Postgres JSONb 包括带有键值和值的 XML 数组 [英] Postgres JSONb including array to XML with key and value and value

问题描述

我有一个表格如下:

id  (VARCHAR) | field1 (text) | attributes  (jsonb)     
--------------+---------------+----------------------------------

 123          |   a           |   {"age": "1", "place": "TX"}                 
 456          |   b           |   {"age": "2", "name": "abcdef"}     
 789          |               |       
 098          |   c           |   {"name": ["abc", "def", "ghi"]}     

想将其转换为:

 <Company id="123" field="a">
      <CompanyTag tagName="age" tagValue="1"/>
      <CompanyTag tagName="place" tagValue="TX"/>
 </Company>
 <Company id="456" field="b">
      <CompanyTag tagName="age" tagValue="2"/>
      <CompanyTag tagName="name" tagValue="abcdef"/>
 </Company>
 <Company id="789"/>
  <Company id="098" field="c">
      <CompanyTag tagName="name" tagValue="abc"/>
      <CompanyTag tagName="name" tagValue="def"/>
      <CompanyTag tagName="name" tagValue="ghi"/>
 </Company>

在@bergi 和@Georges Martin 的帮助下Post 能够使用以下查询转换非数组:

With help of @bergi and @Georges Martin under Post was able to convert the non array using below query:

SELECT XMLELEMENT(
  NAME "Company", 
  XMLATTRIBUTES(id AS id, field1 AS field), 
  (SELECT XMLAGG(
    XMLELEMENT(
      NAME "companyTag", 
      XMLATTRIBUTES(
        attr.key AS "tagName", 
        attr.value AS "tagValue"
      )
    )
  ) FROM JSONB_EACH_TEXT(attributes) AS attr)
) FROM comp_emp;

但是数组值显示如下:

 <Company id="098" field="c">
      <CompanyTag tagName="name"tagValue="[&quot;abc&quot;, &quot;def&quot;, &quot;ghi&quot;]"/> 

我不想在查询中特别提及键(tagName")，因为这可能会有所不同.假设这是由于 JSONB_EACH_TEXT 提取最外层值引起的.有没有替代品?

I do not want to mention the key ("tagName") specifically in the query as this may vary. Assuming that this is caused due to JSONB_EACH_TEXT extracting the outermost values. Is there an alternative?

请引导我走向正确的方向.

Please guide me in the right direction.

推荐答案

如果您正在处理数组，则需要额外的 jsonb_array_elements_text 来提取值.使用横向连接完成:

You'll need an extra jsonb_array_elements_text extracting the values if you're dealing with an array. Done with a lateral join:

SELECT XMLAGG(
  XMLELEMENT(
    NAME "CompanyTag", 
    XMLATTRIBUTES(
      attr.key AS "tagName", 
      values.element AS "tagValue"
    )
  )
) FROM jsonb_each(attributes) AS attr,
LATERAL jsonb_array_elements_text(CASE jsonb_typeof(attr.value)
  WHEN 'array' THEN attr.value
  ELSE jsonb_build_array(attr.value)
END) AS values(element)

^{(在线演示，附完整查询)}

^{(online demo, with complete query)}

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