Re: PostgreSQL vs SQL/XML Standards

po 12. 11. 2018 v 6:58 odesílatel Markus Winand <markus.winand@winand.at>
napsal:

>
> On 2018-11-9, at 05:07 , Pavel Stehule <pavel.stehule@gmail.com> wrote:
>
>
>
> čt 8. 11. 2018 v 15:18 odesílatel Markus Winand <markus.winand@winand.at>
> napsal:
>
>>
>> > On 2018-11-6, at 15:23 , Pavel Stehule <pavel.stehule@gmail.com> wrote:
>> >
>> >
>> >
>> > po 29. 10. 2018 v 11:45 odesílatel Pavel Stehule <
>> pavel.stehule@gmail.com> napsal:
>> >
>> >
>> > po 29. 10. 2018 v 10:11 odesílatel Pavel Stehule <
>> pavel.stehule@gmail.com> napsal:
>> > Hi
>> >
>> > čt 25. 10. 2018 v 21:47 odesílatel Alvaro Herrera <
>> alvherre@2ndquadrant.com> napsal:
>> > On 2018-Oct-25, Pavel Stehule wrote:
>> >
>> > > I am thinking so I can fix some issues related to XMLTABLE. Please,
>> send me
>> > > more examples and test cases.
>> >
>> > Please see Markus Winand's patch that I referenced upthread.
>> >
>> > here is a fix of some XMLTABLE mentioned issues.
>> >
>> > this update allows cast boolean to numeric types from XPath expressions
>> >
>> > Attached patch solves some cast issues mentioned by Chap. It solves
>> issue reported by Markus. I didn't use Markus's code, but it was
>> inspiration for me. I found native solution from libxml2.
>> >
>> > Regards
>> >
>> > Pavel
>>
>> Better than my patch.
>>
>> But I think the chunk in xml_xmlnodetoxmltype of my patch is still needed
>> — in one way or the other (see below).
>>
>> # select * from xmltable('*' PASSING '<e>pre<!--c1--><?pi
>> arg?><![CDATA[&ent1]]><n2>&amp;deep</n2>post</e>' COLUMNS x XML PATH
>> 'node()');
>>                     x
>> -----------------------------------------
>>  prec1arg&amp;ent1<n2>&amp;deep</n2>post
>> (1 row)
>>
>> Output is not the original XML.
>>
>> I dug a little further and found another case that doesn’t looks right
>> even with my change to xml_xmlnodetoxmltype applied:
>>
>> # select * from xmltable('*' PASSING '<e>pre<!--c1--><?pi
>> arg?><![CDATA[&ent1]]><n2>&amp;deep</n2>post</e>' COLUMNS x XML PATH '/');
>>              x
>> ---------------------------
>>  pre&amp;ent1&amp;deeppost
>> (1 row)
>>
>> Oracle gives in both cases XML.
>>
>> To fix that I included XML_DOCUMENT_NODE in the list of nodes that use
>> xmlNodeDump. Now I wonder if that logic should be reversed to use the
>> xmlXPathCastNodeToString branch in a few selected cases but default to the
>> branch xmlNodeDump for all other cases?
>>
>> I guess those few cases might be XML_ATTRIBUTE_NODE and XML_TEXT_NODE.
>> Regression tests are happy with that approach but I don’t think that proves
>> a lot.
>>
>> -markus
>>
>> diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
>> index 37d85f7..7c1f884 100644
>> --- a/src/backend/utils/adt/xml.c
>> +++ b/src/backend/utils/adt/xml.c
>> @@ -3682,7 +3682,7 @@ xml_xmlnodetoxmltype(xmlNodePtr cur,
>> PgXmlErrorContext *xmlerrcxt)
>>  {
>>         xmltype    *result;
>>
>> -       if (cur->type == XML_ELEMENT_NODE)
>> +       if (cur->type != XML_ATTRIBUTE_NODE && cur->type != XML_TEXT_NODE)
>>         {
>>                 xmlBufferPtr buf;
>>                 xmlNodePtr      cur_copy;
>>
>>
> I used your patch and append regress tests. I checked the result against
> Oracle.
>
> Regards
>
> Pavel
>
>
> Fine from my side.
>

super

Thank you for investigation and tests, examples.

It is assigned to January commitfest.

Regards

Pavel


> -markus
>
>