[英]Distinct LISTAGG that is inside a subquery in the SELECT list
這是我正在嘗試做的和我得到的最小的工作示例:
我有一個查詢如下:
/*
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的外鍵。
當前輸出:
ACCOUNT_ID TRANSACTION_ID TEAMS_REDIRECTED
---------- -------------- ----------------
1001 11 WWW, WWW, XXXXX
1001 12 UUU, UUU, VV
1002 13
預期產量:
我希望TEAMS_REDIRECTED
列中的重復項只能選擇一次,如下所示:
ACCOUNT_ID TRANSACTION_ID TEAMS_REDIRECTED
---------- -------------- ----------------
1001 11 WWW, XXXXX
1001 12 UUU, VV
1002 13
我嘗試了什么:
我tran_party
直接從tran_party
中選擇,而是編寫了一個內聯視圖,從tran_party中選擇不同的值,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;
雖然這確實給了我預期的輸出,但是當我在實際代碼中使用這個解決方案時,只需要13秒來檢索一行。 因此,我無法使用我已經嘗試過的東西。
任何幫助將不勝感激。
以下方法刪除了內聯視圖以獲取重復項,它使用LISTAGG
函數上的REGEXP_REPLACE
和RTRIM
來獲取aggregated list
的不同結果集。 因此,它不會進行多次掃描。
將此片段添加到您的代碼中
RTRIM(REGEXP_REPLACE(listagg (tm_redir.team_code, ',')
WITHIN GROUP (ORDER BY tm_redir.team_code),
'([^,]+)(,\1)+', '\1'),
',')
修改查詢 -
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>
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.