RDF and ontology mappings: Difference between revisions

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Latest revision as of 23:14, 30 July 2026

Every NeoWiki page's Subjects are available as RDF. The same data is offered in two ways:

A native projection in NeoWiki's own vocabulary. Lossless, always available, no setup.
Ontology projections that re-express the data in an established vocabulary such as the Europeana Data Model (EDM). Each one is defined by a Mapping page.

Each export is produced on demand from the page's current data and downloads as a Turtle or TriG file. A projection can also be kept in a SPARQL store and queried live. This wiki has such a store: see SPARQL queries.

The Mapping page

Each Mapping page targets one ontology, named by the page title, and holds an entry for every mapped Schema. Special:Mappings lists them all; this wiki ships one:

Mapping:EDM: the Person, City, Artwork and Artist Schemas, all mapped to EDM

Explore the projections

Follow these in order; each link downloads the projection so you can read it.

You don't need these links to reach an export: on any subject page, the Data tab offers per-projection downloads (Turtle or TriG) and a copy-IRI control, and the sidebar has a View RDF link.

Pablo Picasso, native vs EDM: the native file has everything, including the two-layer "Born in" relation and the page metadata; the EDM file is an edm:Agent carrying only the mapped vocabulary, with the unmapped Source absent.
Málaga, EDM: an edm:Place with the very same entity IRI that Picasso's rdaGr2:placeOfBirth points at, because sibling projections share entity IRIs.
The Milkmaid, EDM: an edm:ProvidedCHO whose dc:creator is the IRI of Vermeer (an edm:Agent) and whose edm:currentLocation is the Rijksmuseum.
Johann Sebastian Bach, EDM: Bach's birth is modelled as its own Birth Subject instead of flat fields, so his edm:Agent projects sparse. Same Person Schema as Picasso, a different modelling style.
ACME Inc, EDM: its Company Schema has no EDM Mapping, so the EDM projection comes back empty. An unmapped Schema is simply left out, so the projection stays conformant.

Learn more

Special:Mappings: every ontology Mapping on this wiki
RDF export reference
Ontology mapping reference
Person-to-EDM worked example
Tell us what you need from RDF and ontology mapping: join the discussion.

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 * '''Ontology projections''' that re-express the data in an established vocabulary such as the [https://pro.europeana.eu/page/edm-documentation Europeana Data Model] (EDM). Each one is defined by a '''Mapping''' page.
-Each export is produced on demand from the page's current data and downloads as a Turtle or TriG file. A projection can also be kept in a SPARQL store and queried live — see [[SPARQL queries]] on wikis that have a store configured, such as the NeoWiki development stack.
+Each export is produced on demand from the page's current data and downloads as a Turtle or TriG file. A projection can also be kept in a SPARQL store and queried live. {{#ifexist:SPARQL queries|This wiki has such a store: see [[SPARQL queries]].}} {{#ifexist:EDM queries|The store holds the native and the EDM projection side by side, so a query can join across both — see [[EDM queries]].}}
 == The Mapping page ==
@@ Line 10: / Line 10: @@
 Each Mapping page targets one ontology, named by the page title, and holds an entry for every mapped Schema. [[Special:Mappings]] lists them all; this wiki ships one:
-* [[Mapping:EDM]] — the Person, City, Artwork and Artist Schemas, all mapped to EDM
+* [[Mapping:EDM]]: the Person, City, Artwork and Artist Schemas, all mapped to EDM
 == Explore the projections ==
 Follow these in order; each link downloads the projection so you can read it.
+You don't need these links to reach an export: on any subject page, the Data tab offers per-projection downloads (Turtle or TriG) and a copy-IRI control, and the sidebar has a View RDF link.
 # '''Pablo Picasso''', [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:Pablo Picasso}}/rdf native] vs [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:Pablo Picasso}}/rdf?projection=EDM EDM]: the native file has everything, including the two-layer "Born in" relation and the page metadata; the EDM file is an <code>edm:Agent</code> carrying only the mapped vocabulary, with the unmapped <code>Source</code> absent.
-# '''Málaga''', [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:Málaga}}/rdf?projection=EDM EDM]: an <code>edm:Place</code> — and the very same entity IRI that Picasso's <code>rdaGr2:placeOfBirth</code> points at, because sibling projections share entity IRIs.
+# '''Málaga''', [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:Málaga}}/rdf?projection=EDM EDM]: an <code>edm:Place</code> with the very same entity IRI that Picasso's <code>rdaGr2:placeOfBirth</code> points at, because sibling projections share entity IRIs.
 # '''The Milkmaid''', [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:The Milkmaid}}/rdf?projection=EDM EDM]: an <code>edm:ProvidedCHO</code> whose <code>dc:creator</code> is the IRI of [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:Johannes Vermeer}}/rdf?projection=EDM Vermeer] (an <code>edm:Agent</code>) and whose <code>edm:currentLocation</code> is the Rijksmuseum.
-# '''Johann Sebastian Bach''', [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:Johann Sebastian Bach}}/rdf?projection=EDM EDM]: Bach's birth is modelled as its own Birth Subject instead of flat fields, so his <code>edm:Agent</code> projects sparse — the same Person Schema as Picasso, a different modelling style.
+# '''Johann Sebastian Bach''', [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:Johann Sebastian Bach}}/rdf?projection=EDM EDM]: Bach's birth is modelled as its own [[Birth of Johann Sebastian Bach|Birth Subject]] instead of flat fields, so his <code>edm:Agent</code> projects sparse. Same Person Schema as Picasso, a different modelling style.
-# '''ACME Inc''', [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:ACME Inc}}/rdf?projection=EDM EDM]: its Company Schema has no EDM Mapping, so the EDM projection comes back empty — a Schema without a Mapping is simply absent, which is how conformant output stays conformant.
+# '''ACME Inc''', [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:ACME Inc}}/rdf?projection=EDM EDM]: its Company Schema has no EDM Mapping, so the EDM projection comes back empty. An unmapped Schema is simply left out, so the projection stays conformant.
 == Learn more ==
+* [[Special:Mappings]]: every ontology Mapping on this wiki
-* [https://github.com/ProfessionalWiki/NeoWiki/blob/master/docs/rdf/rdf-export.md RDF export reference]
-* [https://github.com/ProfessionalWiki/NeoWiki/blob/master/docs/rdf/ontology-mapping.md Ontology mapping reference]
+* [https://neowiki.ai/docs/rdf/rdf-export RDF export reference]
+* [https://neowiki.ai/docs/rdf/ontology-mapping Ontology mapping reference]
-* [https://github.com/ProfessionalWiki/NeoWiki/blob/master/docs/examples/person-to-edm.md Person-to-EDM worked example]
+* [https://neowiki.ai/docs/rdf/person-to-edm Person-to-EDM worked example]
 * Tell us what you need from RDF and ontology mapping: [https://github.com/ProfessionalWiki/NeoWiki/discussions/996 join the discussion].