Mapping Example

This example follows in an excerpt from an actual mapping of the phpBB3 SQL schema to the classes defined by the SIOC and FOAF ontologies:

-- SPARQL keyword which is the SPARQL cue for the SQL processor

SPARQL

-- PREFIX declarations

PREFIX  sioc:  <http://rdfs.org/sioc/ns#>
PREFIX  sioct: <http://rdfs.org/sioc/types#>
PREFIX  atom:  <http://atomowl.org/ontologies/atomrdf#>
PREFIX  rdfs:  <http://www.w3.org/2000/01/rdf-schema#>
PREFIX  foaf:  <http://xmlns.com/foaf/0.1/>
PREFIX  dc:    <http://purl.org/dc/elements/1.1/>
PREFIX  dct:   <http://purl.org/dc/terms/>
PREFIX  skos:  <http://www.w3.org/2004/02/skos/core#>
PREFIX  geo:   <http://www.w3.org/2003/01/geo/wgs84_pos#>
PREFIX  bm:    <http://www.w3.org/2002/01/bookmark#>
PREFIX  exif:  <http://www.w3.org/2003/12/exif/ns/>
PREFIX  ann:   <http://www.w3.org/2000/10/annotation-ns#>
PREFIX  phpbb: <http://openlinksw.com/phpBB3/>

-- Remove prior mappings 
DROP QUAD MAP GRAPH IRI ("http://^{URIQADefaultHost}^/phpBB3_v/") .

-- Declare the special Virtuoso-URI-Generator functions for later use in actual mappings

CREATE IRI CLASS  phpbb:site_iri     
  "http://^{URIQADefaultHost}^/phpBB3/%U#this" 
    ( IN  dummy       VARCHAR NOT NULL ) .
CREATE IRI CLASS  phpbb:user_iri
  "http://^{URIQADefaultHost}^/phpBB3/user/%U#this" 
    ( IN  user_name   INTEGER NOT NULL ) .
CREATE IRI CLASS  phpbb:usergroup_iri
  "http://^{URIQADefaultHost}^/phpBB3/group/%U#this" 
    ( IN  group_name  INTEGER NOT NULL ) .
CREATE IRI CLASS  phpbb:forum_iri
  "http://^{URIQADefaultHost}^/phpBB3/forum/%d#this" 
    ( IN  forum_id    INTEGER NOT NULL ) .
CREATE IRI CLASS  phpbb:post_iri
  "http://^{URIQADefaultHost}^/phpBB3/post/%d#this" 
    ( IN  post_id     INTEGER NOT NULL ) .

-- Start the actual mapping declaration process
-- Identify Quad Storage Partition within Quad Store

ALTER QUAD STORAGE virtrdf:DefaultQuadStorage
  {

-- Declare Named Graph URI / IRI associated with previously declared Quad Storage partition

    CREATE virtrdf:phpBB3 AS GRAPH IRI ("http://^{URIQADefaultHost}^/phpBB3_v/")
      {

-- Use SPARQL / Turtle Graph patterns to declare:
-- mappings between Table and a RDF Schema or Ontology Class
   # Default phpBB Space
   phpbb:site_iri (PHPBB3.phpBB.phpBB3_site_rdf.WS_DUMMY)
   a sioc:Space ;

--- mappings between Columns in a Table with Attributes of a RDF Schema or Ontology Class
   dc:title WEB_TITLE .

-- The combined data from each mapped column (row) is used to generate an instance (Entity/Individual) of this RDF Schema or Ontology Class 
-- Repeat the process for Each Table being mapped

   # User
   phpbb:user_iri (PHPBB3.phpBB.phpBB3_users_rdf.username)
     a                sioc:User ;
     sioc:id          user_id ;
     sioc:name        username ;
     sioc:email       E_MAIL ;
     sioc:email_sha1  E_MAIL_SHA1 ;
     sioc:has_space   phpbb:site_iri(WS_DUMMY) .

   # Usergroup
   phpbb:usergroup_iri (PHPBB3.phpBB.phpBB3_usergroups_rdf.group_name)
     a          sioc:Usergroup ;
     sioc:id    group_id ;
     sioc:name  group_name .
        .....