W3C home > Mailing lists > Public > xmlschema-dev@w3.org > June 2004

RE: keyref with empty sets

From: Zafar Abbas <zafara@microsoft.com>
Date: Tue, 1 Jun 2004 12:01:59 -0700
Message-ID: <563BD3496D37BB4B9F4E8F896A58F2B3CFC6C2@RED-MSG-50.redmond.corp.microsoft.com>
To: "Henry S. Thompson" <ht@inf.ed.ac.uk>, "Nigel Hardy" <nwh@aber.ac.uk>
Cc: <xmlschema-dev@w3.org>

>Basically, the REC (correctly, in my view) imposes _no_
>requirements on keys if there are no hits for a keyref

From my reading of the clause below, it does seem that the content
selected by a key _must_ exist in the content, and if someone wanted to
have null keys, one would use xs:unique.

structures spec section 3.11.1:
{key) the Identity-constraint definition asserts uniqueness as for
unique. key further asserts that all selected content actually has such
tuples.



-Zafar
Received on Tuesday, 1 June 2004 15:03:06 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 11 January 2011 00:14:44 GMT