Question

我如何将多个行的数据合并为一个表格,合并为一个新表格的单列一栏?

create table new_paragraphs
(
    id NUMBER
    paragraph CLOB
);

create table old_paragraphs
(
   id
   paragraph CLOB
);

merge into new_paragraphs  a
using (select * from old_paragraphs) b
on (id = id)
when matched then
update set a.paragraph = a.paragraph || b.paragraph;
-- Results in error: unable to get a stable set of rows in the source tables

以上只是一个例外。

Answer 1

如果<代码>id,该编码将有效。至少是* 旧第*段的主要关键内容(或者,对于在*新第*段中发现的每名助手来说,这是独一无二的)。

除此以外,请在<代码>on (id = id)上使用别名,以便读到on(a.id = b.id):

merge into new_paragraphs  a
using (select * from old_paragraphs) b
on (a.id = b.id)
when matched then
update set a.paragraph = a.paragraph || b.paragraph;

Answer 2

为什么你们在这里做一个<条码>。为什么不简单的<代码>UPDATE(假设ID是两个表格的主要关键)

UPDATE new_paragraphs a
   SET paragraph = (select a.paragraph || b.paragraph
                      from old_paragraphs b
                     where a.id = b.id)
 WHERE EXISTS (SELECT 1
                 FROM old_paragraphs b
                WHERE a.id = b.id)

友情链接