#
# example SPARQL query 166
#

@prefix schema: <https://schema.org/> . 
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> . 
@prefix sh: <http://www.w3.org/ns/shacl#> . 
@prefix cello: <https://purl.expasy.org/cellosaurus/rdf/ontology/> .


cello:Query_166 a sh:SPARQLExecutable ;
    sh:prefixes _:sparql_examples_prefixes ;
    rdfs:comment """Example (sample) of a cross-reference with its properties from each database"""@en ; 
    schema:keywords "dr" , "xref" , "disc" , "discontinued" ; 
    schema:target <https://sparql.cellosaurus.org/sparql> ; 
    sh:select """
PREFIX cello: <https://purl.expasy.org/cellosaurus/rdf/ontology/>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX owl: <http://www.w3.org/2002/07/owl#>
select ?db_class ?db (sample(?ac) as ?sample_ac) (sample(?disc) as ?sample_disc) (sample(?lbl) as ?sample_label) (sample(?url) as ?sample_url) where {
  ?xref a cello:Xref .
  ?xref cello:database ?db.
  ?xref cello:accession ?ac.
  ?db a ?db_class .
  ?db_class rdfs:subClassOf cello:Database . # (useful to get rid of irrelevant owl:NamedIndividual)
  optional { ?xref cello:discontinued ?disc  }.
  optional { ?xref rdfs:label ?lbl  }.
  optional { ?xref rdfs:seeAlso ?url } .
  # filter (bound(?disc))  # uncomment to see xrefs identifying a discontinued product reference in a catalog
  # filter (bound(?lbl))   # uncomment to see xrefs having a label (genes, chemicals, anatomy, ...)
  # filter (! bound(?url)) # uncomment to see xrefs having NO url (discontinued products, ...)
}
group by ?db_class ?db
order by ?db_class ?db
limit 300
    """
    .