pr@paulrichards.me.uk wrote:
Is it possible to use an XML Schema to ensure that the data in one
attribute is less than or equal to the value in another?
Is it possible, through the use of the <xsd:sequenceor similar, to
ensure than a multiplicity is equal to the value held in another
attribute?
No, and no. Cross-validation constraints are not currently handled by
XML Schema with the exception of key/keyref and id/idref. Implement
those in your application code. Think of schema as higher-level syntax
constraints; your application is responsible for semantics.
(Some of the alternative schema languages do support cross-constaints,
but of course those have the issue of not being as widely supported or,
in some sense, as "official". Rumor has it that a future version of XML
Schema is considering picking up some of those capabilites, but I don't
know how real that is or what its status might be.)
--
Joe Kesselman / Beware the fury of a patient man. -- John Dryden