Unable to see Max in SPARQL Query - sparql

Im trying to query a knowledge graph and im trying print the max occurrence of ?n in the result and i have tried running following query but it just doesn't prints anything
here is my SPARQL Query
PREFIX : <http://www.tafsirtabari.com/ontology#>
PREFIX RDF:<http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
select
?n
(MAX( xsd:int(?countOfSharedLikedItems)) as ?max)
(COUNT(?n) as ?countOfSharedLikedItems)
where {
?h :hasTheme :lugha .
?h RDF:type :Hadith .
?h :hasHadithNo ?o.
?p :isPartOfHadith ?h.
{
?p :hasNarratorSegment ?nc.
?nc :refersTo+/:hasName ?n.
}
Union
{
?p :hasRootNarratorSegment ?rnc.
?rnc :refersTo+/:hasName ?n.
}
}
i have also tried following by using group by ?n
PREFIX : <http://www.tafsirtabari.com/ontology#>
PREFIX RDF:<http://www.w3.org/1999/02/22-rdf-syntax-ns#>
select
(MAX(?countOfSharedLikedItems) as ?max)
(COUNT(?n) as ?countOfSharedLikedItems)
where {
?h :hasTheme :lugha .
?h RDF:type :Hadith .
?h :hasHadithNo ?o.
?p :isPartOfHadith ?h.
{
?p :hasNarratorSegment ?nc.
?nc :refersTo+/:hasName ?n.
}
Union
{
?p :hasRootNarratorSegment ?rnc.
?rnc :refersTo+/:hasName ?n.
}
} group by ?n

You can try this
PREFIX : <http://www.tafsirtabari.com/ontology#>
select (COUNT(?o ) AS ?triples) where {
?k :heardFrom ?o
}
6. Which RAWI narrated most hadiths about TOPIC_A
PREFIX hash: <http://www.tafsirtabari.com/ontology#>
PREFIX W3:<http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX : <http://www.tafsirtabari.com/ontology#>
SELECT ?total WHERE{
select DISTINCT ?n (COUNT(?n) as ?total) where {
?commentary hash:mentions hash:اهل_المعرفه .
?segment hash:containsCommentary ?commentary.
?segment ?Fr ?h .
?h W3:type hash:Hadith.
?p :isPartOfHadith ?h.
{
?p :hasNarratorSegment ?nc.
?nc :refersTo+/:hasName ?n.
}
Union
{
?p :hasRootNarratorSegment ?rnc.
?rnc :refersTo+/:hasName ?n.
}
}GROUP BY ?n
}ORDER BY DESC(?total)
LIMIT 1

Related

Is there a WITH clause in SPARQL?

Is there any analog of view creation or WITH clause from SQL in SPARQL?
I want to:
Select some data from table;
Select data which is not in the first selection (by subject) from the same table.
This seems to work without "WITH" but i do two similar SELECT query:
SELECT *
FROM NAMED <http://...>
{
{
SELECT DISTINCT ?s ?p ?o
WHERE {
BIND (<http://www.w3.org/2004/02/skos/core#prefLabel> AS ?p)
{ ?s <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2004/02/skos/core#Concept> . }
FILTER(LANGMATCHES(LANG(?o), "ru"))
}
ORDER BY ?o
}
UNION
{
SELECT DISTINCT ?s ?p ?o
WHERE {
BIND (<http://www.w3.org/2004/02/skos/core#prefLabel> AS ?p)
{ ?s <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2004/02/skos/core#Concept> . }
FILTER(LANGMATCHES(LANG(?o), "en"))
MINUS {
SELECT DISTINCT ?s
WHERE {
BIND (<http://www.w3.org/2004/02/skos/core#prefLabel> AS ?p)
{ ?s <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2004/02/skos/core#Concept> . }
FILTER(LANGMATCHES(LANG(?o), "ru"))
}
}
}
ORDER BY ?o
}
}

