sparql-http-client

sparql-http-client

SPARQL client for easier handling of SPARQL Queries and Graph Store requests. The SPARQL Protocol is used for SPARQL Queries and SPARQL Updates. The SPARQL Graph Store Protocol is used to manage Named Graphs.

It provides client implementations in different flavors. The default client comes with an interface for streams, the simple client is closer to fetch, and the parsing client wraps the results directly into RDF/JS DatasetCore objects or arrays.

Usage

The example below shows how to use the client to run a SELECT query against the Wikidata endpoint. Check the documentation for more details.

import SparqlClient from 'sparql-http-client'

const endpointUrl = 'https://query.wikidata.org/sparql'
const query = `
PREFIX wd: <http://www.wikidata.org/entity/>
PREFIX p: <http://www.wikidata.org/prop/>
PREFIX ps: <http://www.wikidata.org/prop/statement/>
PREFIX pq: <http://www.wikidata.org/prop/qualifier/>

SELECT ?value WHERE {
  wd:Q243 p:P2048 ?height.

  ?height pq:P518 wd:Q24192182;
    ps:P2048 ?value .
}`

const client = new SparqlClient({ endpointUrl })
const stream = client.query.select(query)

stream.on('data', row => {
  for (const [key, value] of Object.entries(row)) {
    console.log(`${key}: ${value.value} (${value.termType})`)
  }
})

stream.on('error', err => {
  console.error(err)
})