On 8/26/06, Peter Eisentraut <peter_e@gmx.net> wrote:
> Bruce Momjian wrote:
> > Validation
> > ----------
> > /contrib/xml2 has a function called xml_valid() that can be used in
> > a CHECK constraint to enforce that a field contains valid XML. It
> > does not support validation against a specific XML schema.
>
> Then this is not validation but only checking for well-formedness. The
> xml2 README says so, in fact.
Exactly. contrib/xml2 mixes the term here, xml_valid() should be
another function, that takes two types of data - XML value and
corresponding XML schema - and validate the XML data. Actually, the
latest version of SQL/XML standard includes such a function
(XMLVALIDATE).
If you decide to include the mentioning about contrib/xml2 to docs, I
would suggest the patch for this module. The patch renames that
function to xml_check() and adds xml_array() (issue from the current
TODO). Or it's too late for 8.2?
Also, I would add a little introduction to XML terms (from XML
standards) to this documentation section.
--
Best regards,
Nikolay