From XML to list of paths in Oracle PL/SQL environment

Question

Please suppose you have a XML file (stored, for example, in an Oracle table which has also a CLOB column):

<ALFA>
  <BETA>0123</BETA>
  <GAMMA>2345</GAMMA>
  <DELTA>
     <EPSILON>3</EPSILON>
  </DELTA>
</ALFA>

How can I produce, in output, the list of all possible paths?

/ALFA/BETA/text()
/ALFA/GAMMA/text()
/ALFA/DELTA/EPSILON/text()

My need is the following: I have to EXTRACT many information from a long XML and I have to use XMLEXTRACT with all possible paths, so I would like to know if is it possible to "dbms_output.put_line" them in an automatic way.

I need a solution which is independent from the name of the tags.

Please suppose that the XML is well-formed.

Thank you in advance for your kind help.

---

• In second instance:

---

How can I proceed if Oracle Java Extension has not been installed, and I receive the following error?

ORA-19112: error raised during evaluation:  
ORA-06550: line 1, column 13:
PLS-00201: identifier 'SYS.DBMS_XQUERYINT' must be declared
ORA-06550: line 1, column 7:
PL/SQL: Statement ignored

Please suppose that I am not DBA, and DBA don't authorize Oracle Java Extension installation.

Answer 1

You can use XMLTable to produce list of paths with XQuery.

E.g.

(SQLFiddle)

with params as (
  select 
    xmltype('
      <ALFA>
        <BETA>0123</BETA>
        <GAMMA>2345</GAMMA>
        <DELTA>
           <EPSILON>3</EPSILON>
        </DELTA>
      </ALFA>
    ') p_xml
  from dual  
)    
select
  path_name || '/text()'
from
  XMLTable(
    '
      for $i in $doc/descendant-or-self::*
        return <element_path> {$i/string-join(ancestor-or-self::*/name(.), ''/'')} </element_path>
    '
    passing (select p_xml from params) as "doc"
    columns path_name varchar2(4000) path '//element_path'
  )

but it's a wrong way at least because it's not effective as it can.

Just extract all values with same XQuery: (SQLFiddle)

with params as (
  select 
    xmltype('
      <ALFA>
        <BETA>0123</BETA>
        <GAMMA>2345</GAMMA>
        <DELTA>
           <EPSILON>3</EPSILON>
        </DELTA>
      </ALFA>
    ') p_xml
  from dual  
)    
select
  element_path, element_text
from
  XMLTable(
    '              
      for $i in $doc/descendant-or-self::*
        return <element>
                 <element_path> {$i/string-join(ancestor-or-self::*/name(.), ''/'')} </element_path>
                 <element_content> {$i/text()}</element_content>
               </element>  
    '
    passing (select p_xml from params) as "doc"
    columns 
      element_path   varchar2(4000) path '//element_path',
      element_text   varchar2(4000) path '//element_content'
  )