Ordering the records prior to select

Question

I have a table 'orderlines' with columns line_id, ship_flag, service_flag, bom_order.
I need to generate the order line number in the following way
select the orderlines order by bom_order
for the first line the line number is 1.0
for the next line if ship_flag is 'Y' then line_number is 1.1 else the line number is 2.0
for the next line if the previous line ship_flag was ' Y' and service_flag is 'Y' then line number is 1.1.1 else
if ship_flag is 'Y' then line number is 1.2, else 3.0
so we have a package UTIL and function get_number where there is a global variable to capture the previous numbers (line number, ship number and service number) and based on the flag increment appropriate number and generate the line number as varchar2.
I create a view
create or replace view order_with_lineno is
select line_id,
util.get_number(ship_flag, service_flag) as line_number,
from orderlines order by bom_order;
This view doesnot give me the correct line_number, becaue the sorting happen after the line_number generation is done.
can someone give me a solution for this?

Answer 1

This is making some assumptions about how your flags are set, but if the data looks like the following, you can use a query for this:
create table orderlines
bom_order number,
line_id number,
ship_flag varchar2(1),
service_flag varchar2(1)
delete from orderlines;
insert into orderlines values (1000,10,'N','N');
insert into orderlines values (1000,20,'Y','N');
insert into orderlines values (1000,30,'N','Y');
insert into orderlines values (1000,40,'N','Y');
insert into orderlines values (1000,50,'Y','N');
insert into orderlines values (1000,60,'N','Y');
insert into orderlines values (1000,70,'N','Y');
insert into orderlines values (1000,80,'N','Y');
insert into orderlines values (2000,10,'N','N');
insert into orderlines values (2000,20,'Y','N');
commit;
SELECT bom_order,
       line_id,
       l1||'.'||l2||decode(l3,0,'','.'||l3) new_line_id
FROM   (
        SELECT bom_order,
               line_id,
               l1,
               l2,
               sum(decode(service_flag,'Y',1,0)) OVER (PARTITION BY bom_order,l2 ORDER BY line_id  ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) l3
        FROM
                SELECT bom_order,
                       line_id,
                       service_flag,
                       dense_rank() OVER (ORDER BY bom_order) l1,
                       sum(decode(ship_flag,'Y',1,0)) OVER (PARTITION BY bom_order ORDER BY line_id  ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) l2
                FROM   orderlines
BOM_ORDER    LINE_ID NEW_LINE_ID
      1000         10 1.0
      1000         20 1.1
      1000         30 1.1.1
      1000         40 1.1.2
      1000         50 1.2
      1000         60 1.2.1
      1000         70 1.2.2
      1000         80 1.2.3
      2000         10 2.0
      2000         20 2.1Greg Pike
http://www.singlequery.com
Message was edited by:
gfpike
Had a raw data error.