Hi all i am trying to use a Connect by prior clause

Question

Hi all,
In my connect by prior clause i have a query. I want to pass the values to the query from my outer query. Can this be done in Oracle.Can any help me in this.Also Pasting my query for your reference
SELECT rct2.trx_number
     , rctl2.customer_trx_line_id
     , fifs.flex_value_set_id
     , gcc.code_combination_id
     , ffvc.child_flex_value
     , ffvc.parent_flex_value
     , gcc.segment4
     , ffvc.description
     , ffvc.lvl
FROM   ra_customer_trx_all rct2
      ,ra_customer_trx_lines_all rctl2
      ,ra_cust_trx_line_gl_dist_all rctlgd
      ,gl_code_combinations gcc
      , (SELECT     ffvv.flex_value_set_id
                  , ffvv.flex_value child_flex_value
                  , LEVEL lvl, ffvv.parent_flex_value
                  , ffvv.description
               FROM fnd_flex_value_children_v ffvv
              WHERE 1 = 1
              START WITH  ffvv.flex_value = (SELECT 
      gcc.segment4
  FROM ra_customer_trx_all rct1,
       ra_customer_trx_lines_all rctl1,
       ra_cust_trx_line_gl_dist_all rctlgd,
       gl_code_combinations gcc
WHERE rct1.customer_trx_id=rctl1.customer_trx_id
AND rctl1.customer_trx_line_id=rctlgd.customer_trx_line_id
AND  rct1.customer_trx_id=rctlgd.customer_trx_id
AND rctlgd.account_class = 'REV'
AND rctlgd.code_combination_id=gcc.code_combination_id
AND rct1.trx_number            = :trx_number--Want to pass  rct2.trx_number here which is coming from outer query
AND rctla.customer_trx_line_id = :trx_line_id)--Want to pass rctl2.customer_trx_line_id here which is coming from outer query
         CONNECT BY PRIOR ffvv.parent_flex_value = ffvv.flex_value  ) ffvc
      ,fnd_flex_value_sets s
      ,fnd_id_flex_segments fifs
      ,gl_ledgers l
WHERE rct2.customer_trx_id           = rctl2.customer_trx_id
   AND rctl2.customer_trx_line_id   = rctlgd.customer_trx_line_id
   AND rct2.customer_trx_id          = rctlgd.customer_trx_id
   AND rctlgd.code_combination_id   = gcc.code_combination_id
   AND fifs.flex_value_set_id       = ffvc.flex_value_set_id
   AND fifs.application_id          = 101
   AND fifs.flex_value_set_id       = s.flex_value_set_id
   AND fifs.application_column_name = 'SEGMENT4'
   AND fifs.id_flex_code            = 'GL#'
   AND l.chart_of_accounts_id       = fifs.id_flex_num
   AND l.ledger_id                  = rct2.set_of_books_id
   AND rctlgd.account_class         = 'REV'
   AND rctl2.customer_trx_line_id   = :trx_line_id --Pass Trx id
   AND rct2.trx_number              = :trx_number  --Pass trx number

Answer 1

Hello.
"I created a function and added the above query to the function and passed the values  as parameters at both places"
Well, this is not the best idea, because adding a function to your SQL will add many context switches (depending on the volume of your data) and may badly affect the CBO to choose not optimal execution plan. That's why it is better to avoid it if possible. Actually, I found no problem in using correlated subquery in the start with clause:
with
    t1 as (
        select 1 as id, null as pid from dual
        union all
        select 2, 1 from dual
        union all
        select 3, 1 from dual
        union all
        select 5, 2 from dual
    t2 as (
        select 1 as t2id from dual
        union all
        select 2 as t2id from dual
select lpad(' ', 2 * (level-1)) || t1.id as id
    , level
    , case when t1.id = connect_by_root t1.id then 'ROOT' else null end as ROOT
from t1
start with t1.id = (select t2.t2id from t2 where t2.t2id = t1.id)
connect by prior t1.id = t1.pid
order siblings by t1.id;
ID
LEVEL
ROOT
1
1
ROOT
  2
2
    5
3
  3
2
2
1
ROOT
  5
2
But, as Frank Kulash reasonably said, depending on the volume that you work with, it may probably be better to do the join before the connect by like this for example:
with
    t1 as (
        select 1 as id, null as pid from dual
        union all
        select 2, 1 from dual
        union all
        select 3, 1 from dual
        union all
        select 5, 2 from dual
    t2 as (
        select 1 as t2id from dual
        union all
        select 2 as t2id from dual
select lpad(' ', 2 * (level-1)) || t1.id as id
    , level
    , case when t1.id = connect_by_root t1.id then 'ROOT' else null end as ROOT
from t1 left join t2 on t1.id = t2.t2id
start with t2.t2id is not null
connect by prior t1.id = t1.pid
order siblings by t1.id
ID
LEVEL
ROOT
1
1
ROOT
  2
2
    5
3
  3
2
2
1
ROOT
  5
2