Need Sequence for this logic

Question

Hi,
I need sequence for autogenerate of code
Table 1
id     code
We need to autogenerate code for every new entity of id 
ex:
id          code
sbi        sbi001
hsb        hsb002 
xyz        xyz003
And
ex:
id          code
sbi      s001
hsb     h002
xyz    x003

Answer 1

You can use a Sequence and Trigger in combination like this
create table t
  id   varchar2(10)
, code varchar2(25)
create sequence t_seq;
create or replace trigger t_trig before insert on t for each row
declare
  l_seq integer;
begin
  select t_seq.nextval into l_seq from dual;
  :new.code := :new.id || to_char(l_seq, 'fm099');
end;
insert into t (id) values ('sbi');
insert into t (id) values ('hsb');
insert into t (id) values ('xyz');
select * from t;