This page is a portal to various resources concerning the new CQL
query language, on this site and elsewhere.
Descriptions
If you're not familiar with CQL, the best place to start is
probably with the
CQL Tutorial.
The formal specification for CQL, including a BNF grammar, is
held on the Z39.50 Maintenance Agency's CQL page at
http://www.loc.gov/standards/sru/cql#bnf
(I've also taken a
local copy
of the Maintenance Agency's page, mostly so I can access it
when I'm not on-line.)
A presentation that I made to the IMS Query SIG in November
2004.
A proposal by Eliot, Rob, Sebastian and myself to allow CQL
applications to
profile more of the query language
- specifically relations and relation modifiers - so as to
allow a broad range of non-bibliographic applications yet to
be considered.
This was accepted into mainstream CQL at the meeting of
25th-26th September 2003.
A nice, simple
Bath Profile
for CQL, including a Bath Context Set.
I have written a free Java library of CQL utilities, including
as its centerpiece a compiler with a variety of back-ends.
It's called CQL-Java
and is available for download from this site.
Adam Dickmeiss
<adam@indexdata.dk>
has written a CQL-to-XCQL compiler library in C, using
Yacc/Bison. It is available as a part of the
YAZ toolkit
from version 2.0 (23rd February 2003) onwards.
Chick Markley
<chick@diglib.org>
announces the beta release of CQL-Ruby, a Ruby Gem that
implements a CQL parser. It is based on a translation of
CQL-Java, and serialises to SOLR rather than PQF.
The project site is
cql-ruby.rubyforge.org