Hi!
On 1/14/17 9:23 AM, Adrian Bielefeldt wrote:
I was wondering if anybody could help me understand
why (and how) this
query:
SELECT DISTINCT ?item
WHERE
{ ?tree0 wdt:P31 ?item . BIND (wd:Q146 AS ?tree0) }
is being accepted by
query.wikidata.org.
Probably Blazegraph engine considers it analogous with the query having
the bind in front, or maybe optimization reorders it.
At the moment we are parsing them using OpenRDF, which
fails (as far
as I can see understandably) at parsing this query.
Well, the standard does say you can not use a variable in BIND that was
previously used, and I guess OpenRDF parser chooses to be more strict
than Blazegraph.
--
Stas Malyshev
smalyshev(a)wikimedia.org