create or replace trigger trigger_on_id before insert on Attach
for each row
begin
select seq_attach_id.nextval into :new.id from dual;
end;
for each row
begin
select seq_attach_id.nextval into :new.id from dual;
end;
INSERT INTO Attach
SELECT seq_attach_id.nextval,COL2_OFBIZ,COL2_OFBIZ,...