SELECT列表中子查询内的不同LISTAGG

Question

这是我正在尝试做的事情和获得的最简单的工作示例：

我有一个查询，如下所示：

/*
with tran_party as -- ALL DUMMY DATA ARE IN THESE CTE FOR YOUR REFERENCE
         (select 1 tran_party_id, 11 transaction_id, 101 team_id_redirect
            from dual
          union all
          select 2, 11, 101 from dual
          union all
          select 3, 11, 102 from dual
          union all
          select 4, 12, 103 from dual
          union all
          select 5, 12, 103 from dual
          union all
          select 6, 12, 104 from dual
          union all
          select 7, 13, 104 from dual
          union all
          select 8, 13, 105 from dual),
     tran as
         (select 11 transaction_id, 1001 account_id, 1034.93 amount from dual
          union all
          select 12, 1001, 2321.89 from dual
          union all
          select 13, 1002, 3201.47 from dual),
     account as
         (select 1001 account_id, 111 team_id from dual
          union all
          select 1002, 112 from dual),
     team as
         (select 101 team_id, 'UUU' as team_code from dual
          union all
          select 102, 'VV' from dual
          union all
          select 103, 'WWW' from dual
          union all
          select 104, 'XXXXX' from dual
          union all
          select 105, 'Z' from dual)
-- */
-- The Actual Query
select a.account_id,
       t.transaction_id,
       (select listagg (tm_redir.team_code, ', ')
                   within group (order by tm_redir.team_code)
          from tran_party tp_redir
               inner join team tm_redir
                   on tp_redir.team_id_redirect = tm_redir.team_id
               inner join tran t_redir
                   on tp_redir.transaction_id = t_redir.transaction_id
         where     t_redir.account_id = a.account_id
               and t_redir.transaction_id != t.transaction_id)
           as teams_redirected
  from tran t inner join account a on t.account_id = a.account_id;

注意： tran_party.team_id_redirect 是引用 team.team_id 的外键。

电流输出：

ACCOUNT_ID TRANSACTION_ID TEAMS_REDIRECTED
---------- -------------- ----------------
1001       11             WWW, WWW, XXXXX
1001       12             UUU, UUU, VV
1002       13

预期产量：

我希望TEAMS_REDIRECTED列中的重复项仅被选择一次，如下所示：

ACCOUNT_ID TRANSACTION_ID TEAMS_REDIRECTED
---------- -------------- ----------------
1001       11             WWW, XXXXX
1001       12             UUU, VV
1002       13

我试过的

tran_party我写了一个内联视图，而不是直接从中选择，而是从tran_party中选择不同的值，如下所示：

select a.account_id,
       t.transaction_id,
       (select listagg (tm_redir.team_code, ', ')
                   within group (order by tm_redir.team_code)
          from (select distinct transaction_id, team_id_redirect -- Note this inline view
                  from tran_party) tp_redir
               inner join team tm_redir
                   on tp_redir.team_id_redirect = tm_redir.team_id
               inner join tran t_redir
                   on tp_redir.transaction_id = t_redir.transaction_id
         where     t_redir.account_id = a.account_id
               and t_redir.transaction_id != t.transaction_id)
           as teams_redirected
  from tran t inner join account a on t.account_id = a.account_id;

尽管这确实给了我预期的输出，但是当我在实际代码中使用此解决方案时，只需要一行大约13秒钟即可检索到一行。因此，我无法使用已经尝试过的东西。

任何帮助将不胜感激。

Answer 1

以下方法摆脱了嵌入式视图以获取重复项，它使用REGEXP_REPLACE和RTRIM在LISTAGG函数上获取中的不同结果集aggregated list。因此，它不会进行多次扫描。

将此片段添加到您的代码中，

RTRIM(REGEXP_REPLACE(listagg (tm_redir.team_code, ',') 
                     WITHIN GROUP (ORDER BY tm_redir.team_code),
                     '([^,]+)(,\1)+', '\1'),
                     ',')

修改后的查询-

SQL> with tran_party as -- ALL DUMMY DATA ARE IN THESE CTE FOR YOUR REFERENCE
  2           (select 1 tran_party_id, 11 transaction_id, 101 team_id_redirect
  3              from dual
  4            union all
  5            select 2, 11, 101 from dual
  6            union all
  7            select 3, 11, 102 from dual
  8            union all
  9            select 4, 12, 103 from dual
 10            union all
 11            select 5, 12, 103 from dual
 12            union all
 13            select 6, 12, 104 from dual
 14            union all
 15            select 7, 13, 104 from dual
 16            union all
 17            select 8, 13, 105 from dual),
 18       tran as
 19           (select 11 transaction_id, 1001 account_id, 1034.93 amount from dual
 20            union all
 21            select 12, 1001, 2321.89 from dual
 22            union all
 23            select 13, 1002, 3201.47 from dual),
 24       account as
 25           (select 1001 account_id, 111 team_id from dual
 26            union all
 27            select 1002, 112 from dual),
 28       team as
 29           (select 101 team_id, 'UUU' as team_code from dual
 30            union all
 31            select 102, 'VV' from dual
 32            union all
 33            select 103, 'WWW' from dual
 34            union all
 35            select 104, 'XXXXX' from dual
 36            union all
 37            select 105, 'Z' from dual)
 38  -- The Actual Query
 39  select a.account_id,
 40         t.transaction_id,
 41         (SELECT  RTRIM(
 42           REGEXP_REPLACE(listagg (tm_redir.team_code, ',')
 43                     WITHIN GROUP (ORDER BY tm_redir.team_code),
 44             '([^,]+)(,\1)+', '\1'),
 45           ',')
 46            from tran_party tp_redir
 47                 inner join team tm_redir
 48                     on tp_redir.team_id_redirect = tm_redir.team_id
 49                 inner join tran t_redir
 50                     on tp_redir.transaction_id = t_redir.transaction_id
 51           where     t_redir.account_id = a.account_id
 52                 and t_redir.transaction_id != t.transaction_id)
 53             AS teams_redirected
 54    from tran t inner join account a on t.account_id = a.account_id
 55  /

ACCOUNT_ID TRANSACTION_ID TEAMS_REDIRECTED
---------- -------------- --------------------
      1001             11 WWW,XXXXX
      1001             12 UUU,VV
      1002             13

SQL>