How to achive this using analytical function-- please help

Question

version 10g.
this code works just fine with my requirement. i am tyring to learn analytical functions and implement that in the below query. i tried using row_number ,
but i could nt achive the desired results. please give me some ideas.
SELECT c.tax_idntfctn_nmbr irs_number, c.legal_name irs_name,
       f.prvdr_lctn_iid
  FROM tax_entity_detail c,
       provider_detail e,
       provider_location f,
       provider_location_detail pld
WHERE c.tax_entity_sid = e.tax_entity_sid
   AND e.prvdr_sid = f.prvdr_sid
   AND pld.prvdr_lctn_iid = f.prvdr_lctn_iid
   AND c.oprtnl_flag = 'A'
   AND c.status_cid = 2
   AND e.oprtnl_flag = 'A'
   AND e.status_cid = 2
   AND (c.from_date) =
          (SELECT MAX (c1.from_date)
             FROM tax_entity_detail c1
            WHERE c1.tax_entity_sid = c.tax_entity_sid
              AND c1.oprtnl_flag = 'A'
              AND c1.status_cid = 2)
   AND (e.from_date) =
          (SELECT MAX (c1.from_date)
             FROM provider_detail c1
            WHERE c1.prvdr_sid = e.prvdr_sid
              AND c1.oprtnl_flag = 'A'
              AND c1.status_cid = 2)
   AND pld.oprtnl_flag = 'A'
   AND pld.status_cid = 2
   AND (pld.from_date) =
          (SELECT MAX (a1.from_date)
             FROM provider_location_detail a1
            WHERE a1.prvdr_lctn_iid = pld.prvdr_lctn_iid
              AND a1.oprtnl_flag = 'A'
              AND a1.status_cid = 2)thanks
Edited by: new learner on May 24, 2010 7:53 AM
Edited by: new learner on May 24, 2010 10:50 AM

Answer 1

May be like this not tested...
select *
from
SELECT c.tax_idntfctn_nmbr irs_number, c.legal_name irs_name,
f.prvdr_lctn_iid, c.from_date as c_from_date, max(c.from_date) over(partition by c.tax_entity_sid) as max_c_from_date,
e.from_date as e_from_date, max(e.from_date) over(partition by e.prvdr_sid) as max_e_from_date,
pld.from_date as pld_from_date, max(pld.from_date) over(partition by pld.prvdr_lctn_iid) as max_pld_from_date
FROM tax_entity_detail c,
provider_detail e,
provider_location f,
provider_location_detail pld
WHERE c.tax_entity_sid = e.tax_entity_sid
AND e.prvdr_sid = f.prvdr_sid
AND pld.prvdr_lctn_iid = f.prvdr_lctn_iid
AND c.oprtnl_flag = 'A'
AND c.status_cid = 2
AND e.oprtnl_flag = 'A'
AND e.status_cid = 2
AND pld.oprtnl_flag = 'A'
AND pld.status_cid = 2
)X
where c_from_date=max_c_from_date AND e_from_date =max_e_from_date AND
pld_from_date=max_pld_from_date