How I can eliminate commas in a concatenation when the records is not there

Question

I am getting these results
Holly Eliza Congdon, 2002, Son, John Harvey , 1981, other, , ,
Peter Allen, 1966, other, Duke Beardsley , 1992, other, , ,
Nellie Wood, 2011, Son, , , , , ,
Shawn Burns, 1986, other, , , , , ,
Jay Taylor, 1977, , , , , , ,
William Travis Stoll, 2013, Son, , , , , ,
Mary Beth Cockerham, 1982, , , , , , ,
Alice Tower Knapp, 1981, , Chris Tower Zafren , 1975, other, Dana Rose Tower, 2012, other
Jahd Khalil, 2011, Son, , , , , ,
Lauren Scott, 2009, other, , , , , ,
Danielle Restuccia, 2008, other, , , , , ,
I want to be able to NOT display the , , , , , (commas) if the record have only one relative
this records has 3
Alice Tower Knapp, 1981,Mother , Chris Tower Zafren , 1975, Other, Dana Rose Tower, 2012, Other
looks fine
but this one:
Jahd Khalil, 2011, Son, , , , , ,      LEG     09/20/2009 10:55:46
Only one, how I can eliminate the , , , , , ?
Here is the query:
SELECT spriden_pidm, 201090, '1', '1',
                   szcasup_relative1_name
                || ', '
                || szcasup_relative1_class
                || ', '
                || decode(szcasup_relative1_relation,'S','Siblings','O','Other','M','Mother','F','Father')
                || ', '
                || szcasup_relative2_name
                || ' , '
                || szcasup_relative2_class
                || ', '
                || decode(szcasup_relative2_relation,'S','Siblings','O','Other','M','Mother','F','Father')
                || ', '
                || szcasup_relative3_name
                || ', '
                || szcasup_relative3_class
                || ', '
                ||decode(szcasup_relative3_relation,'S','Siblings','O','Other','M','Mother','F','Father'),
                'LEG', SYSDATE
           FROM saturn_midd.szcasup, saturn.spriden
          WHERE spriden_ntyp_code = 'CAPP'
            AND szcasup_common_appl_id = spriden_id
            AND szcasup_relative1_name IS NOT NULLEdited by: peace4all on Sep 20, 2009 8:18 AM
Edited by: peace4all on Sep 20, 2009 8:18 AM

Answer 1

Maybe, but if there are trailing blanks
SELECT REGEXP_REPLACE('Jahd Khalil , 2011 , Son , , , , , , LEG 09/20/2009 10:55:46',' ,', '') FROM DUAL;
you need to take care of that first:
Jahd Khalil 2011 Son LEG 09/20/2009 10:55:46 <-- no commas at all!
1 row selected.
I guess there are many ways, and the old REPLACE is more than capable.
WITH dummydata AS (SELECT   'A' one,
                            'B' two,
                            NULL three,
                            'D' four
                     FROM   DUAL)
SELECT   one || ', ' || two || ', ' || three || ', ' || four record
  FROM   dummydata
UNION ALL
SELECT   REPLACE (record, ', ,', ',') record
  FROM   (SELECT   one || ', ' || two || ', ' || three || ', ' || four record
            FROM   dummydata)
UNION ALL
SELECT      one
         || CASE WHEN two IS NULL THEN '' ELSE ', ' END
         || two
         || CASE WHEN three IS NULL THEN '' ELSE ', ' END
         || three
         || CASE WHEN four IS NULL THEN '' ELSE ', ' END
         || four
            record
  FROM   dummydata