从表中动态提取 XML 元素值的 Oracle 查询

Question

我正在寻找可以在具有存储 XML 的列之一的表上运行的 Oracle 查询 此查询应动态地采用查询中的 xpath 以从所有节点中提取字符串。我在下面尝试过，但我必须对 xpath 进行硬编码。我不想硬编码 xpath。

有没有办法生成 xpath，基于 XML 的结构（结构可能会有所不同）动态提取 xml 节点值？

我需要的输出是xml节点的提取值。

我试过了：

SELECT xmltype(XMLCOLUMN).EXTRACT('/report/fulcriteria/text()'),
       xmltype(XMLCOLUMN).EXTRACT('/report/conumb/text()'),
       xmltype(XMLCOLUMN).EXTRACT('/report/dup/text()'),
       xmltype(XMLCOLUMN).EXTRACT('/report/reportdup[1]/dupsource/text()'),
       xmltype(XMLCOLUMN).EXTRACT('/report/reportdup[2]/dupsource/text()'),
       xmltype(XMLCOLUMN).EXTRACT('/report/reportdup[2]/dupnumb/text()'),
       xmltype(XMLCOLUMN).EXTRACT('/report/reportdup[3]/dupsource/text()'),
       xmltype(XMLCOLUMN).EXTRACT('/report/reportdup[3]/dupnumb/text()') . 
       xmltype(XMLCOLUMN).EXTRACT('/report/final/dup/text()'),
  FROM MYTABLE

Answer 1

将包含动态路径的表与包含 XML 的表连接起来，然后使用 XMLTABLE 提取值：

Oracle 设置：

CREATE TABLE mytable ( id, xmlcolumn ) AS
SELECT 1, '<report>
  <fulcriteria>1</fulcriteria>
  <conumb>2</conumb>
  <dup>3</dup>
  <reportdup><dupsource>4.1</dupsource></reportdup>
  <reportdup><dupsource>4.2a</dupsource><dupnumb>4.2b</dupnumb></reportdup>
  <reportdup><dupsource>4.3a</dupsource><dupnumb>4.3b</dupnumb></reportdup>
  <final><dup>5</dup></final>
</report>' FROM DUAL;

CREATE TABLE paths ( path ) AS
SELECT '/report/fulcriteria' FROM DUAL UNION ALL
SELECT '/report/conumb' FROM DUAL UNION ALL
SELECT '/report/dup' FROM DUAL UNION ALL
SELECT '/report/reportdup[1]/dupsource' FROM DUAL UNION ALL
SELECT '/report/reportdup[2]/dupsource' FROM DUAL UNION ALL
SELECT '/report/reportdup[2]/dupnumb' FROM DUAL UNION ALL
SELECT '/report/reportdup[3]/dupsource' FROM DUAL UNION ALL
SELECT '/report/reportdup[3]/dupnumb'  FROM DUAL UNION ALL
SELECT '/report/final/dup' FROM DUAL;

查询 1：

SELECT t.id,
       p.path,
       x.value
FROM   MYTABLE t
       CROSS JOIN PATHS p
       CROSS JOIN XMLTABLE(
         p.path
         PASSING XMLTYPE( t.xmlcolumn )
         COLUMNS
           value VARCHAR2(4000) PATH '.'
       ) x

查询 2：

SELECT t.id,
       p.path,
       XMLQUERY(
         (p.path || '/text()')
         PASSING XMLTYPE( t.xmlcolumn )
         RETURNING CONTENT
       ) AS value
FROM   MYTABLE t
       CROSS JOIN PATHS p;

查询 3：

SELECT t.id,
       p.path,
       XMLTYPE( t.xmlcolumn ).EXTRACT(p.path||'/text()').getStringVal() AS value
FROM   MYTABLE t
       CROSS JOIN PATHS p;

输出：

身份证 |路径 |价值 -: | :----------------------------- | :---- 1 | /报告/标准 | 1 1 | /报告/conumb | 2 1 | /报告/重复 | 3 1 | /report/reportdup[1]/dupsource | 4.1 1 | /report/reportdup[2]/dupsource | 4.2a 1 | /report/reportdup[2]/dupnumb | 4.2b 1 | /report/reportdup[3]/dupsource | 4.3a 1 | /report/reportdup[3]/dupnumb | 4.3b 1 | /报告/最终/重复 | 5

db小提琴here