XMLSequence and extract attribute

Question

Hi all,
From this XML :
<execute-transaction app-ref="SRSRSimpleMult" app-sn="458" login="CARNI">
     <context key="Env:LOGIN" value="CARNI"/>
     <context key="Env:APP_SN" value="458"/>
     <context key="Env:APP_REF" value="SRSRSimpleMult"/>
</execute-transaction>I would like to extract all the "key" attribute...
The following select returns the good result but all is in 1 row :
select extract(XMLTYPE('<execute-transaction app-ref="SRSRSimpleMult" app-sn="458" login="CARNI">
     <context key="Env:LOGIN" value="CARNI"/>
     <context key="Env:APP_SN" value="458"/>
     <context key="Env:APP_REF" value="SRSRSimpleMult"/>
</execute-transaction>'),'*/context/@key') FROM DUAL;So I use XMLSequence (and not XMLTable because I'm still on Oracle 10g1) but the following select returns nothing
select COLUMN_VALUE FROM table(xmlsequence(extract(XMLTYPE('<execute-transaction app-ref="SRSRSimpleMult" app-sn="458" login="CARNI">
     <context key="Env:LOGIN" value="CARNI"/>
     <context key="Env:APP_SN" value="458"/>
     <context key="Env:APP_REF" value="SRSRSimpleMult"/>
</execute-transaction>'),'*/context/@key')));However if I simply remove the "@key" in the XPath expression, the select gives me back a good result ! (but with the context tag that I don't care)
Can someone tell me why the SELECT doesn't return a result when the xpath expression contains the "@key" attribute ?
Thx

Answer 1

select xt.*
FROM  table(xmlsequence(extract(XMLTYPE
                    ('<execute-transaction app-ref="SRSRSimpleMult" app-sn="458" login="CARNI">
                        <context key="Env:LOGIN" value="CARNI"/>
                        <context key="Env:APP_SN" value="458"/>
                        <context key="Env:APP_REF" value="SRSRSimpleMult"/>
                      </execute-transaction>')
                               , '/execute-transaction/context'))) xt;
COLUMN_VALUE
<context key="Env:LOGIN" value="CARNI"/>
<context key="Env:APP_SN" value="458"/>
<context key="Env:APP_REF" value="SRSRSimpleMult"/>
3 rows selected
select rownum as "ROW"
     , extract(value(xt),'/context/@key') as "RESULT"
FROM   table(xmlsequence(extract(XMLTYPE
                     ('<execute-transaction app-ref="SRSRSimpleMult" app-sn="458" login="CARNI">
                         <context key="Env:LOGIN" value="CARNI"/>
                         <context key="Env:APP_SN" value="458"/>
                         <context key="Env:APP_REF" value="SRSRSimpleMult"/>
                        </execute-transaction>')
                                 , '/execute-transaction/context'))) xt;
ROW RESULT
  1 Env:LOGIN
  2 Env:APP_SN
  3 Env:APP_REF
3 rows selectedEdited by: Marco Gralike on Mar 30, 2011 12:43 PM