sparql count not existing properties as zero

Here is my query:
PREFIX : <http://example.org/ns#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
SELECT ?id ?name (count(?s) as ?count)
WHERE {
?t a :Tag ;
:hasId ?id ;
:hasName ?name
OPTIONAL { ?s :hasTag ?t ;
rdf:type ?type }
FILTER (?type in (:Client, :Project, :Staff))
} GROUP BY ?id ?name
Tags with no objects are not included in the result. How can I get them also without using union?
Performance is also important
The goal is to gather information about tags (id, name) and number of objects they assign to (if no such objects count must be 0). Tag data sample:
:tag912 :hasId "912"^^xsd:integer
:tag912 :hasName "Phones"
This tag is assigned to 6 objects.
This query works for me:
PREFIX : <http://example.org/ns#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
SELECT ?id ?name ?count
WHERE {
{
SELECT ?id ?name (count(?s) as ?count)
WHERE {
?t a :Tag ;
:hasId ?id ;
:hasName ?name .
?s :hasTag ?t ;
rdf:type ?type
FILTER (?type in (:Client, :Project, :Staff))
} GROUP BY ?id ?name
} UNION {
SELECT ?id ?name (0 as ?count)
WHERE {
?t a :Tag ;
:hasId ?id ;
:hasName ?name
FILTER not exists { ?s :hasTag ?t }
}
}
}
How can I use bindings here? Will it improve performance?
Thank you
Why not use UNION?
Aside from that, your query is focused on ?t tags and their ?id and ?name — so it's not surprising that results don't include ?s objects which lack ?t and hence lack any ?id and ?name…
I think this may get you going in the right direction —
PREFIX : <http://example.org/ns#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
SELECT ?id
?name
(count(?s) as ?count)
WHERE
{ ?s rdf:type ?type
FILTER ( ?type IN ( :Client, :Project, :Staff ) ) .
OPTIONAL { ?s :hasTag ?t .
?t rdf:type :Tag ;
:hasId ?id ;
:hasName ?name }
}
GROUP BY ?id ?name
You can check if ?s is bound in your filter:
PREFIX : <http://example.org/ns#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
SELECT ?id ?name (COUNT(?s) as ?count)
WHERE {
?t a :Tag ;
:hasId ?id ;
:hasName ?name .
OPTIONAL {
?s :hasTag ?t ;
rdf:type ?type .
}
FILTER (!BOUND(?s) || ?type in (:Client, :Project, :Staff))
} GROUP BY ?id ?name
I don't know if this is faster than a union (or a bunch of unions), however.

Sparql about dbpedia:World_Wide_Web

I'm new to the semantic web and I'm trying to figure out how to write a SPARQL query to extract from dbpedia everything about a particular subject. Not just it's proprieties, but also everything related to it.
I'm not even sure how to start such a query.
I would like to get all triples about the World Wide Web.
PREFIX dbpedia: <http://dbpedia.org/resource/>
SELECT DISTINCT ?s ?p ?o
WHERE {
?s ?p ?o .
?s ?p dbpedia:World_Wide_Web
# FILTER( lang(?s) = "en" ) -- doesn't work with filter
}Limit 100
This only returns some triples with a owl:sameAs predicate
Can you help me?
You can get all the triples that have dbpedia:World_Wide_Web as their subject or object with a query like this (this only gives 1000, of course). For any objects that are literals, we can restrict their language value:
select ?s ?p ?o where {
values ?web { dbpedia:World_Wide_Web }
{ ?web ?p ?o bind( ?web as ?s ) } union
{ ?s ?p ?web bind( ?web as ?o ) }
# for literal objects, take only English ones
filter( !isLiteral(?o) || langMatches(lang(?o),'en') )
}
limit 1000
SPARQL results
This includes results like the following, which seems to align with what you mentioned in the comments:
http://dbpedia.org/resource/World_Wide_Web http://dbpedia.org/property/company http://dbpedia.org/resource/CERN
http://dbpedia.org/resource/World_Wide_Web http://dbpedia.org/property/inventor http://dbpedia.org/resource/Tim_Berners-Lee
That will produce a lot of results, so you might want to restrict the properties that you can use. You should be able to do the following, but on the current DBpedia endpoint, it causes an error.
select ?s ?p ?o where {
values ?web { dbpedia:World_Wide_Web }
values ?p { rdf:type dbpedia-owl:abstract }
{ ?web ?p ?o bind( ?web as ?s ) } union
{ ?s ?p ?web bind( ?web as ?o ) }
}
limit 1000
Virtuoso 37000 Error SP031: SPARQL compiler: Internal error: sparp_gp_attach_filter_cbk(): attempt to attach a filter with used variable
SPARQL query:
define sql:big-data-const 0
#output-format:text/html
define sql:signal-void-variables 1 define input:default-graph-uri <http://dbpedia.org> select ?s ?p ?o where {
values ?web { dbpedia:World_Wide_Web }
values ?p { rdf:type dbpedia-owl:abstract }
{ ?web ?p ?o bind( ?web as ?s ) } union
{ ?s ?p ?web bind( ?web as ?o ) }
}
limit 1000
Instead, as a workaround, you can do this:
select ?s ?p ?o where {
values ?web { dbpedia:World_Wide_Web }
{ ?web ?p ?o bind( ?web as ?s ) }
union
{ ?s ?p ?web bind( ?web as ?o ) }
filter( ?p in (rdf:type, dbpedia-owl:abstract )) ###
}
limit 1000
SPARQL results

