Construct loop in SPARQL

Question

The following SPARQL query

PREFIX owl: <http://www.w3.org/2002/07/owl#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
prefix skos: <http://www.w3.org/2004/02/skos/core#>
prefix msc: <http://msc.org/resources/MSC/msc2020/>

construct {?s skos:broader msc:00-XX . }
where
{
?s a skos:Concept ; skos:notation ?notation.
filter regex (?notation, "00-\d\d")
}

searches all notations 00-01, 00-02, etc. and constructs a relation to the top level class 00-XX. However, this is only the first of 63 top level classes altogether, so I would like to "loop" over all top level classes automatically. On top, I would like to adapt this to other patterns. Is there a way to do this with SPARQL? If not, what would you recommend instead?

Answer 1

In the meantime we found a solution without SPARQL. The SPARQL CONSTRUCT query was supposed to create a skos:broader relation between a skos:Concept with a notation like "00-01" (and all other concepts with 00-\d\d notation) and its proper subordinate concept, which for 00-01 is the skos:Concept with the notation 00-XX.

The data originate from a table and Open Refine is much faster in creating the skos:broader statements than using the SPARQL query proposed above and adjusting it to other notation patterns.

We use GREL's value.replace on the cells with the notations to create a new column:

value.replace(/-\d\d/, "-XX").replace(/\d\d>/, "xx>")

The two replacements give us the notation of the original notation's superordinate concept in one step. The second replace already adapts to the other patterns mentioned in the question (eg 00A01). With the original notation and the value in the new column, we can easily create the skos:broader triples by concatenating text and the values from both columns. These can then be exported from OpenRefine and just be copy-pasted to our SKOS vocabulary.

Answer 2

Here is a SPARQL answer based on the query in the question. Using filters and regex (as suggested in the comment by Yahalnaut as a reply to UninforomedUser above) is needed. Creating a skos:broader relation based on two concept's notations requires them to hava an identical sequence of digits before the - . The comparison should only between the first part of the notations, so each 00- should match another 00- but not a 01- . As asked, the solution below only considers topConcepts of the Vocabulary as potential objects for skos:broader. The concepts should also not relate to themselves, therefore the last filter. This should then be adoptable to other patterns as well. Depending on the number of Concepts and the memory available for the query, this may last a while or even stop before finished. It eliminates lot of the effort though.

PREFIX owl: <http://www.w3.org/2002/07/owl#> 
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> 
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
prefix skos: <http://www.w3.org/2004/02/skos/core#> 
prefix msc: <http://msc.org/resources/MSC/msc2020/>  


construct {?s skos:broader ?y . } 
where { 
?s a skos:Concept ; skos:notation ?notation. 
?y skos:topConceptOf msc: ; skos:notation ?not2. 
bind (REPLACE (?not2 , "-XX" , "") as ?1)
bind  (REPLACE (?notation , "-\d\d", "" ) as ?2 )
filter (?1 = ?2)
filter (?not2 != ?notation)
}