[redland-dev] NULL string for librdf_query_results_to_string() on empty results?

Fri Jan 12 04:07:53 UTC 2007

I am trying to implement a SPARQL endpoint webservice to a Redland
database.  When I do a query that finds no results, the stringification
of the query results is NULL (undef in Perl).  My understanding of the
required XML output(http://www.w3.org/TR/rdf-sparql-XMLres/) for the
results of an empty (but not malformed or otherwise errant) query should
list the <head> section of selected variables and an empty <results>
element.

My simple SELECT * WHERE { ?s ?p ?o } query isn't getting any errors
when I put some data in the database, but when there is no data (or when
the WHERE clause doesn't match any data I get this bogus string, with no
error or warning from Redland.

I am using Redland v 1.0.4 with Rasqal 0.9.13.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.usefulinc.com/pipermail/redland-dev/attachments/20070111/ddca9a25/attachment.htm