select item_id from table A where stu_id="12345', and item_id is a integer,
I want to do item_id=item_id +1 on my next insert
the following code in my trigger is not working
DECLARE
app_item_no integer := 0;
BEGIN
select TO_NUMBER(item_id)
into app_item_no
from A where stu_id=:Old.stu_id;
TO_NUMBER(app_item_no)=TO_NUMBER(app_item_no)+1;