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[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] RE: XQuery and DTD/Schema?
 The input to an XQuery query consists of (at compile time) a set of type definitions and (at run time) a set of documents/trees with type annotations. The set of type definitions can be empty, and the type annotations can be defaulted, so queries can therefore be written against documents that have not been subjected to schema processing. The XQuery working group has only recently started work on conformance statements. There is a draft proposal on the table that defines a conformance level for implementations that don't support schema processing - in other words, such implementations don't handle type definitions or type annotations. Whether this proposal makes it into the next draft depends more (I think) on getting the detail right than on any differences about the principle. Of course it's also possible that some vendors will want to impose stronger constraints, for example that all the documents in the scope of a single query conform to the same schema. Presumably people who don't like such a constraint won't buy the product... As far as the XQuery spec is concerned, although the type system is chosen to be compatible with XML Schema, there is no requirement for the type definitions and type annotations actually to be produced by XML Schema processing (just as XSLT can process a source tree that wasn't created by parsing source XML). I hope this goes some way to answering the question. Michael Kay Software AG home: Michael.H.Kay@n... work: Michael.Kay@s... > -----Original Message----- > From: Betty Harvey [mailto:harvey@e...] > Sent: 02 July 2002 23:51 > To: xml-dev@l... > Subject: XQuery and DTD/Schema? > > > > I haven't been following the progress of XQuery closely. I > was advised today that a W3C Schema had to be developed > instead of a DTD because XQuery only works with Schema. I > was skeptical that the XQuery specification would really say > this. However, I found what I believe to be conflicting > information in the XQuery specification: > > "XQuery's type system is based on [XML Schema]. Work is in > progress to > ensure that the type systems of XQuery, the XQuery Core, > and XML Schema > are completely aligned." > > I interpret the above statement to mean that XQuery datatypes > will be based upon XML Schema. I believe this statement may > be the reason for others thinking that an XML Schema and not > DTD's or RELAX NG was required in order to use XQuery. > > Any thoughts on my interpretation of the specification. Thanks! > > Betty > > /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/ > Betty Harvey | Phone: 410-787-9200 FAX: 9830 > Electronic Commerce Connection, Inc. | > harvey@e... | Washington,DC SGML/XML > Users Grp > URL: http://www.eccnet.com | http://www.eccnet.com/xmlug/ > /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\\/\/ > > > > ----------------------------------------------------------------- > The xml-dev list is sponsored by XML.org > <http://www.xml.org>, an initiative of OASIS <http://www.oasis-open.org> The list archives are at http://lists.xml.org/archives/xml-dev/ To subscribe or unsubscribe from this list use the subscription manager: <http://lists.xml.org/ob/adm.pl> 
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