Exact match of variable string in SPARQL Wikidata Query Service at https://query.wikidata.org does not give the the results I expected.
I was expecting I could do:
SELECT * {
hint:Query hint:optimizer "None" .
{ SELECT DISTINCT (xsd:string(?author_name_) AS ?author_name) { wd:Q5565155 skos:altLabel ?author_name_ . } }
?work wdt:P2093 ?author_name .
}
But I get no returned results from the Wikidata Query Service:
However, if I use the "=" comparison, I can match the strings:
SELECT * {
hint:Query hint:optimizer "None" .
{ SELECT DISTINCT (xsd:string(?author_name_) AS ?author_name) { wd:Q5565155 skos:altLabel ?author_name_ . } }
?work wdt:P50 wd:Q5565155 .
?work wdt:P2093 ?author_name__ .
FILTER (?author_name = ?author_name__)
}
With the current data in Wikidata, I get five rows returned in this query.
Another way to get this data is by using a BIND:
SELECT * {
BIND("Knudsen GM" AS ?author_name)
?work wdt:P2093 ?author_name .
}
I suppose there might be something wrong with the casting as this does not return anything:
SELECT * {
BIND(xsd:string("Knudsen GM") AS ?author_name)
?work wdt:P2093 ?author_name .
}
Combinations with xsd:string changed to STR or no conversion at all in the original query do neither yield result rows.
Related
I am trying to replace the value of code_type when it is empty and belongs to ifcowl:IfcSite with "INF" via this attempt. I don't know if this is possible.
First, I get the code_type values I need and I use the "values" block to replace the values
However, some values are empty and among these empty values, I have to replace the empty value by "INF" but only for ifcowl = IfcSite
Here is my attempt and thank you in advance for your help :
select ?code_type ?gid ?VALUE1 ?TEST
PREFIX ifcowl: <http://www.buildingsmart-tech.org/ifcOWL/IFC2X3_TC1#>
PREFIX express: <https://w3id.org/express#>
PREFIX blabla: <https://www.blabla.fr/>
PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
PREFIX iso23386: <https://www.iso.org/standard/iso23386#>
{
?o a ?class .
GRAPH blabla:optimized {
OPTIONAL {?o blabla:SEQ_GUID ?gid}
OPTIONAL {?o blabla:code_type ?code_type}
OPTIONAL {?o blabla:VALUE1 ?VALUE1}
FILTER (?code_type IN
(""^^xsd:string, "ATE_PCO"^^xsd:string, "ATE_SCA"^^xsd:string, "ATE_TNT"^^xsd:string))
}
optional {
values (?code_type ?TEST) {
("" "ZONE" && ?class = ifcowl:IfcSite)
}
}
optional {
values (?code_type ?TYPE) {
("ATE_PCO" "PCO")
("ATE_SCA" "CABLE")
("ATE_TNT" "TNT")
}
values (?code_type ?NOMOS) {
("ATE_PCO" "ABC")
("ATE_SCA" "BDC")
("ATE_TNT" "EDG")
}
}
}
I am trying to have SPARQL return 'false' if a set of triples exist in an RDF database. I'm able to return 'true' with an ASK query.
ASK WHERE { ?subjID rdf:type pref:Person. }
As described here, I tried adding NOT EXISTS { } inside of the WHERE, but this results in an error.
ASK WHERE { NOT EXISTS { ?subjID rdf:type pref:Person. } }
The documentation that I linked doesn't describe this but you must put FILTER in front of NOT EXISTS.
ASK WHERE { FILTER NOT EXISTS { ?subjID rdf:type pref:Person. } }
Can anyone help me in sparql. I'm working on ontology based project. I've a structure in protege-owl like
City-hasWeatherConditions-(multiple value i.e temp,dewpoint)
I want to get values against each attribute.
Query:
PREFIX pro: <http://www.semanticweb.org/computer/ontologies/2019/0/fyp.owl#>
select ?indi ?val
where
{
{
select ?indi
where
{
pro:Lahore
<http://www.semanticweb.org/computer/ontologies/2019/0/fyp.owl#hasWeatherCondition>
?indi
}
}
{
select ?val
where
{
<http://www.semanticweb.org/computer/ontologies/2019/0/fyp.owl#DewPoint>
<http://www.semanticweb.org/computer/ontologies/2019/0/fyp.owl#hasDewPoint>
?val
}
}
}
Figure1: Note -- 5.21 is DewPoint value which is repeated in temp.
Figure2:
Is it possible to count the occurrences of triples in multiple named graphs and return the results as rows in a table? Such as:
?g ?count ?sequence_count
-------- ------- ---------------
graph1 54 54
graph2 120 80
Here is the query that I tried.
