barnard59-tdb

barnard59-tdb

SPARQL data processing support for Barnard59 Linked Data pipelines using Jena TDB. All operations provide a readable and writable stream interface. The Writable stream expects RDFJS quads. All incoming quads will be written to a temporary TDB database. A database dump or the result of the query will be written to the readable stream.

Operations

construct

Runs a construct query and returns the result as a RDFJS quad stream.

• query: The SPARQL construct query as a string.

select

Runs a select query and returns each row of the results as single chunk object. The chunk object contains key-value pairs for each variable of the select query.

• query: The SPARQL select query as a string.

update

Runs multiple update queries and returns a database dump as a RDFJS quad stream.

• queries: SPARQL update queries as an array of strings.

Examples

update

The example pipeline in examples/update.ttl parses the pipeline description in the update.ttl file and feeds it to the TDB update operation. Two queries are used. All examples/update.ttl literals are updated to examples/outdated.ttl in the first query. And again changed to examples/update.ttl in the second query. The TDB data is then serialized to N-Triples and the barnard59 command line tool writes it to stdout.
The example can be run with the following command:

./node_modules/.bin/barnard59 run --format=text/turtle --pipeline=http://example.org/pipeline#pipeline --verbose examples/update.ttl