Question

可能重复：
How can I combine multiple rows into a comma-delimited list in Oracle?

有人可以告诉我如何实现以下目标吗？

表：

efforts_id        cycle_name      release_name 
123               quarter         march 
123               half            april 
123               full            april
124               quarter         may

我的预期输出：

efforts_id        cycle_name            release_name 
123               quarter,half,full     march,april
124               quarter               may

我是oracle的初学者所以不确定如何做到这一点。任何帮助将不胜感激。

由于

Answer 1

您需要的是“字符串聚合”。 Tim Hall的优秀网站根据您拥有的Oracle的确切版本显示您拥有的替代方案：http://www.oracle-base.com/articles/misc/string-aggregation-techniques.php

在11gR2（写作时的当前）中，您应该使用listagg函数：

select
  efforts_id,
  listagg(cycle_name, ',') within group (order by cycle_name) as cycle_name,
  listagg(release_name, ',') within group (order by release_name) as release_name
from my_table
group by efforts_id;

请注意，Oracle不支持使用wm_concat函数...

Answer 2

您需要使用LISTAGG()来执行此任务。其他答案不删除任何重复值，删除重复项，您可以使用类似的东西：

select c.efforts_id, 
  c.cycle_name,
  listagg(r.release_name, ', ') within group (order by c.efforts_id) as release_name
from
(
  select efforts_id,
    listagg(cycle_name, ', ') within group (order by efforts_id) as cycle_name
  from yourtable
  group by efforts_id
) c
inner join
(
  select distinct efforts_id, release_name
  from yourtable
) r
  on c.efforts_id = r.efforts_id
group by c.efforts_id, c.cycle_name

请参阅SQL Fiddle with Demo

Answer 3

如果你有Oracle 11g R2，那么LISTAGG是首选的方法：

SELECT efforts_id,
    LISTAGG(cycle_name) WITHIN GROUP(ORDER BY cycle_name),
    LISTAGG(release_name) WITHIN GROUP(ORDER BY cycle_name)
FROM MY_TABLE
GROUP BY efforts_id

如果没有，this article会显示其他方法。

Answer 4

通过WM_concat函数（当然还有GROUP BY）

SELECT efforts_id, wm_concat(cycle_name), wm_concat(release_name)
FROM MY_TABLE
GROUP BY efforts_id

嗯，刚刚发现了这个：

请注意， WM_CONCAT 未记录且不受支持，这意味着它不应在生产系统中使用 LISTAGG 功能可以产生与 WM_CONCAT 相同的输出，并由Oracle记录和支持。

Oracle用逗号连接列

4 个答案: