PL/SQL-选择列值作为字符串数组

我不确定以前是否有人问过这个问题。我也不知道该怎么说。但我会用一个场景来解释。
我有以下表格
带列的选项卡1：用户ID、代码、国家/地区
带列的选项卡2：用户ID、代码、电子邮件

示例内容：

TAB1:
RISHI, A1B2C3, INDIA
RISHI, D2E3F4, INDIA
KANTA, G3H4I5, INDONESIA

TAB2:
RISHI, A1B2C3, rishi1@test.com
RISHI, A1B2C3, rishi2@test.com
RISHI, A1B2C3, rishi3@test.com
RISHI, D2E3F4, rishi1@test.com
RISHI, D2E3F4, rishi2@test.com
KANTA, G3H4I5, kanta1@test.com

我希望从select查询或pl/sql存储过程得到如下结果：

RISHI, INDIA, A1B2C3, (rishi1@test.com, rishi2@test.com, rishi3@test.com)
RISHI, INDIA, D2E3F4, (rishi1@test.com, rishi2@test.com)

如果我做了如下选择：

select a.userid, a.code, a.country, b.email
from tab1.a, tab2.b
where a.userid = b.userid
and a.code = b.code
and a.userid = 'RISHI';

我得到的结果如下：

RISHI, INDIA, A1B2C3, rishi1@test.com
RISHI, INDIA, A1B2C3, rishi2@test.com
RISHI, INDIA, A1B2C3, rishi3@test.com
RISHI, INDIA, D2E3F4, rishi1@test.com
RISHI, INDIA, D2E3F4, rishi2@test.com

---

我基本上需要的是将电子邮件ID组合成一个数组。假设TAB1包含更多我实际需要的列，但在本例中我省略了这些列，但是TAB2只有这三列。

我认为您希望在MySQL中使用

GROUP\u CONCAT

聚合函数。坏消息是Oracle没有用于组合并的内置功能，好消息是您可以模拟这样的功能

请看这个片段：

with data
     as
     (
          select job,
                ename,
                row_number() over (partition by job order by ename) rn,
                count(*) over (partition by job) cnt
      from emp
     )
 select job, ltrim(sys_connect_by_path(ename,','),',') scbp
  from data
  where rn = cnt
  start with rn = 1
  connect by prior job = job and prior rn = rn-1
  order by job

而且还会回来

JOB       SCBP
--------- ----------------------------------------
ANALYST   FORD,SCOTT
CLERK     ADAMS,JAMES,MILLER,SMITH
MANAGER   BLAKE,CLARK,JONES
PRESIDENT KING
SALESMAN  ALLEN,MARTIN,TURNER,WARD

---

我们发现这只在Oracle 11g第2版中可用，我们使用的是第1版。谢天谢地，我的要求已经改变了，我不再需要这个了。但这是一件非常有用的事情。谢谢

select a.userid, a.code, a.country, listagg(b.email, ',') within group (order by b.email) as "Emails"
from tab1.a, tab2.b
where a.userid = b.userid
and a.code = b.code
and a.userid = 'RISHI'
group by a.userid, a.code, a.country;