Listagg 不同值

Question

你好，我需要 select 一个只包含不同值的 listagg 列。不幸的是，我使用的是 oracle 18.c，它不支持直接不同的选项，所以我可能必须使用嵌套的 select（不确定？）我有以下 SQL 查询，我需要列出具有不同值的 "adrml.email" 列。

select distinct
c.trader_transact
, t.trader_descr
, d.third
, d.f_name
, d.def_phone
, d.def_mail
, d.f_city
, d.country_descr
, d.f_street
, con.first_name
, con.last_name
, adrph.formated_phone_nr
, link.adr
, link.contact
,adrdet.dt
,adrdet.street Contact_Street
,adrdet.post_code
,adrdet.city
,adrdet.country
,adrml.email
 ,LISTAGG(
        adrml.email,
        ' / '
    ) WITHIN GROUP(

    ORDER BY
        d.third
    )

from thr_v_third d
join tra_contract c on d.third = c.customer or d.third = c.supplier
join tra_trader t on t.trader = c.trader_transact
join thr_v_adr_lnk_contact link on link.third = d.third --and link.type = 1 and link.default_contact = 1
join adr_contact con on con.adr = link.adr and con.contact = link.contact
join adr_address_det adrdet on adrdet.adr = link.adr and adrdet.last = 1
left join adr_mail adrml on link.adr = adrml.adr and con.contact = adrml.contact and adrml.deflt = 1
left join adr_v_phones adrph on adrph.adr = link.adr and adrph.contact = link.contact and adrph.deflt = 1 and adrph.type = 1
where t.trader = 32
group by
c.trader_transact
, t.trader_descr 
 ,d.third
, d.f_name
, d.def_phone
, d.def_mail
, d.f_city
, d.country_descr
, d.f_street
, link.adr
, link.contact
, con.first_name
, con.last_name
,adrdet.dt
,adrdet.street
,adrdet.post_code
,adrdet.city
,adrdet.country
,adrml.email
, adrph.formated_phone_nr 
order by d.third

到目前为止，我在 listagg 列中收到了重复的电子邮件。我该如何清除它？

Answer 1

这是你拥有的：

SQL> select d.dname,
  2         listagg(e.job, ', ') within group (order by e.job) jobs
  3  from dept d join emp e on e.deptno = d.deptno
  4  group by d.dname;

DNAME          JOBS
-------------- ------------------------------------------------------------
ACCOUNTING     CLERK, MANAGER, PRESIDENT
RESEARCH       ANALYST, ANALYST, CLERK, CLERK, MANAGER
SALES          CLERK, MANAGER, SALESMAN, SALESMAN, SALESMAN, SALESMAN

这就是你想要的：

SQL> select x.dname,
  2         listagg(x.job, ', ') within group (order by x.job) jobs
  3  from (select distinct d.dname,
  4                        e.job
  5        from dept d join emp e on e.deptno = d.deptno
  6       ) x
  7  group by x.dname;

DNAME          JOBS
-------------- ------------------------------------------------------------
ACCOUNTING     CLERK, MANAGER, PRESIDENT
RESEARCH       ANALYST, CLERK, MANAGER
SALES          CLERK, MANAGER, SALESMAN

SQL>

所以，是的 - 首先找到不同的值，然后 listagg 它们。

Answer 2

您可以使用 REGEXP_REPLACE 和 XMLAGG 如下删除重复项：

SQL> with table1(req) as
  2  (SELECT 'TEJASH' FROM DUAL UNION ALL
  3  SELECT 'RIDDHI' FROM DUAL UNION ALL
  4  SELECT 'TEJASH' FROM DUAL UNION ALL
  5  SELECT 'REKHA' FROM DUAL)
  6  SELECT
  7      REGEXP_REPLACE(RTRIM(XMLAGG(XMLELEMENT(E, REQ, ',').EXTRACT('//text()')
  8          ORDER BY
  9              REQ
 10      ).GETCLOBVAL(), ','), '([^,]+)(,)+', '') AS LIST
 11  FROM
 12      TABLE1;

LIST
--------------------------------------------------------------------------------
REKHA,RIDDHI,TEJASH

SQL>

使用 XMLAGG 而不是 LISTAGG 的原因是为了避免任何 4000 个字符的限制问题。

使用 LISTAGG 也可以使用 REGEXP_REPLACE 实现它，如下所示：

SQL> with table1(req) as
  2  (SELECT 'TEJASH' FROM DUAL UNION ALL
  3  SELECT 'RIDDHI' FROM DUAL UNION ALL
  4  SELECT 'TEJASH' FROM DUAL UNION ALL
  5  SELECT 'REKHA' FROM DUAL)
  6  SELECT
  7      REGEXP_REPLACE(
  8          LISTAGG(REQ, ',') WITHIN GROUP(
  9              ORDER BY
 10                  REQ
 11          ), '([^,]+)(,)+', '') AS LIST
 12  FROM
 13      TABLE1;

LIST
--------------------------------------------------------------------------------
REKHA,RIDDHI,TEJASH

SQL>

干杯！！

Listagg 不同值

Listagg distinct values

sql

oracle

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oracle18c