Oracle:归一化为CSV字符串的字段 [英] Oracle: normalized fields to CSV string

问题描述

我有一些这样的归一化数据.

I have some one-many normalized data that looks like this.

a | x
a | y
a | z
b | i
b | j
b | k

哪个查询将返回数据，以便将许多"面表示为CSV字符串?

What query will return the data such that the "many" side is represented as a CSV string?

a | x,y,z
b | i,j,k

推荐答案

标记，

如果您使用的是11gR2版本，但不是:-)，则可以使用listagg

If you are on version 11gR2, and who isn't :-), then you can use listagg

SQL> create table t (col1,col2)
  2  as
  3  select 'a', 'x' from dual union all
  4  select 'a', 'y' from dual union all
  5  select 'a', 'z' from dual union all
  6  select 'b', 'i' from dual union all
  7  select 'b', 'j' from dual union all
  8  select 'b', 'k' from dual
  9  /

Tabel is aangemaakt.

SQL> select col1
  2       , listagg(col2,',') within group (order by col2) col2s
  3    from t
  4   group by col1
  5  /

COL1  COL2S
----- ----------
a     x,y,z
b     i,j,k

2 rijen zijn geselecteerd.

如果您的版本不是11gR2，但高于10gR1，那么我建议为此使用模型子句，如下所示:

If your version is not 11gR2, but higher than 10gR1, then I recommend using the model clause for this, as written here: http://rwijk.blogspot.com/2008/05/string-aggregation-with-model-clause.html

如果低于10，则可以在rexem到oracle-base页面的链接中，或在上述博文中的OTN线程的链接中看到几种技术.

If lower than 10, then you can see several techniques in rexem's link to the oracle-base page, or in the link to the OTN-thread in the blogpost mentioned above.

关于， 罗布.

这篇关于Oracle:归一化为CSV字符串的字段的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！