Query to Generate XML Data Node

select lpad(' ',13*1,' ') || a from (
select * from (
SELECT ', ( SELECT XMLElement'                       a   , 'A01' from dual union
SELECT '           ( "-List"'               , 'A02' from dual union
SELECT '           , XMLAgg'                          , 'A03' from dual union
SELECT '             ( XMLElement'                   , 'A04' from dual union
SELECT '               ( "-"'             , 'A05' from dual union
SELECT '               , XMLAttributes'               , 'A06' from dual union
SELECT '                 ( class_code as "-ID"' , 'A07' from dual union
SELECT '                 ) '                          , 'A08' from dual union
SELECT '                 , XMLElement'                , 'A09' from dual union
SELECT '                   ( "-Details"'        , 'A10' from dual union
SELECT '                   , XMLforest'               , 'A11' from dual union
SELECT '                     (' a                     , 'A12' from dual union
select * from ( select lpad(', ', 24, ' ') ||
                       rpad(column_name,30,' ') ||
                       ' as "' ||
                       replace(initcap(replace(column_name, '_', ' ')),' ') ||
                       '"' b, 'B' || column_name
                  from dba_tab_columns
                 where table_name = upper('ap_pay_group')
              )                       
union                              
select '                     )'                    , 'C01' from dual UNION
select '                   )'                      , 'C02' from dual UNION
select '               )'                        , 'C03' from dual UNION
select '             )'                          , 'C04' from dual UNION
select '           )'                            , 'C05' from dual UNION
select '      from ap_pay_group apg '                , 'C06' from dual UNION
select '     where apg.checkrun_id = isc.checkrun_id '                           , 'C07' from dual UNION
select '  )'                                        , 'C08' from dual
)
order by 2)