[Mulgara-general] SPARQL Query question.

[Campbell Allen]

Hi,

I am testing out Mulgara for use as a RDF Store / SPARQL end point.  As such
I am trying to execute a SPARQL query (below) with an OPTIONAL clause in it
but receive this error (query provided below).   This query works with other
SPARQL endpoints, so I am hoping you can shed some light on this.

Kindly,
Campbell.
-- 
Campbell Allen, M.Phil Candidate
ITEE & Centre for Marine Studies
University of Queensland
St Lucia, Brisbane 4072

----------------------------
ERROR:

 WARN [main] (Query.java:175) - Failed to find $lon_end in [$actorname,
$lat, $value, $observation, $characteristic_type, $enddate, $unit, $depth,
$locname, $lon, $target, $characteristic, $target_type, $measurement,
$begindate, $instance, $unitsymbol, $datetime, $context, $location, $actor]
java.lang.IllegalArgumentException: Failed to constrain all variables:
$lon_end not constrained in WHERE or GIVEN clauses    at
org.mulgara.query.Query.<init>(Query.java:176)    at
org.mulgara.sparql.SparqlInterpreter.buildSelectQuery(SparqlInterpreter.java
:258)    at 
org.mulgara.sparql.SparqlInterpreter.parseQuery(SparqlInterpreter.java:214)
at MulgaraTest.queryStore(MulgaraTest.java:259)    at
MulgaraTest.main(MulgaraTest.java:458) java.lang.NullPointerException    at
MulgaraTest.queryStore(MulgaraTest.java:278)    at
MulgaraTest.main(MulgaraTest.java:458) WARN [main] (Query.java:175) - Failed
to find $end_lon in [$actorname, $lat, $value, $observation,
$characteristic_type, $enddate, $unit, $locname, $lon, $target,
$characteristic, $target_type, $measurement, $begindate, $instance,
$unitsymbol, $datetime, $context, $location, $actor]
java.lang.IllegalArgumentException: Failed to constrain all variables:
$end_lon not constrained in WHERE or GIVEN clauses    at
org.mulgara.query.Query.<init>(Query.java:176)    at
org.mulgara.sparql.SparqlInterpreter.buildSelectQuery(SparqlInterpreter.java
:258)    at 
org.mulgara.sparql.SparqlInterpreter.parseQuery(SparqlInterpreter.java:214)
at MulgaraTest.queryStore(MulgaraTest.java:259)    at
MulgaraTest.main(MulgaraTest.java:458)

------------------------------------------------
QUERY:

 PREFIX event: <http://maenad.itee.uq.edu.au/metadata/Event#> PREFIX
spatial: <http://maenad.itee.uq.edu.au/metadata/Spatial#> PREFIX context:
<http://maenad.itee.uq.edu.au/metadata/Context#> PREFIX temporal:
<http://maenad.itee.uq.edu.au/metadata/Temporal#> PREFIX physical:
<http://maenad.itee.uq.edu.au/metadata/Physical#> PREFIX actor:
<http://maenad.itee.uq.edu.au/metadata/Actor#> PREFIX abstract:
<http://maenad.itee.uq.edu.au/metadata/Abstract#> PREFIX xsd:
<http://www.w3.org/2001/XMLSchema#> PREFIX rdf:
<http://www.w3.org/1999/02/22-rdf-syntax-ns#> PREFIX rdfs:
<http://www.w3.org/2000/01/rdf-schema#> SELECT DISTINCT * WHERE {  ?datetime
temporal:has_datetime ?begindate .  FILTER (?begindate >=
"2000-01-01T00:00:00"^^xsd:dateTime) .  OPTIONAL { ?datetime
temporal:has_end_datetime ?enddate .  FILTER (?enddate <=
"2009-05-31T23:59:59"^^xsd:dateTime) . } .  ?context context:has_datetime
?datetime .  ?location spatial:has_longitude ?lon .  ?location
spatial:has_latitude ?lat .  OPTIONAL { ?location spatial:has_end_longitude
?lon_end .                   ?location spatial:has_end_latitude ?lat_end . }
.  ?context context:has_location ?location .  ?measurement event:has_unit
?unit .  ?measurement event:has_value ?value .  ?measurement
event:has_characteristic ?characteristic_type .  ?instance event:has_actor
?actor .  ?instance event:of_target ?target_type .  ?instance
event:has_context ?context .  ?instance event:has_measurement ?measurement .
?instance rdf:type ?observation .  ?observation rdfs:subClassOf
event:Observation . }
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mulgara.org/pipermail/mulgara-general/attachments/20090730/3122f6d9/attachment.htm>