SELECT ?g ?count ?sequence_count
FROM NAMED <graph1>
FROM NAMED <graph2>
WHERE {
{
select (COUNT(?identifier) as ?count) (COUNT(?sequence) as ?sequence_count)
WHERE { GRAPH ?g {
?identifier a <http://www.w3.org/2000/01/rdf-schema#Resource> .
OPTIONAL { ?identifier <urn:sequence> ?sequence }
} }
}
}
But the results were:
?g ?count ?sequence_count
-------- ------- ---------------
174 134
I'm trying to avoid having to write out:
select ?count_graph1 ?sequence_count_graph1 ?count_graph2 ...
as there could be hundreds of graphs to query.
First, the query is really close. Just move the SELECT inside of the graph statement - basically stating 'for each graph, find these aggregate values'. Second, if any of the ?identifier matches have multiple values, the count for ?identifier will have duplicates, so DISTINCT results are necessary. Try the following:
SELECT *
FROM NAMED <graph1>
FROM NAMED <graph2>
WHERE {
GRAPH ?g {
SELECT (COUNT(DISTINCT ?identifier) as ?count) (COUNT(?sequence) as ?sequence_count)
WHERE {
?identifier a <http://www.w3.org/2000/01/rdf-schema#Resource> .
OPTIONAL { ?identifier <urn:sequence> ?sequence }
}
}
}
How do I change the query formula based on whether or not a variable is bound?
I am invoking the magic property like this:
WHERE {
VALUES (?subj) {
([my bound positional parameter value goes here...])
}
?subj :myMagicProperty ?result .
}
Inside the magic property, I do a union:
?result a :Rule .
{
?result :someProp ?subj .
}
UNION
{
FILTER NOT EXISTS {
?result :someProp ?anyValue .
}
}
In other words, get me all results where :someProp is this value or :someProp is not defined.
Here is the tricky part. If ?subj is unbound (i.e., I set it as UNDEF in the VALUES block), the above query goes wild and returns everything.
Instead, I want to check if ?subjis unbound. If ?subj is unbound, :myMagicProperty should only return the following results:
FILTER NOT EXISTS {
?result ?someProp ?anyValue .
}
I have experimented with using FILTER and the BOUND function, but I can't figure out how to get the correct behavior. How can I drop one of UNION clauses from my query when ?subj is not bound?
Updates
Revised the first query to add the VALUES block.
Added missing ?result a :Rule . statement.
Corrected ?someProp to :someProp.
First I'd like to confirm what your intent is. I'd like to do that by asking you to respond to the following query that you can run in TopBraid Composer.
SELECT *
WHERE { GRAPH <http://topbraid.org/examples/kennedys> {
VALUES (?property) {(kennedys:firstName) (kennedys:lastName) (UNDEF)}
{
FILTER(BOUND(?property) )
?s ?property ?result .
}
UNION
{
FILTER(!BOUND(?property))
BIND("not sure what you want to do in this case" AS ?result)
}
}
}
The difference in the code above to your code is that I am setting values of your ?someProp in the VALUES statement, whereas you are setting ?subj.
The UNIONed subgraphs are using BOUND and !BOUND as guards.
Before going further with help I'd like to hear from you with a clearer explanation of the query you are wanting to build. Then I can show you the magic property that will be needed.
It's this piece of your initial post I need to understand more:
Here is the tricky part. If ?subj is unbound (i.e., I set it as UNDEF in the VALUES block), the above query goes wild and returns everything.
Instead, I want to check if ?subj is unbound. If ?subj is unbound, myMagicProperty should only return the following results:
FILTER NOT EXISTS {
?result ?someProp ?anyValue .
}*
With ?someProp undefined, as well as ?result and ?anyValue, what were you expecting to come back? Also this subgraph of yours has no assertions that will populate the graph and therefore will return nothing.
Ralph
The trick is, I need to do the UNION using a variable different than the one passed in as an argument. This way, the UNION operation does not cause the unbound parameter to be bound. After the UNION, I can use a FILTER to control the results based on the input parameter.
SELECT ?result
WHERE {
?result a :Rule .
{
SELECT ?rule ?value ?anyValueMatch
WHERE {
{
?rule :someProp ?value .
BIND (false AS ?anyValueMatch) .
}
UNION
{
FILTER NOT EXISTS {
?rule :someProp ?any .
} .
BIND (true AS ?anyValueMatch) .
} .
}
} .
FILTER ((bound(?subj) && (?value = ?subj)) || (?anyValueMatch = true)) .
}
Another way to do this is with COALESCE:
SELECT ?result
WHERE {
?result a :Rule .
OPTIONAL {
?result :someProp ?value .
}
FILTER (COALESCE(?value = ?subj, !bound(?value)))
}
...this avoids the sub-select and simply filters to include only the ?result matches where '?value = ?subj', and if that clause fails the !bound() clause ensures matches that do not have a :someProp property are also included.