如何从字符串中提取html结构？答案

【问题标题】：How to extract html structure from string?如何从字符串中提取html结构？
【发布时间】：2021-12-12 13:59:40
【问题描述】：

我有一个用 html 写的长文本：

<body>
    <h2>title 1</h2>
    <h2>This is an <b>important</b> title</h2>
        Some text
        <h3>This a subtitle b</h3>
        <h3>This is also <span style="font-weight:500">important</span></h3>        
</body>

我需要从中提取标题以创建目录。我希望结果为：

h2      Title 1
h2      This is an <b>important</b> title
h3      This a subtitle b
h3      This is also <span style="font-weight:500">important</span>

或

h2      Title 1
h2      This is an important title
h3      This a subtitle b
h3      This is also important

我试过了

select * from xmltable('body/*'  passing xmltype('<body><h2>title 1</h2><h2>This is an <b>important</b> title</h2>Some text<h3>This a subtitle b</h3><h3>This is also <span style="font-weight:500">important</span></h3></body>') 
columns 
tag_name varchar2(1000) path 'name()',
tag_value varchar2(1000) path 'text()')
where tag_name in ('h1','h2','h3','h4','h5')

但我得到了错误：

ORA-19279: XPTY0004 - XQuery dynamic type mismatch: expected singleton sequence - got multi-item sequence
19279. 00000 -  "XPTY0004 - XQuery dynamic type mismatch: expected singleton sequence - got multi-item sequence" 
*Cause:    The XQuery sequence passed in had more than one item.
*Action:   Correct the XQuery expression to return a single item sequence.

请问有人知道怎么解决吗？

谢谢。

【问题讨论】：

标签： html oracle plsql

【解决方案1】：

这可以作为输出吗？

TAG_NAME TAG_VALUE                                                             
-------- ----------------------------------------------------------------------
h2       <h2>title 1</h2>                                                      
h2       <h2>This is an <b>important</b> title</h2>                            
h3       <h3>This a subtitle b</h3>                                            
h3       <h3>This is also <span style="font-weight:500">important</span></h3>

这对我来说更有意义 - 然后让您使用的任何 xml 工具根据需要解释标记值。（他们可能要求标签值是 xmltype 数据类型 - 如果是这样，那么只需删除 select 子句中的 xmlserialize 包装器。）

如果可以接受，您可以通过对查询稍作修改来获得它。

select tag_name, xmlserialize(document tag_value) as tag_value
from xmltable('body/*'  passing xmltype('<body><h2>title 1</h2>
  <h2>This is an <b>important</b> title</h2>Some text<h3>This a subtitle b</h3>
  <h3>This is also <span style="font-weight:500">important</span></h3></body>') 
columns 
  tag_name varchar2(1000) path 'name()',
  tag_value xmltype path '.')
where tag_name in ('h1','h2','h3','h4','h5')
;

【讨论】：