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Counting Union of Two Restrictions in SPARQL Queries

·Jan 23, 2023 09:09 PM

SPARQL question— is it possible to do a COUNT command on the union of two restrictions? Here is the query syntax.

10 comments

· Sorted by Oldest

Ricardo U.
·
Hi, sure, that should work. Do you get an error?
👍1
Leia D.
·
No. The result isn’t giving me what I expect. One query solo gives me 156, the other solo 190. When I run them as a Union, I get 156. Given that, I feel like I should get a different number.
Ricardo U.
·
I do not see the closing brackets, could be the source of error. My guess is that ?x is always bound in the first UNION and thus you would need to reformulate to use OPTIONAL instead of UNION and move ?x rdf:type ?restriction outside
Nikos T.
·
If you want a simple count you could remove the union and change the last triple to something like this:
?restriction owl:someValuesFrom ?itemOneOrItemTwo . FILTER(?itemOneOrItemTwo IN (gfo:itemOne, gfo:itemTwo))
This way you can add/remove values as needed.
✅1
Leia D.
·
Thank you! I’ll try this.
Leia D.
·
Unfortunately, this didn’t work but I think it’s because of the issue on our end. The classes in question have a class/subclass relationship. So I think I’ll have to try something else… but I think this works if classes are sibling classes.

·

Why are you trying to use this query, rather than simply:

SELECT (COUNT(DISTINCT ?x) AS ?nox)
WHERE {
VALUES ?topClass {gfo:itemOne gfo:itemTwo}
?x gfo:involves/rdf:type ?topClass
}

Or also:

SELECT (COUNT(DISTINCT ?x) AS ?nox)
WHERE {
{?x gfo:involves/rdf:type gfo:itemOne}
UNION
{?x gfo:involves/rdf:type gfo:itemTwo}
}

Leia D.
·
Thank you. I’ll try this next time…
Valerio C.
·
Did you end up finding another solution or just gave up?
Leia D.
·
I found a workaround.