Reputation: 1573
I'm busy with a proof of concept working with a triple store. I have the following structure:
There are 2 relation types defined (triples). Top-down relation where the child is part of ("isPartOf" its parent and left-right where there are childs that CAN (optional) be replaced ("replaces") by another version of the child.
Also every child have a "isValidStart" triple with a date as object. This means that this child is valid since that date. The last child in a horizontal childgroup can have a relation "isInvalidEnd" that means that after this date this group is invalid.
What I want to do is to build a SPARQL query where I can get the childs of a parent on a specific date. Is that possible with SPARQL and how can I do that?
I know that there is in Oracle any kind of START WITH / CONNECT BY function that do some kind of this stuff...but how do I this in SPARQL world.
Thanks
</metadata/puid/test2> <http://purl.org/dc/terms/isPartOf> "/metadata/puid/test1" .
</metadata/puid/test2> <http://purl.org/dc/terms/isValidStart> "2015-04-01"^^<http://www.w3.org/2001/XMLSchema#date> .
</metadata/puid/test3> <http://purl.org/dc/terms/isPartOf> "/metadata/puid/test2" .
</metadata/puid/test3> <http://purl.org/dc/terms/isValidStart> "2015-04-01"^^<http://www.w3.org/2001/XMLSchema#date> .
</metadata/puid/test4> <http://purl.org/dc/terms/isPartOf> "/metadata/puid/test3" .
</metadata/puid/test4> <http://purl.org/dc/terms/isValidStart> "2015-04-01"^^<http://www.w3.org/2001/XMLSchema#date> .
</metadata/puid/test5> <http://purl.org/dc/terms/isPartOf> "/metadata/puid/test4" .
</metadata/puid/test5> <http://purl.org/dc/terms/isValidStart> "2015-04-01"^^<http://www.w3.org/2001/XMLSchema#date> .
</metadata/puid/test6> <http://purl.org/dc/terms/isPartOf> "/metadata/puid/test4" .
</metadata/puid/test6> <http://purl.org/dc/terms/isValidStart> "2015-04-01"^^<http://www.w3.org/2001/XMLSchema#date> .
</metadata/puid/test7> <http://purl.org/dc/terms/isPartOf> "/metadata/puid/test4" .
</metadata/puid/test7> <http://purl.org/dc/terms/isValidStart> "2015-04-01"^^<http://www.w3.org/2001/XMLSchema#date> .
</metadata/puid/test8> <http://purl.org/dc/terms/replaces> "/metadata/puid/test7" .
</metadata/puid/test8> <http://purl.org/dc/terms/isValidStart> "2015-07-01"^^<http://www.w3.org/2001/XMLSchema#date> .
</metadata/puid/test9> <http://purl.org/dc/terms/isPartOf> "/metadata/puid/test5" .
</metadata/puid/test9> <http://purl.org/dc/terms/isValidStart> "2015-04-01"^^<http://www.w3.org/2001/XMLSchema#date> .
</metadata/puid/test10> <http://purl.org/dc/terms/isPartOf> "/metadata/puid/test5" .
</metadata/puid/test10> <http://purl.org/dc/terms/isValidStart> "2015-04-01"^^<http://www.w3.org/2001/XMLSchema#date> .
</metadata/puid/test11> <http://purl.org/dc/terms/isPartOf> "/metadata/puid/test5" .
</metadata/puid/test11> <http://purl.org/dc/terms/isValidStart> "2015-04-01"^^<http://www.w3.org/2001/XMLSchema#date> .
</metadata/puid/test12> <http://purl.org/dc/terms/replaces> "/metadata/puid/test9" .
</metadata/puid/test12> <http://purl.org/dc/terms/isValidStart> "2015-07-01"^^<http://www.w3.org/2001/XMLSchema#date> .
</metadata/puid/test13> <http://purl.org/dc/terms/replaces> "/metadata/puid/test10" .
</metadata/puid/test13> <http://purl.org/dc/terms/isValidStart> "2015-05-01"^^<http://www.w3.org/2001/XMLSchema#date> .
</metadata/puid/test14> <http://purl.org/dc/terms/replaces> "/metadata/puid/test13" .
</metadata/puid/test14> <http://purl.org/dc/terms/isValidStart> "2015-08-01"^^<http://www.w3.org/2001/XMLSchema#date> .
</metadata/puid/test14> <http://purl.org/dc/terms/isValidEnd> "2015-12-01"^^<http://www.w3.org/2001/XMLSchema#date> .
// disclaimer: I'm new in SPARQL world
Upvotes: 2
Views: 254
Reputation: 1573
I worked on a solution and I found a working solution. I put this method in a function that I can use to find the valid childs below that item (parent). I get a complete tree, with only valid items, when calling this function recursively.
PREFIX : <http://purl.org/dc/terms/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
SELECT ?child ?startDate ?endDate
WHERE
{
# get the valid start values
?child :isValidStart ?startDate
BIND(iri("'||$parent||'") as ?parent)
FILTER EXISTS{ {?child :isPartOf ?parent }
UNION {
?child (:replaces)+ ?prevVersion .
?prevVersion :isPartOf ?parent
}
}
# and there was no other valid replacing child
FILTER NOT EXISTS { ?replacer :replaces ?child ;
:isValidStart ?startDateReplacer
FILTER (?startDateReplacer <= "'||$selectionDate||'"^^xsd:date)
}
# where the start was before/at the given date
FILTER(?startDate <= "'||$selectionDate||'"^^xsd:date)
OPTIONAL { ?child :isValidEnd ?endDate }
# and not end date is before/at selection date
FILTER NOT EXISTS { FILTER (?endDate <= "'||$selectionDate||'"^^xsd:date) }
}
Upvotes: 1
Reputation: 8465
Not totally sure if this is what you're asking for but comments inline:
Given date: "2015-04-01"^^xsd:date
PREFIX : <http://purl.org/dc/terms/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
SELECT ?child
WHERE
{
# we have two options to check
# 1. all children that have not been replaced
{
# get the valid start values
?child :isValidStart ?start
# where the start was before the given date
FILTER ( ?start < "2015-04-01"^^xsd:date )
# and there was no other replacing child
FILTER NOT EXISTS { ?otherChild :replaces ?child }
}
UNION
# 2. children that haven been replaced
{
# start date of children that replace others
?child :isValidStart ?start ;
:replaces ?someChild
# but haven not been replaced themselves
FILTER NOT EXISTS { ?otherChild :replaces ?child }
# where the start was before the given date
FILTER(?start < "2015-04-01"^^xsd:date)
# and there isn't an end date before the given date
FILTER NOT EXISTS { ?child :isValidEnd ?end
FILTER ( ?end < "2015-04-01"^^xsd:date )
}
}
}
Upvotes: 2