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From: Pavel Velikhov <pvelikho@c...> >Rick Jelliffe wrote: >> >> >> From: Pavel Velikhov <pvelikho@c...> >> >> >If you don't know whether the object you are picking is an >> >attribute or an element, you will have to write a disjunction. >> >> When don't you know whether an object you are picking is an >> attribute or an element? >> >> Rick Jelliffe > >When you are querying a collection that does not have a DTD for >example. You may know that homes have an id, but you don't know >whether the id is an attribute or a element. Another case is a >relational->XML wrapper, it export relational attributes as >XML attributes, but might as well export them as elements. Isn't your complaint really that there is no standard mapping from a relational schema to a notional DTD/Schema? Let alone for round-tripping. A policy that said "1 field equals 1 element" would meet your requirements even in XML ; SML reduces the choices in one area, but not enough to make querying work automatically. Without such a mapping policy, you cannot assume anything about what is returned by a query. If the database uses case-sensitive names, which case is returned for the generic identifier? If the data is stored as a date, what date format is returned? If a text field is used, can that text field contain markup? So it would be a standard mapping policy that would fix the problem, in any markup language. Rick Jelliffe xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@i... Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ and on CD-ROM/ISBN 981-02-3594-1 To unsubscribe, mailto:majordomo@i... the following message; unsubscribe xml-dev To subscribe to the digests, mailto:majordomo@i... the following message; subscribe xml-dev-digest List coordinator, Henry Rzepa (mailto:rzepa@i...)
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