In my company's taxonomy, all concepts have a value for skos:prefLabel, and most have a bunch of values for a custom property -- let's call it ex:keyword -- whose values have the datatype rdf:langString. I want to find concepts where the value of skos:prefLabel does NOT exactly match ANY value of ex:keyword, when case and language are ignored.
It is fairly straightforward to write a query for concepts where the values DO match, like this:
SELECT *
WHERE {
?concept skos:prefLabel ?label ;
ex:keyword ?kw
FILTER (lcase(str(?label)) = lcase(str(?kw)))
}
Where I'm getting tripped up is in trying to negate this.
Using != in the FILTER would just return a bunch of cases where ?label and ?kw don't match, which is not what I'm after.
What I would like is to be able to use a FILTER NOT EXISTS, but that's invalid with an expression like (?a = ?b); it only works with something like {?a ?b ?c}.
I suspect that there is a proper way to express FILTER NOT EXISTS (?a = ?b) in SPARQL, but I don't know what it is. Can someone help?
The trick is to put the triple pattern for matching the keyword in the FILTER NOT EXISTS, like so:
SELECT *
WHERE {
?concept skos:prefLabel ?label .
FILTER NOT EXISTS { ?concept ex:keyword ?kw .
FILTER(lcase(str(?label)) = lcase(str(?kw)))
}
}
This query says "I want all concepts with a preflabel such that the concept has no keyword value that matches that prefLabel".
Related
I am trying to create two sets in SPARQL, and return the number of instances in ?set1 that do not exist in ?set2. I am trying to do this all in SPARQL, and I was not able to find a good resource on how to do this through FILTER, as well as using MINUS, but not having any luck.
SELECT COUNT(?set1)
WHERE {
?S ?P ?set1 .
?Q ?R ?set2 .
FILTER (member in ?set1 doesn't exist in ?set2
}
You could use FILTER NOT EXISTS:
SELECT (COUNT(?electronic) AS ?count)
WHERE {
?employee :usesElectronic ?electronic .
FILTER NOT EXISTS { ?company :ownsElectronic ?electronic . }
}
This counts the devices that
are used by any employee, and
are not owned by any company.
If you just need to know if such a case exists, and you are not interested in the count, you could use an ASK query instead, which returns TRUE or FALSE. For that, replace the whole SELECT line with ASK.
I'm interested in obtaining a list of available distinct hierarchies from statistics.gov.scot. The best-fit hierarchies, which I would like to list, are as follow:
http://statistics.gov.scot/def/hierarchy/best-fit#community-health-partnership
http://statistics.gov.scot/def/hierarchy/best-fit#council-area
http://statistics.gov.scot/def/hierarchy/best-fit#country
As available through API section of this sample geography.
Desired results
I would like for the desired results to return:
community-health-partnership
council-area
country
How can I construct query that would actually produce that, I can get a list of available all geographies via:
PREFIX sdmx: <http://purl.org/linked-data/sdmx/2009/dimension#>
SELECT DISTINCT ?framework
WHERE {
?a sdmx:refArea ?framework .
} LIMIT 10
I was trying something on the lines:
PREFIX fits: <http://statistics.gov.scot/def/hierarchy/best-fit#>
SELECT DISTINCT ?framework
WHERE {
?a fits ?framework .
} LIMIT 10
but naturally this syntax is not correct.
Starting on their SPARQL endpoint, you could do something like this --
DESCRIBE <http://statistics.gov.scot/def/hierarchy/best-fit#country>
Then, based on those results, you might try something like this, which results aren't exactly what you say you want, but might be better --
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
SELECT ?hierarchy
?label
WHERE
{ ?hierarchy rdfs:subPropertyOf <http://statistics.gov.scot/def/hierarchy/best-fit>
; rdfs:label ?label
}
I have some RDF data structured like this:
[ pref:ip_address "127.0.0.1" ;
pref:time "1459630844.482" ;
pref:url "https://google.com" ;
pref:user "johndoe"
] .
I need query that will return all results matching given IP, time frame (between from time and end time), url (even partial match) and user (also even partial match).
What I have now is simple query to get results based on single value, like this:
PREFIX pref: <http://something> SELECT DISTINCT * WHERE { ?u pref:user USER_VALUE . ?u ?p ?o . }
This returns all results with given user but only if given username is full match. Meaning it will return all results for johndoe if USER_VALUE is johndoe but not if it is john.
