Hi mark,

Srw.dd=* does not work either:

Identifier:	info:srw/diagnostic/1/27
Meaning:	
Details:	srw.dd
Message:	The index [srw.dd] did not include a searchable value

I suppose the only option left is to retrieve everything and filter the results on the client side.

Thanks for your quick reply.
Arash 


-----Original Message-----
From: Code for Libraries [mailto:[log in to unmask]] On Behalf Of Mike Taylor
Sent: 16 May 2012 10:43
To: [log in to unmask]
Subject: Re: [CODE4LIB] WorldCat SRU queries - elimination of records without a DDC no from the result set

There is no standard way in CQL to express "field X is not empty".
Depending on implementations, NOT srw.dd="" might work (but evidently
doesn't in this case).  Another possibility is srw.dd=*, but again
that may or may not work, and might be appallingly inefficient if it
does.  NOT srw.dd=null will definitely not work: "null" is not a
special word in CQL.

-- Mike.


On 16 May 2012 10:32, Arash.Joorabchi <[log in to unmask]> wrote:
>  Hi all,
>
> I am sending SRU queries to the WorldCat in the following form:
>
>
>                String host =
> "http://worldcat.org/webservices/catalog/search/";
>            String query = "sru?query=srw.kw=\"" + keyword + "\""
>                                + " AND srw.ln exact \"eng\""
>                                + " AND srw.mt all \"bks\""
>                                + " AND srw.nt=\"" + keyword + "\""
>                                + "&servicelevel=full"
>                                + "&maximumRecords=100"
>                              + "&sortKeys=relevance,,0"
>                                + "&wskey=[wskey]";
>
> And it is working fine, however I'd like to limit the results to those
> records that have a DDC number assigned to them, but I don't know what's
> the right way to specify this limit in the query.
>
>  NOT srw.dd=""
>  NOT srw.dd=null
>
> Neither of above work
>
>
> Thanks,
> Arash
>