在 11g Listagg 中是最好的选择:
SQL> select tracking_num,
  2         listagg(title_of_doc_sec,',') within group (order by title_of_doc_sec) title_of_doc_sec
  3    from (select distinct tracking_num , title_of_doc_sec from some_table)
  4   group by tracking_num;
TRA TITLE_OF_DOC_SEC
--- ----------------------------------------------------------------------
007 Email Flow,Test Bug 53306,Title 1119,Title Test,test bug
009 1156
089 Title 21173
098 test Doc Section
10g 你可以使用wm_concat(但请注意这没有记录):
SQL> select tracking_num,
  2         wm_concat(title_of_doc_sec) title_of_doc_sec
  3    from (select distinct tracking_num , title_of_doc_sec from some_table)
  4   group by tracking_num;
TRA TITLE_OF_DOC_SEC
--- ----------------------------------------------------------------------
007 Title Test,test bug,Title 1119,Email Flow,Test Bug 53306
009 1156
089 Title 21173
098 test Doc Section
甚至是示范条款:
SQL> with data as (select distinct tracking_num , title_of_doc_sec from some_table)
  2  select tracking_num, title_of_doc_sec
  3    from (select *
  4            from data
  5          model
  6          partition by (tracking_num)
  7          dimension by (row_number() over (partition by tracking_num order by title_of_doc_sec) rn)
  8          measures (title_of_doc_sec t, cast(null as varchar2(4000)) title_of_doc_sec,
  9                    count(*) over (partition by tracking_num) cnt)
 10          rules(
 11            title_of_doc_sec[any] = case when t[cv() - 1 ] is null
 12                                        then t[cv()]
 13                                        else title_of_doc_sec[cv()-1]||', '|| t[cv()]
 14                                      end
 15          ))
 16   where cnt = rn;
TRA TITLE_OF_DOC_SEC
--- ----------------------------------------------------------------------
007 Email Flow, Test Bug 53306, Title 1119, Title Test, test bug
009 1156
089 Title 21173
098 test Doc Section