With the RDF query language SPARQL, I'm trying to find a way to do a boolean query (or any other query) for anything not in a Named Graph.
ASK { GRAPH null { ?s ?p ?o } }
Can't find really any documentation on searching specifically within an empty Named Graph. Also tried replacing null with <>, empty, and (nothing).
This query will look for triples in the default graph, then remove ones that are also in a named graph:
SELECT ?s ?p ?o {
?s ?p ?o
FILTER NOT EXISTS { GRAPH ?g { ?s ?p ?o } }
}
Related
I was wondering if anyone knew of a way to DELETE a triple based on 2 conditions:
Subject has a triple count of 1.
The only triple on the subject matches a predicate.
The obstacle I'm coming across with these 2 conditions is that in order to COUNT the number of statements on a subject, you must do GROUP BY ?s. Then you do not have the ability to filter any ?p value.
The most likely solution would be a subquery, but I am not sure how this would be structured.
I would write it like this:
DELETE { ?s ?p ?o }
WHERE {
{
SELECT ?s (COUNT(*) AS ?c) {
?s ?p ?o
}
GROUP BY ?s
}
FILTER (?c = 1)
?s ?p ?o
}
Does something like this work?
I assume that by "Subject has a triple count of 1" you mean that there is only one triple with this subject. For the case of 1, this is a bit easier since we can just check that "there does not exist another triple for the same subject."
DELETE { ?s ?p ?o }
WHERE {
?s ?p ?o
#-- the value of ?p is the predicate of interest.
#-- Alternatively, this could be a FILTER involving
#-- the variable ?p .
values ?p { <the-predicate> }
#-- There is no other triple with ?s as the subject
#-- that has a different subject or object. (I.e.,
#-- the only triple with ?s as a subject is with ?p
#-- and ?o .
filter not exists {
?s ?pp ?oo
filter (?pp != ?p || ?oo != ?o)
}
}
I have a large skos taxonomy that has some incorrect notation properties. Most of the properties are xsd:string but some appear with a "#en" language string. I want to modify the triples so as to remove the language string from these triples and convert them to xsd:string.
I tried the query below. It doesn't report any errors and commits successfully.
DELETE { ?s ?p ?o }
INSERT { ?s ?p ?o2 }
WHERE
{
?s skos:notation ?o .
BIND(STRDT(STR(?o), xsd:string) AS ?o2)
}
However, the query does not result in any change to the triples data. Can anyone suggest where I might be going wrong?
Variable ?p in your query appears to be unbound. Try:
DELETE { ?s skos:notation ?o }
INSERT { ?s skos:notation ?o2 }
WHERE
{
?s skos:notation ?o .
BIND(STRDT(STR(?o), xsd:string) AS ?o2)
}
I want to edit a set of URIs replacing a substring "iso-693" with "iso-639" using a SPARQL query. I am using REPLACE but it doesn't seem to do anything.
I have a large SKOS taxonomy with URIs that have an incorrect string. They should have this string: "iso-639" but I made a mistake when creating it and put "iso-693". I'd like to correct it. I used the SPARQL query shown below, which when run returns a message "update successful", but none of the triples data actually changes. Where am I going wrong?
INSERT
{
?s ?p ?o2
}
WHERE
{
?s ?p ?o .
FILTER (regex(str(?s), "iso-693") || regex(str(?o), "iso-693"))
BIND(REPLACE(?o, "iso-693", "iso-639", "i") AS ?o2) .
}
I expected all of the occurrences of the substring to change to the desired value, but nothing seems to change at all despite the success message.
You are missing the bit that removes the old value (INSERT just adds a new triples). To replace a triple, you should DELETE the old triple at the same time as you are INSERTing the new one, like this:
DELETE
{
?s ?p ?o
}
INSERT
{
?s ?p ?o2
}
WHERE
{
?s ?p ?o .
FILTER (regex(str(?s), "iso-693") || regex(str(?o), "iso-693"))
BIND(REPLACE(?o, "iso-693", "iso-639", "i") AS ?o2) .
}
If you are targeting URIs then you need to construct new IRIs with the required substitution and use these in the INSERT part of the update along with the original values fro ?s and ?o for DELETE part. The REPLACE will produce Literals which is not correct fro subjects.
Suggest using something along following lines:
DELETE {
?s ?p ?o
}
INSERT {
?newS ?p ?newO
} WHERE {
?s ?p ?o .
bind("iso-693" as ?match) .
bind("iso-639" as ?replacement) .
bind (regex(str(?s), ?match) as ?subjMatch) .
bind (regex(str(?o), ?match) as ?objMatch) .
filter (?subjMatch || ?objMatch)
bind (if(?subjMatch, IRI(replace(str(?s), ?match, ?replacement)), ?s) as ?newS)
bind (if(?objMatch, IRI(replace(str(?o), ?match, ?replacement)), ?o) as ?newO)
}
PREFIX content: <http://example.com/content#>
construct { ?s content:field ?o}
WHERE { ?s content:field ?o }
90% of all the ?o I get here are the same URI <http://example.com/name>.
I'm trying to find a way to filter out all quads that have the same value for ?o, so in the end I get a list of quads which are unique by its ?o
I tried DISTINCT ?o CONSTRUCT{...} but from what I saw you cant use DISTINCT on a CONSTRUCT.
How would you filter the returned list of quads
I'm trying to find a way to filter out all quads that have the same
value for ?o, so in the end I get a list of quads which are unique by
its ?o
if it does not matter which exact value is bound to ?s, then a sub-select with a group by ?o is the way to go. Use (SAMPLE(?s) as ?subj) e.g. something like:
`
PREFIX content: <http://example.com/content#>
construct { ?s content:field ?o}
WHERE {
{ select ?o (SAMPLE(?subj) as ?s)
{ ?subj content:field ?o }
group by ?o
}
}
`
Let me start with an example query to explain my problem:
SELECT ?g ?s ?p ?o WHERE
{
{GRAPH ?g
{ ?s ?p ?o.
OPTIONAL{ ?s
ab:temperature ?temperature.}
FILTER (?temperature = 20)
FILTER NOT EXISTS {?s ab:person ?person}
}
}
}
This query gives me all graphs (in this case representing context data) that have a temperature of 20 but don't have a person associated. My problem is I want to query the graphs for certain optional properties but they shouldn't have any other properties. At the time of the query I only know the OPTIONAL part but I don't know which additional property might be there. Is there an easy way to do this with SPARQL or is that something that would be easier to check after I received the graph and converted it to an object which I can handle with my programm?
If i understand your question correctly, you are searching for graphs that only have that subjects with some properties but not others. In that case i'd run something like this:
SELECT ?g ?s ?p ?o WHERE {
GRAPH ?g {
?s ?p ?o.
FILTER NOT EXISTS {
?s ?bad [] .
FILTER (?bad NOT IN ( ab:temperature, ... ) )
}
}
}