- From: Julian Reschke <julian.reschke@gmx.de>
- Date: Thu, 14 Jun 2001 12:33:30 +0200
- To: "Babich, Alan" <ABabich@filenet.com>, <w3c-dist-auth@w3.org>
> From: w3c-dist-auth-request@w3.org > [mailto:w3c-dist-auth-request@w3.org]On Behalf Of Babich, Alan > Sent: Wednesday, June 13, 2001 9:39 PM > To: 'Julian Reschke'; w3c-dist-auth@w3.org > Subject: RE: Moving DASL to Experimental > > (stuff deleted) > > --- > > I don't think putting data type information into the query on > PROPERTIES is > all that useful. After all, the server knows or should know about the data > types of the properties it has stored. I think that putting data type > information on the LITERALS in the query would be much more useful. (For > example, is "<literal>123</literal>" the integer 123 or the string "123", > i.e., what did the client intend?) If data types are put on the literals, > then even if the client doesn't know the data type of the property on the > server, at least the server will know how to coerce the literal to the > correct data type in cases where that is possible. (Some RDBMS's do, in > fact, perform such coercions, e.g. Oracle.) The client can force the user > choose what data type to enter for literals if it wants to, so the client > can know what the user intends for the data type, even without > query schema > discovery. > > My suggestion of putting data types on the literals via attributes in the > literal XML element was rejected, at least partly because people > expected an > XML committee to invent data types in XML itself. We, DASL, didn't want to > do anything at variance with what that committee would come up with. > Furthermore, we didn't think it was feasible to track what they were doing > or to tie our schedule to theirs. A significant amount of time has elapsed > since then, and I haven't tracked the XML data types effort. So, I don't > know what the status of data types in XML is. If XML now has data > types for > literals, I would use them. If it doesn't, then, you have the same problem > we did. I think that putting datatype information into literals makes sense, and with XML Schema (Part 2 I think) . I recently proposed a method for specifiying data types upon PROPPATCH [1], a similar method could be introduced for basicsearch as well, for instance: <literal xsi:type="xs:dateTime">2001-06-14T13:31:00Z</literal> As for querying structured properties, I think DASL should rely on the technologies that have been defined for this (XPath). One could even conceive writing the full query as XSLT :-). [1] <http://lists.w3.org/Archives/Public/w3c-dist-auth/2001AprJun/0247.html>
Received on Thursday, 14 June 2001 06:33:57 UTC