remote-sparql#

The remote-sparql command allows executing SPARQL queries on a remote server endpoint.

Usage:

corese-command remote-sparql [-hivw] [-q=<queryUrlOrFile>]
                             [-d=<default_graph>...] [-n=<named_graph>...]
                             [-m=<requestMethod>]  [-a=<accept>] [-H=<headers>...]
                             [-r=<maxRedirection>] [-o=<output>]
                             [-c=<configFilePath>]
                             -e=<endpoint_url>

Options and arguments:

  • -e, --endpoint <string|path|URL> : Required URL of a SPARQL endpoint.

  • -q, --query <string|path|URL> : Required SPARQL query string or path/URL to a .rq file

  • -d, --default-graph <string> : Optional default graph URI. Can be specified multiple times. The default graph URIs form the FROM clause.

  • -n, --named-graph <string> : Optional named graph URI. Can be specified multiple times. The named graph URIs form the FROM NAMED clause.

  • -i, –ignore-query-validation: Optional flag to forgo query syntax validation before it is sent to a remote server. Default: false.

  • -m, --request-method <get|post-urlencodedEncoded|post-direct> : HTTP request method, post-urlencoded is equivalent to POST request with Content-Type:application/x-www-form-urlencoded header. POST-Direct is equivalent to POST request with Content-Type:application/sparql-query header. Default method: get.

  • -a, -of, --accept <string> : Accept header value which is also an output format. Supported values are listed below Default: text/csv.

  • -H, --header <string> : Any additional HTTP header to add to the request. Default: none.

  • -r, --max-redirection <int> : Maximum number of response redirection. Default: 5.

  • -o, --output-data <output_file> : Optional path to save the query results. Default: standard output.

  • -c, --config, --init <path> : Optional path to the configuration file.

  • -w, --no-owl-import : Disables the automatic import of referenced ontologies specified in ‘owl:imports’ statements in the profile.ttl file. Default: enabled.

  • -v, --verbose : Display verbose output.

  • -h, --help: Display sparql command options.

Example:

In this example we access the demo endpoint of the Corese server and execute a simple SPARQL query to retrieve all the children and their mothers in the dataset.

QUERY='PREFIX  humans: <http://www.inria.fr/2015/humans#>
       SELECT * WHERE { ?child humans:hasMother ?mother. }'

corese-command remote-sparql -e http://corese.inria.fr/sparql \
                             -q "$QUERY"

child,mother
http://www.inria.fr/2015/humans-instances#Lucas,http://www.inria.fr/2015/humans-instances#Catherine
http://www.inria.fr/2015/humans-instances#Catherine,http://www.inria.fr/2015/humans-instances#Laura

For more examples, see the Getting Started Guide.

Output (Accept) formats#

Output formats depend on the endpoint implementation and the query form. If the remote endpoint is also powered by Corese then the following formats are supported:

SELECT, ASK:

  • XML: application/sparql-results+xml

  • Json: application/sparql-results+json

  • CSV: text/csv

  • TSV: text/tab-separated-values

CONSTRUCT, DESCRIBE:

  • RDF/XML: rdfxm`application/rdf+xml

  • Turtle: text/turtle

  • TriG: application/trig

  • JSON-LD: application/ld+json

  • NTRIPLES: application/n-triples

  • NQUADS: application/n-quads