更改 Oracle 11gR2 的 WM_CONCAT 函数的分隔符
通常,WM_CONCAT 是一个聚合函数,它从像这里这样用逗号分隔的表中返回值.
Normally, WM_CONCAT is an aggregate function that return values from table separated by comma like here.
假设我有一个像这样的表 foo
:
Suppose I have a table foo
like this:
col_id | col_text
111 | This
111 | is
111 | a
111 | test.
如果我使用这个查询:
SELECT CAST(WM_CONCAT(col_text) AS VARCHAR2(100)), col_id FROM foo
结果是
This, is, a, test.
是否可以将 '.'
或 '|'
的分隔符 (','
) 更改为其他字符?code>WM_CONCAT() 函数?
Is it possible to change the separator(','
) to other characters like '.'
or '|'
of the WM_CONCAT()
function?
或者创建一个可以像WM_CONCAT()
那样执行的用户定义函数?
Or create a user defined function that can be executed like WM_CONCAT()
?
推荐答案
您可能想要使用 LISTAGG
.
You might want to use LISTAGG
.
SELECT col_id,
LISTAGG(col_text, '|') WITHIN GROUP (ORDER BY col_text) text
FROM table1
GROUP BY col_id
输出:
| COL_ID | TEXT |
----------------------------
| 111 | This|a|is|test. |
SQLFiddle
UPDATE 如果您需要在列表中获取不同的文本值
UPDATE If you need to get distinct text values in a list
SELECT col_id,
LISTAGG(col_text, '|')
WITHIN GROUP (ORDER BY col_text) text
FROM
(
SELECT DISTINCT col_id, col_text
FROM table1
)
GROUP BY col_id
SQLFiddle
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