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Proposed resolution for issue "null-ordering"

From: Julian Reschke <julian.reschke@gmx.de>
Date: Wed, 27 Nov 2002 20:39:54 +0100
To: <www-webdav-dasl@w3.org>
Message-ID: <JIEGINCHMLABHJBIGKBCMECDFOAA.julian.reschke@gmx.de>

Discussion:

ameliac@us.ibm.com 2002-02-20

In the WebDAV SEARCH spec (5.6, DAV:orderby), it says that nulls sort low,
to match SQL92. However, SQL92 and SQL99 both say "Whether a sort key value
that is null is considered greater or less than a non-null value is
implementation-defined, but all sort key values that are null shall either
be considered greater than all non-null values or be considered less than
all non-null values." (words taken from SQL99, 14.1 <declare cursor> General
Rule 2)c), in reference to null handling for the <order by clause>. ) I
would note that in 5.5.3 WebDAV SEARCH says nulls are less than all other
values in a comparison, so the DAV:orderby matches that statement, it just
gives an inaccurate reason.


Proposed resolution:

Replace

	"In the context of the DAV:orderby element, null values are considered to
collate before any actual (i.e., non null) value, including strings of zero
length (as in [SQL99])."

by

	"In the context of the DAV:orderby element, null values are considered to
collate before any actual (i.e., non null) value, including strings of zero
length."

Feedback appreciated,

Julian


[1]
<http://greenbytes.de/tech/webdav/draft-reschke-webdav-search-latest.html#rf
c.issue.null-ordering>
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<green/>bytes GmbH -- http://www.greenbytes.de -- tel:+492512807760
Received on Wednesday, 27 November 2002 14:40:28 GMT

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