Please hep to generate same line number to print in file

Question

Hi
I am generating file by taking data from few tables. I need to generate file data from below structure data :
i.e In table A for order O having product p1,p2,p3,p4, lines will be wrriten to file in following manner
Line Number
O -p1 - 1
O -p2 - 2
O -p3 - 3
O -p4 - 4
Now another line is from table which will have only two product entries for the order O in below manner
i.e In table B for order O having product p2,p4. so for this lines should be match with above line number of order like this :
Line Number
O - p2 -2
O - p4 -4
First all data from table A will be writeen. Then only from TABLE B data should be wrriten to file.
Can anybody please help how to match line number for both the tables?
Thanks in advance

Answer 1

Perhaps a clearer output would be if we had different descriptions on each of the tables A an B to output with each of the rows..
SQL> ed
Wrote file afiedt.buf
  1  with A as (select 1 as order_id, 'p1' as product_id, 'A - order 1 product 1' as descr from dual union all
  2             select 1, 'p2', 'A - order 1 product 2' from dual union all
  3             select 1, 'p3', 'A - order 1 product 3' from dual union all
  4             select 1, 'p4', 'A - order 1 product 4' from dual union all
  5             select 2, 'p1', 'A - order 2 product 1' from dual union all
  6             select 2, 'p2', 'A - order 2 product 2' from dual union all
  7             select 2, 'p3', 'A - order 2 product 3' from dual)
  8      ,B as (select 1 as order_id, 'p2' as product_id, 'B - order 1 product 2' as descr from dual union all
  9             select 1, 'p4', 'B - order 1 product 4' from dual union all
10             select 2, 'p3', 'B - order 2 product 3' from dual)
11  -- end of test data
12  select order_id
13        ,product_id
14        ,row_number() over (partition by order_id order by product_id) as line_number
15        ,descr
16  from A
17  union all
18  select order_id, product_id, line_number, descr
19  from (
20    select b.order_id
21          ,b.product_id
22          ,row_number() over (partition by a.order_id order by a.product_id) as line_number
23          ,b.descr
24    from A left outer join B on (a.order_id = b.order_id and a.product_id = b.product_id)
25    )
26* where order_id is not null
SQL> /
  ORDER_ID PR LINE_NUMBER DESCR
         1 p1           1 A - order 1 product 1
         1 p2           2 A - order 1 product 2
         1 p3           3 A - order 1 product 3
         1 p4           4 A - order 1 product 4
         2 p1           1 A - order 2 product 1
         2 p2           2 A - order 2 product 2
         2 p3           3 A - order 2 product 3
         1 p2           2 B - order 1 product 2
         1 p4           4 B - order 1 product 4
         2 p3           3 B - order 2 product 3
10 rows selected.
SQL>