[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Re: XML-QL Follow up
> For instance, I'd like to be able to issue something like: >select * from invoices where value(<total>) > 1000 >or >select * from musicians where name like 'Garcia' > Yes I think there's a need for this. Some observations: * You need to be clear whether you are aiming for a "boolean" style of predicate (every document either matches it or doesn't) or a "relevance ranking" approach. Your two examples illustrate the two types. SQL doesn't extend neatly to relevance ranking, which is far more effective than boolean queries for information retrieval applications. * If you want to do boolean queries, one approach is to define a mapping from XML to an object structure (the DOM?) and then use OQL. However, this would probably lead to very complex queries, with a lot of "there exists" and "for all" qualifiers to handle repeated child elements. If you want to reduce the complexity, you need to define a lot of "intuitive interpretations", e.g. "name like 'Garcia'" means "there exist one or more child elements N such that N.tag='name' and N.content.islike('Garcia')". The danger is that these can trip people over if their intuition is wrong - e.g. what does "name not like 'Garcia'" mean? * The real need is to make XML documents accessible to web search engines, where (a) the query language is already defined, and (b) the vast majority of queries are extremely simple. So it's not a new query language that's needed, but an intelligent interpretation of an existing query language in an XML context. Mike Kay 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/ To (un)subscribe, mailto:majordomo@i... the following message; (un)subscribe 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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