My knowledge of SPARQL is extremely limited and I appreciate any help. Thank you.
To do anything more than exact match, you need to use a FILTER and use operations like CONTAINS or REGEX.
Example:
{ ?u pref:user ?user .
?u ?p ?o .
FILTER( CONTAINS(?user, "john") )
}
There are a number of FILTER functions that may be useful including REGEX. See the spec for details.
How to display data's property label?
I working for dbpedia ontology,
I want to make a sparql query, below is my sample query. This result is mix up either datatype or object type, I want to datatype property name.
SELECT ?p ?pLabel ?domain ?range
{
?p rdfs:domain http://dbpedia.org/ontology/Person> .
}
ex: Following is data type example, but I cannot select only datatype, I want to display
type name.
"chat"
'chat'#fr with language tag "fr"
"xyz"^^<http://example.org/ns/userDatatype>
"abc"^^appNS:appDataType
'''The librarian said, "Perhaps you would enjoy 'War and Peace'."'''
1, which is the same as "1"^^xsd:integer
1.3, which is the same as "1.3"^^xsd:decimal
1.300, which is the same as "1.300"^^xsd:decimal
1.0e6, which is the same as "1.0e6"^^xsd:double
true, which is the same as "true"^^xsd:boolean
false, which is the same as "false"^^xsd:boolean
expect to result
Expect to result (only data type)
typename <- field name
string <- type name
int
boolean
int
double
boolean
How to make a sparql query?
Use function datatype() for that purpose. For example:
select distinct ?y datatype(?z)
{
?x a <http://dbpedia.org/class/yago/JeskolaBuzzUsers>.
?x ?y ?z.
filter (datatype(?z) != '')
}
PREFIX xsd: http://www.w3.org/2001/XMLSchema#
ASK WHERE
{
?item dm:amount ?amount .
FILTER ((datatype(?amount)) != xsd:integer)
}
The query engine still knew which ?amount values were integers and which were not,
because any unquoted series of digits with no period is treated as an integer.
Most of your work with datatypes in SPARQL will involve the use of functions that are
covered in more detail in the next section. Before we look at any of those, it’s a good
idea to know how representations of typed literals in your queries interact with different
kinds of literals in your dataset.
I want to select a triple using SPARQL. To do it, i'm using following query:
SELECT count (*)
WHERE {?s ?p ?o}
FILTER (?s=http://kjkhlsa.net && ?p=http://lkasdjlkjas.com && ?o=Test)
As answer i get fully wrong triple :( subject ist not equal to "http://kjkhlsa.net", predicate is not equal to "http://lkasdjlkjas.com" and object ist also not equal to "Test". Can someone explain me, what I'm doing wrong :(
edit1:
I have put the query into php file:
$inst_query = 'SELECT * { <http://kjkhlsa.net> <http://lkasdjlkjas.com> "Test"}';
echo $inst_query;
The answer from the echo was "SELECT * { "Test"}". Then i tried it with WHERE:
$inst_query = 'SELECT * WHERE { <http://kjkhlsa.net> <http://lkasdjlkjas.com> "Test"}';
echo $inst_query;
Here was the answer "SELECT * WHERE { "Test"}"...so, i'm missing the URIs, but this seems for me as php issue and not sparql problem.
edit2:
I've put the query into SPARQL Query editor and i get the response "no result"....but I'm sure, that i have this triple.
In its current form the question is not very clear (see my comment above).
Since you are essentially trying to get triples matching a pattern, it is more efficient to use a graph pattern instead of FILTER. Many SPARQL implementations first match candidate triples by graph patterns and only then apply the FILTER expression. In essence, with a ?s ?p ?o graph pattern, you're doing a linear scan over all your triples.
So, here's something that should work, using graph patterns instead of FILTER.
SELECT * { <http://kjkhlsa.net> <http://lkasdjlkjas.com> "Test" }
Notes: I didn't include COUNT(*) which is not standard SPARQL. <> around URIs. "" around literal.
Try to use this :
SELECT count (*) as ?count
WHERE {
?s ?p ?o
FILTER (?s=<http://kjkhlsa.net> && ?p=<http://lkasdjlkjas.com> && ?o=Test)
}
The following query uses the count function to count the number of distinct URI(s) returned to the ?s variable.
SELECT ?s (COUNT (DISTINCT ?s) as ?count)
WHERE {?s ?p ?o}
FILTER (?o="Test")