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   Re: [xml-dev] XML Schema question on key, keyref constraints

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Bob's comments are all correct, but that doesn't mean you can't get
closer to what you appear to want from this schema.  Simply move both
key and keyref decls to the element decl for the <root> element, and
you should correctly detect the key error (two plateNumber='1').

To get this _really_ right, you would need chained keyrefs, i.e. make
<code> be a key for states, and plateNumber a key for vehicles as now,
add a 'regState' attribute to <car> and have a double or chained
keyref, first to <state> by @regState and then to <vehicle> by

The XML Schema WG has a candidate requirement to add chained keyrefs
to a future version.

  Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
                      Half-time member of W3C Team
     2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
	    Fax: (44) 131 650-4587, e-mail: ht@cogsci.ed.ac.uk
		     URL: http://www.ltg.ed.ac.uk/~ht/
 [mail really from me _always_ has this .sig -- mail without it is forged spam]


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