[Bigdata-developers] TupleQuery vs. ParsedQuery

[Adrian B. <Adr...@ma...>]

Hello everyone,

I'm writign on behalf of a Wikidata Research Project
<https://meta.wikimedia.org/wiki/Research:Understanding_Wikidata_Queries>
into SPARQL-Queries. We are writing a java application to parse
SPARQL-Queries from the query.wikidata.org-logs and analyse them for
different features. At the moment we are parsing the queries with
org.openrdf.query.parser.QueryParserUtil into
org.openrdf.query.parser.ParsedQuery-Objects. Unfortunatly we cannot
parse queries like this one:

SELECT DISTINCT ?item
WHERE
{ ?tree0 wdt:P31 ?item . BIND (wd:Q146 AS ?tree0) }

because of: "BIND clause alias '{}' was previously used".

If we parse them as org.openrdf.query.TupleQuery-Objects using
org.openrdf.repository.RepositoryConnection.prepareTupleQuery they are
parsed just fine.

Unfortunatly, the TupleQuery-Objects do not support the
analysis-Features of ParsedQuery.

All of which leads to 2-3 questions:

1. Why is this kind of query accepted by one parser but not the other?
2. Is it possible to obtain a ParsedQuery-Object from a TupleQuery-Object?
(3. Is this the right mailing list to post these questions to?)

Greetings,

Adrian Bielefeldt