Need tuning in sql

Question

I have three tables - fund_family a, fund b, fund_registration c. currently the below query is being used to display two columns
fund_family_id and fund_family_nm with fund_family_nm as order by.
select distinct
a.fund_family_id,
a.fund_family_nm,
from
fund_family a, fund b, fund_registration c
where
a.fund_family_id = b.fund_family_id
and b.fund_id = c.fund_id
and c.mail_delivery='Y'
and c.registered_in = 'Y'
and EXISTS (
select 'x' from country_table_id
where b.tr_cd in ('TR05,'TR18')
and d.country_id = c.country_id
and d.web_site_id = '4')
order by a.fund_family_nm
now we need to change the current sorting order of fund_family_nm based on one column in fund table. Now the scenario is -- in fund table, there are
list of fund_id which belongs to some fund_family_id (i.e. suppose one fund_family_id is 1500 and in this fund_family_id there can be n number of fund_id in fund table. now in fund table there is one column called tr_code which is having either one value TR05 or TR18. now we have to sort the fund_family_nm in such a way that first it should display all the fund_family_nm whose fund_id are having tr_code value as TR05 first and then display TR18.
I just tried the below query but I am getting duplicate row for fund_family_nm whose value falls under TR05 and TR18. so can you please help me to tune this sql so that i should not get duplicate rows.
select distinct
a.fund_family_id,
a.fund_family_nm,
b.tr_code
from
fund_family a, fund b, fund_registration c
where
a.fund_family_id = b.fund_family_id
and b.fund_id = c.fund_id
and c.mail_delivery='Y'
and c.registered_in = 'Y'
and EXISTS (
select 'x' from country_table_id
where b.tr_cd in ('TR05,'TR18')
and d.country_id = c.country_id
and d.web_site_id = '4')
order by tr_cd --a.fund_family_nm
Edited by: user11439255 on Jan 9, 2011 2:47 AM

Answer 1

in such a way that first it should display all the fund_family_nm whose fund_id are having tr_code value as TR05 first and then display TR18.?? You want just one row right or two rows? If it has the values TR05 AND TR18 you want to see just TR18, right?
(You use tr_cd and tr_code but I assume that's the same field)
The solution of Etbin would work, but additionally, if the question is about tuning, I'd recommend the usage of JOIN over EXISTS.
SELECT fund_family_id, fund_family_nm, tr_code FROM (
          SELECT a.fund_family_id,a.fund_family_nm,b.tr_cd,
                  ROW_NUMBER() OVER (PARITITION BY a.fund_family_id,a.fund_family_nm ORDER BY b.tr_cd desc) RN
          from fund_family a
          INNER JOIN fund b
           ON a.fund_family_id = b.fund_family_id
          INNER JOIN fund_registration c
           ON b.fund_id = c.fund_id
          INNER JOIN (SELECT DISTINCT country_id FROM country_table_id WHERE d.web_site_id = '4') d
           ON (d.country_id = c.country_id)
          WHERE
               c.mail_delivery='Y'
          and c.registered_in = 'Y'
          and b.tr_cd in ('TR05,'TR18'))
WHERE rn =1          
order by tr_code;