Using table() in select , select .... from .... table( ) where ....

Question

Hi Folks,
I hope someone out there can help me out with this one. It has me stumped:
Basically we have an XML document stored in an XMLType which we need to process relationally.
I have the following cursor definition:
CURSOR c_section13h(cp_jsatfa_xml_id IN NUMBER) IS
   SELECT
     jx.JSATFA_ID
     ,to_number(jx.jsatfa_xml_id)
     ,extractvalue( value(t), '/Email ')    as "EMAIL"
   FROM jsatfa_xml jx
     ,table ( xmlsequence (extract (jx.xml_doc, '/document/Section13/Accommodation/Row/Email'))) t
    WHERE jx.jsatfa_xml_id = cp_jsatfa_xml_id;This returns:
jx.jsatfa_id, jx.jsatfa_xml_id, Email1
jx.jsatfa_id, jx.jsatfa_xml_id, Email2
jx.jsatfa_id, jx.jsatfa_xml_id, Email3
jx.jsatfa_id, jx.jsatfa_xml_id, Email4
This in itself works. However I would like to pull out a second item (e.g. Telephone) from the xml_document in the form:
jx.jsatfa_id, jx.jsatfa_xml_id, Email1, Telephone1
jx.jsatfa_id, jx.jsatfa_xml_id, Email2, Telephone2
jx.jsatfa_id, jx.jsatfa_xml_id, Email3, Telephone3
jx.jsatfa_id, jx.jsatfa_xml_id, Email4, Telephone4
At present I have to use a second cursor to process the second entry. This is because is is not possible to have more than one table() definition in the from clause as Cartesian products result. I.E the following causes a cartesian:
CURSOR c_section13h(cp_jsatfa_xml_id IN NUMBER) IS
   SELECT
     jx.JSATFA_ID
     ,to_number(jx.jsatfa_xml_id)
     ,extractvalue( value(t), '/Email ')    as "EMAIL"
     ,extractvalue( value(t1), '/Telephone')    as "TELEPHONE"
   FROM jsatfa_xml jx
     ,table ( xmlsequence (extract (jx.xml_doc, '/document/Section13/Accommodation/Row/Email'))) t
     ,table ( xmlsequence (extract (jx.xml_doc, '/document/Section13/Accommodation/Row/Telephone'))) t1
    WHERE jx.jsatfa_xml_id = cp_jsatfa_xml_id;The specific XML data is tabular data (i.e. its square). Currently I am processing each column (e.g. email, telephone) with a separate cursors.
Ideally I'd like to be able to place the jsatfa_id and jsatfa_xml_id within the table( ) clause so that they can be joined without creating Cartesian products. These IDs are not in the xml.
Does anyone have any ideas
I hope this makes sense, if it doesn't please let me know.
- Kris
http://kristianjones.blogspot.com
Message was edited by:
Kris Jones
Message was edited by:
Kris Jones

Answer 1

Here is one way to do that:
michaels>  WITH jsatfa_xml AS
     (SELECT 1 jsatfa_xml_id, XMLTYPE
<document>
<Section13>                                       
  <Accommodation>                                             
  <Row>                                           
    <TelephoneNumber>telnum</TelephoneNumber>       
    <TelephoneNumber>telnum2</TelephoneNumber>       
    <TelephoneNumber />                             
    <TelephoneNumber />                             
    <TelephoneNumber />                             
  </Row>                                          
  <Row>                                           
    <Email>[email protected]</Email>                  
    <Email />                                       
    <Email />                                       
    <Email />                                       
    <Email />                                       
  </Row>                                          
  <Row>                                           
     <Comments>no comment</Comments>                 
     <Comments />                                    
     <Comments />                                    
     <Comments />                                    
     <Comments />                                    
  </Row>                                          
  </Accommodation>
  <Row>
  </Row>      
  <Row>
  </Row>            
</Section13>   
</document>'
                ) xml_doc
        FROM DUAL)
---  End Test XML
SELECT jsatfa_xml_id, email, phone
  FROM jsatfa_xml t,
       XMLTable('Email' PASSING EXTRACT(xml_doc,'/document/Section13/Accommodation/Row/Email')
                        COLUMNS  POS FOR ORDINALITY,
                                 EMAIL VARCHAR2(30) PATH 'node()'
                ) t2,
       XMLTable('TelephoneNumber' PASSING EXTRACT(xml_doc,'/document/Section13/Accommodation/Row/TelephoneNumber')
                        COLUMNS  POS   FOR ORDINALITY,
                        PHONE VARCHAR2(30) PATH 'node()'
               ) t3   
WHERE t2.pos = t3.pos
   AND jsatfa_xml_id = 1
                                     JSATFA_XML_ID EMAIL                          PHONE                        
                                                 1 [email protected]                telnum                       
                                                 1                                telnum2                      
                                                 1                                                             
                                                 1                                                             
                                                 1                                                             
5 rows selected.