Oracle listagg-我可以根据listagg选择的值从其他表中提取数据

如何解决Oracle listagg-我可以根据listagg选择的值从其他表中提取数据

我有两个表，并希望根据第二个表中Listtagg的值从一个表中获取数据：

T1
ID     Name
==============
1      Name1
2      Person2
3      Someone3
4      Mr.4

T2
ID     Acct
===============
1      1234
1      5678
2      1234
3      5678
3      8769
4      1234

我在T2上的listagg查询返回了以下内容：

Acct   Id
====== ========
1234   1,2,4
5678   1,3

我需要其他表中带有Names的结果，例如：

Acct   Id       Name
====== ======== ==========
1234   1,4    Name1,Person2,Mr.4
5678   1,3      Name1,Someone3

解决方法

您为什么要先汇总ID，然后将其拆分以收集NAME？立即做。并不是说它不能完成（它可以以相对简单的方式，但是-为什么？！？）。

样本数据来自第1-15行；查询可能从第16行开始。

SQL> with
  2  t1 (id,name) as
  3    (select 1,'Name1' from dual union all
  4     select 2,'Person2' from dual union all
  5     select 3,'Someone3' from dual union all
  6     select 4,'Mr4' from dual
  7    ),8  t2 (id,acct) as
  9    (select 1,1234 from dual union all
 10     select 1,5678 from dual union all
 11     select 2,1234 from dual union all
 12     select 3,5678 from dual union all
 13     select 3,8769 from dual union all
 14     select 4,1234 from dual
 15    )
 16  select b.acct,17    listagg(b.id,',') within group (order by b.id) id,18    listagg(a.name,') within group (order by b.id) name
 19  from t1 a join t2 b on a.id = b.id
 20  group by b.acct;

      ACCT ID         NAME
---------- ---------- --------------------
      1234 1,2,4    Name1,Person2,Mr4
      5678 1,3       Name1,Someone3
      8769 3          Someone3

SQL>

,

@Littlefoot的答案是绝对正确的。但请注意：如果要拆分这些汇总值，请不要使用listagg。只需使用collect()聚合函数即可将所需数据作为集合。 例如：

select 
   cast(collect(level) as sys.odcinumberlist) as varray_of_numbers,cast(collect(level) as ORA_MINING_NUMBER_NT) as nested_table_of_numbers,cast(collect(sys.ku$_objnum(level)) as sys.KU$_OBJNUMSET) as nested_table_of_objnum
from dual connect by level<=3;

--Result:
VARRAY_OF_NUMBERS         NESTED_TABLE_OF_NUMBERS        NESTED_TABLE_OF_OBJNUM(OBJ_NUM)
------------------------- ------------------------------ ------------------------------------------------------------
ODCINUMBERLIST(1,3)   ORA_MINING_NUMBER_NT(1,3)  KU$_OBJNUMSET(KU$_OBJNUM(1),KU$_OBJNUM(2),KU$_OBJNUM(3))

更新：这是对表的查询，如您在注释中所要求的：

select b.acct,cast(collect(b.id) as ORA_MINING_NUMBER_NT) as nested_table_of_numbers,cast(collect(a.name) as ORA_MINING_VARCHAR2_NT) as nested_table_of_varchar2
--  listagg(b.id,--  listagg(a.name,') within group (order by b.id) name
from t1 a join t2 b on a.id = b.id
group by b.acct;

完整示例：

with
t1 (id,name) as
  (select 1,'Name1' from dual union all
   select 2,'Person2' from dual union all
   select 3,'Someone3' from dual union all
   select 4,'Mr4' from dual
  ),t2 (id,acct) as
  (select 1,1234 from dual union all
   select 1,5678 from dual union all
   select 2,1234 from dual union all
   select 3,5678 from dual union all
   select 3,8769 from dual union all
   select 4,1234 from dual
  )
select b.acct,') within group (order by b.id) name
from t1 a join t2 b on a.id = b.id
group by b.acct;