Updatexml function is returning error. Syntax problem....

Question

I have a xmlfile which is shown below...
cat MYTEMP.xml
<?xml version="1.0" encoding = "AL32UTF8"?>
<ROWSET>
<ROW>
<EDETAIL>test</EDETAIL>
<T1>3</T1>
</ROW>
<ROW>
<EDETAIL> test1</EDETAIL>
<T1>4</T1>
</ROW>
<ROW>
<EDETAIL>test2 </EDETAIL>
<T1>2</T1>
</ROW>
<ROW>
<EDETAIL> </EDETAIL>
<T1>1</T1>
</ROW>
<ROW>
<EDETAIL> </EDETAIL>
<T1>5</T1>
</ROW>
</ROWSET>
I load this xmlfile into a xmltype column in a global temporary table.
I have to update edetail tag to '~:' if it contains only whitespace(s) in it.
I am trying the following command and its giving me error....
insert into gt_xmltype_tab(xmlfile1)
values(XMLType(bfilename('RESTOREDIR','MYTEMP.xml'),nls_charset_id('AL32UTF8')));
update gt_xmltype_tab set xmlfile1 = updatexml(xmlfile1, '/ROWSET/ROW/EDETAIL/text()','~:')
where extractvalue(xmlfile1, '/ROWSET/ROW/EDETAIL') IS NULL
I get the following error for the updatexml...
update gt_xmltype_tab set XMLFILE1 = updatexml(XMLFILE1 , '/ROWSET/ROW/EDETAIL/text()','~:')
ERROR at line 1:
ORA-19025: EXTRACTVALUE returns value of only one node
What is the correct way of doing it? What am I doing wrong?

Answer 1

What is the correct way of doing it? What am I doing wrong?The WHERE clause filters records from the table, not repeating elements from the XML document.
Actually, I'm not sure if you want one or the other...
If you've got multiple XML files in the table, and want to update (the table) only where there's something to update, then use existsNode in the WHERE clause to check if the XML possesses at least an "empty" element.
If there's only one XML in the table, no WHERE clause necessary.
As for the update (of the XML document), that's a little tricky.
Once into the table, whitespaces are not preserved, so there's actually no text() node to update.
A solution is to update the element as a whole :
UPDATE gt_xmltype_tab
SET xmlfile1 = updateXML( xmlfile1
                        , '/ROWSET/ROW/EDETAIL[not(text())]'
                        , XMLElement("EDETAIL", '~:') )
;