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