[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Koha-zebra] Incomplete CQL Support in Net-Z3950-ZOOM
From: |
Mike Taylor |
Subject: |
Re: [Koha-zebra] Incomplete CQL Support in Net-Z3950-ZOOM |
Date: |
Wed, 21 Dec 2005 00:24:54 GMT |
> Date: Fri, 16 Dec 2005 15:05:01 +0100
> From: Thomas D <address@hidden>
>
> I have found some issues with Net-Z3950-ZOOM for the use of CQL, as
> the underlying query syntax for Koha in 3.0 and beyond.
Hi, Thomas, thanks for your comments.
> "scan()"
> ...
> "All of this is done by using a single term from the PQF query as
> the scan() argument. (At present, only PQF is supported, although
> there is no reason in principle why CQL and other query syntaxes
> should not be supported in future)."
>
> Scan has many potential very important applications for guiding user
> queries based on the contents of the record instead of requiring the
> user to do more guessing for what query terms may be actually
> present in the index for the database of records.
I agree. I have added support for CQL scanning to ZOOM-Perl (and
therefore to the underlying ZOOM-C). It's tested, working and checked
into CVS, and should be released some time in the next few days. So
now you can say:
($ss, $n) = $conn->scan(new ZOOM::Query::CQL('dc.title=dinosaur');
(You may applaud.)
> "sortby()"
> ...
> "It ought to be possible to sort by CQL query, too, but at present
> limitations in the underlying ZOOM-C library make this impossible."
Yeah, I was talking complete cheese there, sorry. Sort specification
in ZOOM-C (and therefore ZOOM-Perl) are in a completely separate
language that has nothing to do with either CQL or RPN. The comment
in the documentation is meaningless. (It'll be fixed in v1.01.)
> Is the lack of sortby() support for CQL merely a significant
> inconvenience rather than something that would absolutely prevent
> the use of CQL when sorting records by some element is needed?
I see the the documentation is unclear as well as incorrect :-)
There is no problem at all with using CQL to search and then sorting
the result. What I was lamenting was that CQL can't be used to
specify the sort criteria themselves. Well, duh! Neither can FORTRAN
or Serbo-Croat. That's because none of them are sort-specification
languages.
So there is no problem here.
In the medium term, plans are afoot to extend the CQL specification
with syntax for sorting like this:
dc.author=Adams sortby dc.date dc.title
Once this is agreed, ZOOM-C will no doubt implement it, and therefore
so will ZOOM-Perl. "Great things are afoot."
> It would be a shame if these issues mitigated against using CQL, the
> otherwise best tool for the job.
Agreed.
_/|_ ___________________________________________________________________
/o ) \/ Mike Taylor <address@hidden> http://www.miketaylor.org.uk
)_v__/\ "Connery doesn't act anymore, he just plays Sean Connery" --
Richard Sherbaniuk.
[Koha-zebra] Re: [Koha-devel] Perl-ZOOM is a GO!, Nathan Gray, 2005/12/20
[Koha-zebra] Zebra and non-filing characters, Joshua Ferraro, 2005/12/22