Re: XPATH evaluation - Mailing list pgsql-hackers

From Andrew Dunstan
Subject Re: XPATH evaluation
Date
Msg-id 4DFB5AD8.3030705@dunslane.net
Whole thread Raw
In response to Re: XPATH evaluation  (Florian Pflug <fgp@phlo.org>)
Responses Re: XPATH evaluation
List pgsql-hackers

On 06/17/2011 05:41 AM, Florian Pflug wrote:
> On Jun17, 2011, at 11:09 , Radosław Smogura wrote:
>> 1.
>> SELECT (XPATH('/root/*', '<root xmlns:o="http://olacle.com/db"
xmlns:p="http://postgresql.org/db"><o:db><a><b></b></a></o:db><p:db></p:db></root>'));
>> Produces:
>> "{"<o:db>
>>   <a>
>>     <b/>
>>   </a>
>> </o:db>",<p:db/>}"
>> In above<b></b>  was reduced to<b/>  this is different infoset then input, and those notations are differently
interpretede.g. by XML Binding&  WebServices. The 1st one will may be mapped to empty string, and 2nd one to to null. 
> Oh, joy :-(

I thought these were basically supposed to be the same.

The XML Information Set for example specifically excludes:

    The difference between the two forms of an empty element: |<foo/> |
    and |<foo></foo>|.||||

|
See <http://www.w3.org/TR/2004/REC-xml-infoset-20040204/> Appendix D.
Note that this implies that <foo></foo> does not have content of an
empty string, but that it has no content.

|
cheers

andrew


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