如何从postgres中的xml列中选择具有属性的数据

我有以下xml内容：

<?xml version="1.0" encoding="utf-8"?>
<h:html xmlns="http://www.w3.org/2002/xforms" xmlns:ev="http://www.w3.org/2001/xml-events" xmlns:h="http://www.w3.org/1999/xhtml" xmlns:jr="http://openrosa.org/javarosa" xmlns:orx="http://openrosa.org/xforms" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <h:head>
    <h:title>Demo12</h:title>
    <model>
      <instance>
        <uploaded_form_bpdwls id="Demo12">
          <formhub>
            <uuid/>
          </formhub>
          <Household_Number/>
          <Survey_Name/>
          <start/>
          <end/>
          <meta>
            <instanceID/>
          </meta>
        </uploaded_form_bpdwls>
      </instance>
    </model>
  </h:head>
  <h:body>
    <input ref="/uploaded_form_bpdwls/Household_Number">
      <label>Household Number</label>
    </input>
    <input ref="/uploaded_form_bpdwls/Survey_Name">
      <label>Survey Name</label>
    </input>
  </h:body>
</h:html>

在上面的XML内容中

在主体内部，有两个具有不同属性的输入标记，即@ref=/upload\u form\u bpdwls/househouse\u Number

我试图通过postgresSQL选择表格式的数据。我希望房屋保有和调查名称作为单独的列

我不知道如何使用标记的属性选择数据

是否可以在单独的列下选择数据

---

要实现此目的，select查询应该是什么？

这是您想要的吗

with table1 as (
  select $$<?xml version="1.0" encoding="utf-8"?>
 <h:html xmlns="http://www.w3.org/2002/xforms" xmlns:ev="http://www.w3.org/2001/xml-events" xmlns:h="http://www.w3.org/1999/xhtml" xmlns:jr="http://openrosa.org/javarosa" xmlns:orx="http://openrosa.org/xforms" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<h:head>
<h:title>Demo12</h:title>
<model>
  <instance>
    <uploaded_form_bpdwls id="Demo12">
      <formhub>
        <uuid/>
      </formhub>
      <Household_Number/>
      <Survey_Name/>
      <start/>
      <end/>
      <meta>
        <instanceID/>
      </meta>
    </uploaded_form_bpdwls>
  </instance>
</model>
</h:head>
<h:body>
<input ref="/uploaded_form_bpdwls/Household_Number">
  <label>Household Number</label>
</input>
<input ref="/uploaded_form_bpdwls/Survey_Name">
  <label>Survey Name</label>
</input>
 </h:body>
 </h:html>$$::xml as xml_content

 )

 select myarray[1] val1,myarray[2] val2 from (
    select xpath('/h:html/h:body/i:input/i:label/text()',xml_content,ARRAY[ARRAY['h','http://www.w3.org/1999/xhtml'],ARRAY['i','http://www.w3.org/2002/xforms']]) myarray from table1  
 ) a

对于多级别，请尝试以下操作：

        with table1 as (
        select $$<?xml version="1.0" encoding="utf-8"?>
        <h:html xmlns="http://www.w3.org/2002/xforms" xmlns:ev="http://www.w3.org/2001/xml-events" xmlns:h="http://www.w3.org/1999/xhtml" xmlns:jr="http://openrosa.org/javarosa" xmlns:orx="http://openrosa.org/xforms" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
          <h:head>
            <h:title>Demo12</h:title>
            <model>
              <instance>
                <uploaded_form_bpdwls id="Demo12">
                  <formhub>
                    <uuid/>
                  </formhub>
                  <Household_Number/>
                  <Survey_Name/>
                  <start/>
                  <end/>
                  <meta>
                    <instanceID/>
                  </meta>
                </uploaded_form_bpdwls>
              </instance>
            </model>
          </h:head>
          <h:body>
            <div>
            <input ref="/uploaded_form_bpdwls/Household_Number">
              <label>Household Number</label>
            </input>
            <input ref="/uploaded_form_bpdwls/Survey_Name">
              <label>Survey Name</label>
            </input>
            </div>
            <div>
            <input ref="/uploaded_form_bpdwls/Household_Number">
              <label>Household Number2</label>
            </input>
            <input ref="/uploaded_form_bpdwls/Survey_Name">
              <label>Survey Name2</label>
            </input>
            </div>
          </h:body>
        </h:html>$$::xml as xml_content

        )

        select myarray[1] val1,myarray[2] val2 from (
           select xpath('/i:div/i:input/i:label/text()',xml_content,ARRAY[ARRAY['h','http://www.w3.org/1999/xhtml'],ARRAY['i','http://www.w3.org/2002/xforms']]) myarray from 
              (
              select unnest(xpath('/h:html/h:body/i:div',xml_content,ARRAY[ARRAY['h','http://www.w3.org/1999/xhtml'],ARRAY['i','http://www.w3.org/2002/xforms']])) xml_content from table1
              ) div
           ) a

---

我需要您的更多帮助：请解释一下为什么在xpath中使用前缀。。。以及如何将其用于多级数据……因为在xml中，名称空间是定义的：xmlns=用于不带前缀的标记，xmlns:h=用于带前缀h的标记，如果不定义和使用前缀，xpath查询将不返回空arrayRemy，请看一下：