UNION operator in SPARQL updates

I have two SPARQL updates.First one:
INSERT
{ GRAPH <[http://example/bookStore2]> { ?book ?p ?v } }
WHERE
{ GRAPH <[http://example/bookStore]>
{ ?book dc:date ?date .
FILTER ( ?date > "1970-01-01T00:00:00-02:00"^^xsd:dateTime )
?book ?p ?v
} }
Second:
INSERT
{ GRAPH <[http://example/bookStore2]> { ?book ?p ?v } }
WHERE
{ GRAPH <[http://example/bookStore3]>
{ ?book dc:date ?date .
FILTER ( ?date > "1980-01-01T00:00:00-02:00"^^xsd:dateTime )
?book ?p ?v
} }
Can i combine them with the UNION operator? And if yes, is it an equivalent result? Is it possible to use UNION in SPARQL updates such as in "Select"?
AndyS's answer is correct; you can combine them, and the description of UNION is found in section 7 Matching Alternatives of the SPARQL specification. The combined query would be:
INSERT {
GRAPH <[http://example/bookStore2]> { ?book ?p ?v }
}
WHERE{
{
GRAPH <[http://example/bookStore]> {
?book dc:date ?date .
FILTER ( ?date > "1970-01-01T00:00:00-02:00"^^xsd:dateTime )
?book ?p ?v
}
}
UNION
{
GRAPH <[http://example/bookStore3]> {
?book dc:date ?date .
FILTER ( ?date > "1980-01-01T00:00:00-02:00"^^xsd:dateTime )
?book ?p ?v
}
}
}
In this particular case where the patterns are so similar, you could also just abstract out the differing parts with VALUES:
INSERT {
GRAPH <[http://example/bookStore2]> { ?book ?p ?v }
}
WHERE{
values (?graph ?startDate) {
(<[http://example/bookStore]> "1970-01-01T00:00:00-02:00"^^xsd:dateTime)
(<[http://example/bookStore3]> "1980-01-01T00:00:00-02:00"^^xsd:dateTime)
}
GRAPH ?graph {
?book dc:date ?date .
FILTER ( ?date > ?startDate )
?book ?p ?v
}
}
The WHERE clause is the same as SPARQL Query - you can use UNION.

Union of two selects in a SPARQL query

I'd like to do something like
{
SELECT ?page, "A" AS ?type WHERE
{
?s rdfs:label "Microsoft"#en;
foaf:page ?page
}
}
UNION
{
SELECT ?page, "B" AS ?type WHERE
{
?s rdfs:label "Apple"#en;
foaf:page ?page
}
}
But this gives a syntax error. How can I union two select queries in SPARQL?
You can union them like this:
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
SELECT * WHERE
{
{
SELECT ?page ("A" AS ?type) WHERE
{
?s rdfs:label "Microsoft"#en;
foaf:page ?page
}
}
UNION
{
SELECT ?page ("B" AS ?type) WHERE
{
?s rdfs:label "Apple"#en;
foaf:page ?page
}
}
}
(check with the SPARQL validator)
However I don't think you need sub queries at all for this case. For example:
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
SELECT ?page ?type WHERE
{
?s foaf:page ?page .
{ ?s rdfs:label "Microsoft"#en . BIND ("A" as ?type) }
UNION
{ ?s rdfs:label "Apple"#en . BIND ("B" as ?type) }
}
Based on #user205512's answer, here's one that works on Virtuoso:
SELECT * {
?s foaf:page ?page .
{
SELECT ?page ("A" AS ?type) {
?s rdfs:label "Microsoft"#en;
foaf:page ?page
}
} UNION {
SELECT ?page ("B" AS ?type) {
?s rdfs:label "Apple"#en;
foaf:page ?page
}
}
}
The trick was just do add an additional ?s foaf:page ?page triple outside of the UNION. This is obviously redundant, but it seems to avoid the Virtuoso bug, which is apparently caused when you have a “naked” UNION with subqueries.