Package org.aksw.jena_sparql_api.data_query.impl

Class QueryFragment

java.lang.Object
org.aksw.jena_sparql_api.data_query.impl.QueryFragment
public class QueryFragment extends Object
A query fragment is construct query with a designated variable. TODO Clarify whether there needs to be a join() function that injects a given element Component to retrieve additional attributes for a given concept In contrast to the BinaryRelation class, which uses designated source and target variables, this class allows mapping property paths to variables vie the template
Author:
Claus Stadler, May 27, 2018

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected org.apache.jena.sparql.core.Var
    conceptVar
     
    static org.apache.jena.rdf.model.Property
    facetCount
     
    protected org.apache.jena.query.Query
    query
     

  • Constructor Summary

    Constructors
    Constructor
    Description
    QueryFragment(org.apache.jena.sparql.core.Var conceptVar, org.apache.jena.query.Query query)
     

  • Method Summary

    Modifier and Type
    Method
    Description
    static void
    aggregate(QueryFragment queryFragment, org.apache.jena.sparql.path.Path path, org.apache.jena.sparql.expr.aggregate.Aggregator agg)
     
    static QueryFragment
    createForFacetCountRemainder(org.aksw.jenax.sparql.fragment.impl.Concept concept, boolean isReverse)
     
    static QueryFragment
    createForPredicate(org.apache.jena.graph.Node p, boolean isReverse)
     
    static org.apache.jena.graph.Triple
    createTriple(boolean isReverse, org.apache.jena.graph.Node s, org.apache.jena.graph.Node p, org.apache.jena.graph.Node o)
     
    static void
    extractFacetConstraints(org.apache.jena.query.Query query)
    - BGPs: BGPs are converted to Map<Path, Var> - TODO What to do with - forks in the path ?x foo [ bar ?y, baz ?z ] - multiple endpoints (a special case of a fork) - - Optional blocks are ignored as they are considered to correspond to the attribute part - i.e.
    static <P> org.apache.jena.sparql.core.Var
    getOrCreateAlias(P path, PathAccessorRdf<P> accessor, Map<P,org.aksw.jenax.sparql.fragment.api.Fragment2> pathToNode, Set<org.apache.jena.sparql.core.Var> forbiddenVars, org.aksw.commons.collections.generator.Generator<org.apache.jena.sparql.core.Var> varGen)
     
    static <P> void
    toElement(Iterable<P> paths, PathAccessorRdf<P> accessor, Set<org.apache.jena.sparql.syntax.Element> elements, Map<P,org.aksw.jenax.sparql.fragment.api.Fragment2> pathToNode, Set<org.apache.jena.sparql.core.Var> forbiddenVars, org.aksw.commons.collections.generator.Generator<org.apache.jena.sparql.core.Var> varGen)
    Create a query fragment that counts the number of distinct values for all properties.
    static <P> org.aksw.jenax.sparql.fragment.api.Fragment2
    toElement(P path, PathAccessorRdf<P> accessor, Map<P,org.aksw.jenax.sparql.fragment.api.Fragment2> pathToNode, Set<org.apache.jena.sparql.core.Var> forbiddenVars, org.aksw.commons.collections.generator.Generator<org.apache.jena.sparql.core.Var> varGen)
     
    String
    toString()
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

  • Field Details

    • conceptVar

      protected org.apache.jena.sparql.core.Var conceptVar

    • query

      protected org.apache.jena.query.Query query

    • facetCount

      public static org.apache.jena.rdf.model.Property facetCount

  • Constructor Details

    • QueryFragment

      public QueryFragment(org.apache.jena.sparql.core.Var conceptVar, org.apache.jena.query.Query query)

  • Method Details

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • createTriple

      public static org.apache.jena.graph.Triple createTriple(boolean isReverse, org.apache.jena.graph.Node s, org.apache.jena.graph.Node p, org.apache.jena.graph.Node o)

    • createForPredicate

      public static QueryFragment createForPredicate(org.apache.jena.graph.Node p, boolean isReverse)

    • extractFacetConstraints

      public static void extractFacetConstraints(org.apache.jena.query.Query query)
      - BGPs: BGPs are converted to Map<Path, Var> - TODO What to do with - forks in the path ?x foo [ bar ?y, baz ?z ] - multiple endpoints (a special case of a fork) - - Optional blocks are ignored as they are considered to correspond to the attribute part - i.e. they do not constrain the concept
      Parameters:
      query -

    • toElement

      public static <P> void toElement(Iterable<P> paths, PathAccessorRdf<P> accessor, Set<org.apache.jena.sparql.syntax.Element> elements, Map<P,org.aksw.jenax.sparql.fragment.api.Fragment2> pathToNode, Set<org.apache.jena.sparql.core.Var> forbiddenVars, org.aksw.commons.collections.generator.Generator<org.apache.jena.sparql.core.Var> varGen)
      Create a query fragment that counts the number of distinct values for all properties. The result is a map from each constrained property to its corresponding query fragment. The 'null' fragment is for all other properties. 
      
 # For each $constrainedProperty$:

 CONSTRUCT {
   ?p :facetCount ?c
 } WHERE {
   { SELECT ?p (COUNT(DISTINCT ?o) AS ?c {
   	$concept(?s)$
      $constraintElementWithout($constrainedProperty$)$
      ?s ?p ?o . # may be reversed
   	FILTER(?p = $constrainedProperty$)
   } GROUP BY ?p }
 }

    • getOrCreateAlias

      public static <P> org.apache.jena.sparql.core.Var getOrCreateAlias(P path, PathAccessorRdf<P> accessor, Map<P,org.aksw.jenax.sparql.fragment.api.Fragment2> pathToNode, Set<org.apache.jena.sparql.core.Var> forbiddenVars, org.aksw.commons.collections.generator.Generator<org.apache.jena.sparql.core.Var> varGen)

    • toElement

      public static <P> org.aksw.jenax.sparql.fragment.api.Fragment2 toElement(P path, PathAccessorRdf<P> accessor, Map<P,org.aksw.jenax.sparql.fragment.api.Fragment2> pathToNode, Set<org.apache.jena.sparql.core.Var> forbiddenVars, org.aksw.commons.collections.generator.Generator<org.apache.jena.sparql.core.Var> varGen)

    • aggregate

      public static void aggregate(QueryFragment queryFragment, org.apache.jena.sparql.path.Path path, org.apache.jena.sparql.expr.aggregate.Aggregator agg)

    • createForFacetCountRemainder

      public static QueryFragment createForFacetCountRemainder(org.aksw.jenax.sparql.fragment.impl.Concept concept, boolean isReverse)