rdf-r2rml

R2RML materialisation for the ZuzuScript rdf distribution.

This distribution provides rdf/r2rml, which can populate an RDFStore from a std/db database handle using an R2RML mapping. Mapping input may be pre-parsed RDF quads or serialized RDF parsed by a parser object from the main rdf framework. Turtle is used by default.

Direct Mapping is intentionally not implemented here; Rowquill already supports that shape.

Example

from rdf/r2rml import r2rml_materialize;
from rdf/store import RDFStore;
from std/db import DB;

let dbh := DB.temp();
dbh.prepare( "create table people (id integer, name text)" ).execute();
dbh.prepare( "insert into people (id, name) values (1, 'Ada')" ).execute();

let store := RDFStore.temp();
store.install_schema();

r2rml_materialize( dbh, """
@prefix rr: <http://www.w3.org/ns/r2rml#> .
@prefix ex: <http://example.com/> .

<#People>
	rr:logicalTable [ rr:tableName "people" ];
	rr:subjectMap [
		rr:template "http://example.com/person/{id}";
		rr:class ex:Person;
	];
	rr:predicateObjectMap [
		rr:predicate ex:name;
		rr:objectMap [ rr:column "name" ];
	].
""", into: store );

Current Scope

The implementation is built against R2RML and the W3C R2RML test cases. It currently supports logical tables from rr:tableName and rr:sqlQuery, subject maps, predicate-object maps, constant/column/template term maps, classes, named graphs, datatypes, language tags, and basic referencing object maps.

The R2RML cases from the W3C RDB2RDF suite are vendored under tests/w3c/rdb2rdf and run by tests/w3c-r2rml.zzs, covering 50 positive cases and 13 invalid mappings. Direct Mapping is out of scope for this distribution.