Result formats

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By default, Comunica has support for the following result formats:

Media type	Description
`application/json`	A custom, simplified JSON result format.
`simple`	A custom, text-based result format.
`application/sparql-results+json`	The SPARQL/JSON results format.
`application/sparql-results+xml`	The SPARQL/XML results format.
`text/csv`	The SPARQL/CSV results format.
`text/tab-separated-values`	The SPARQL/TSV results format.
`stats`	A custom results format for testing and debugging.
`table`	A text-based visual table result format.
`tree`	A tree-based result format for GraphQL-LD result compacting.
`application/trig`	The TriG RDF serialization.
`application/n-quads`	The N-Quads RDF serialization.
`text/turtle`	The Turtle RDF serialization.
`application/n-triples`	The N-Triples RDF serialization.
`text/n3`	The Notation3 serialization.
`application/ld+json`	The JSON-LD RDF serialization.

Querying from the command line

When using Comunica from the command line, the result format can be set using the -t option:

$ comunica-sparql https://fragments.dbpedia.org/2016-04/en \
    "SELECT * WHERE { ?s ?p ?o } LIMIT 100" \
    -t "application/sparql-results+json"

{"head": {"vars":["s","p","o"]},
"results": { "bindings": [
{"s":{"value":"http://0-access.newspaperarchive.com.lib.utep.edu/us/mississippi/biloxi/biloxi-daily-herald/1899/05-06/page-6?tag=tierce+wine&rtserp=tags/tierce-wine?page=2","type":"uri"},"p":{"value":"http://dbpedia.org/property/date","type":"uri"},"o":{"value":"1899-05-06","type":"literal","datatype":"http://www.w3.org/2001/XMLSchema#date"}},
{"s":{"value":"http://0-access.newspaperarchive.com.lib.utep.edu/us/mississippi/biloxi/biloxi-daily-herald/1899/05-06/page-6?tag=tierce+wine&rtserp=tags/tierce-wine?page=2","type":"uri"},"p":{"value":"http://dbpedia.org/property/isCitedBy","type":"uri"},"o":{"value":"http://dbpedia.org/resource/Tierce_(unit)","type":"uri"}},
{"s":{"value":"http://0-access.newspaperarchive.com.lib.utep.edu/us/mississippi/biloxi/biloxi-daily-herald/1899/05-06/page-6?tag=tierce+wine&rtserp=tags/tierce-wine?page=2","type":"uri"},"p":{"value":"http://dbpedia.org/property/newspaper","type":"uri"},"o":{"value":"Biloxi Daily Herald","type":"literal"}},
{"s":{"value":"http://0-access.newspaperarchive.com.lib.utep.edu/us/mississippi/biloxi/biloxi-daily-herald/1899/05-06/page-6?tag=tierce+wine&rtserp=tags/tierce-wine?page=2","type":"uri"},"p":{"value":"http://dbpedia.org/property/page","type":"uri"},"o":{"value":"6","type":"literal"}},
{"s":{"value":"http://0-access.newspaperarchive.com.lib.utep.edu/us/mississippi/biloxi/biloxi-daily-herald/1899/05-06/page-6?tag=tierce+wine&rtserp=tags/tierce-wine?page=2","type":"uri"},"p":{"value":"http://dbpedia.org/property/title","type":"uri"},"o":{"value":"A New System of Weights and Measures","type":"literal"}},
{"s":{"value":"http://0-access.newspaperarchive.com.lib.utep.edu/us/mississippi/biloxi/biloxi-daily-herald/1899/05-06/page-6?tag=tierce+wine&rtserp=tags/tierce-wine?page=2","type":"uri"},"p":{"value":"http://dbpedia.org/property/url","type":"uri"},"o":{"value":"http://0-access.newspaperarchive.com.lib.utep.edu/us/mississippi/biloxi/biloxi-daily-herald/1899/05-06/page-6?tag=tierce+wine&rtserp=tags/tierce-wine?page=2","type":"uri"}},
...

All available formats can be printed via comunica-sparql --listformats

Querying in a JavaScript app

When using Comunica in a JavaScript application, results can be serialized to a certain format using resultToString():

const result = await myEngine.query(`
  SELECT ?s ?p ?o WHERE {
    ?s ?p <http://dbpedia.org/resource/Belgium>.
    ?s ?p ?o
  } LIMIT 100`, {
  sources: ['http://fragments.dbpedia.org/2015/en'],
});
const { data } = await myEngine.resultToString(result,
  'application/sparql-results+json');
data.pipe(process.stdout); // Print to standard output

The resultToString() method accepts a query result and a result format media type. The media type is optional, and will default to application/json for bindings, application/trig for quads, and simple for booleans.

All available result formats can be retrieved programmatically by invoking the asynchronous getResultMediaTypes() method.