = (select enddate from inserted where SaleID = #sale_id)
if #old_value = null and #new_value != null
begin
SELECT approval.*,
(select diag.*
from diag diag
where approval.id =diag.id
FOR XML PATH('diag'), TYPE
),
(select ser.*
from ser ser
where approval.id =ser.id
FOR XML PATH('ser'), TYPE
)
FROM approval approval,
where approval.id = 1
and approval.saleid =#saleid
FOR XML PATH, ELEMENTS,
root('Head')
end if
end
CLOSE new_cur
DEALLOCATE new_cur

Answer 1

Regarding the cursor.
Could you replace your trigger with?
alter trigger sale_Trigger_Update on sale
after update
as
begin
insert into zzz (old_value,new_value)
select
--i.SalesID,
d.enddate,
i.enddate
from inserted i
inner join deleted d on
i.SaleID = d.SaleID
where
d.enddate is null and
i.enddate is not null
end