import * as sparql from '@okikio/sparql'

const query = sparql.select(['?name'])
  .prefix('schema', 'https://schema.org/')
  .where(sparql.triple('?thing', 'schema:name', '?name'))

Syntax roles #

The API keeps complete documents separate from embeddable syntax:

SparqlTermType     term or legal property-path position
SparqlExprType     expression
PatternValueType   graph-pattern fragment
SparqlQueryType    complete query document
SparqlUpdateType   complete Update document

This prevents a complete query/update from being accepted where the SPARQL grammar requires a term, expression, or WHERE fragment.

RDF and generated vocabulary terms #

IRI-bearing positions accept native RDF named nodes. Generated vocabulary values therefore compose directly without making this package depend on @okikio/vocab:

import * as rdf from '@okikio/rdf'
import * as sparql from '@okikio/sparql'
import { name, offers, price, Product } from '@okikio/vocab/schema'

const query = sparql.select(['?product', '?name']).where(
  sparql.triple('?product', rdf.namedNode(rdf.RDF.type), Product),
  sparql.triple('?product', name, '?name'),
)

The same RDF terms work in property paths, graph/update IRIs, datatypes, and prefix declarations:

const path = sparql.sequence(offers, price)
const text = sparql.typed('42', rdf.namedNode(rdf.XSD.integer))
const update = sparql.update().clear(rdf.namedNode('urn:graph:old')).build()

Strict IRI positions reject variable/literal SparqlTermType values at runtime instead of trusting any branded term as an IRI.

Execution #

Execution is separate. Use @okikio/sparql/http, @okikio/oxigraph, @okikio/comunica, or another implementation of Queryable.

interface Queryable {
  queryBindings(...): Promise<AsyncIterable<BindingType>>
  queryQuads(...): Promise<AsyncIterable<rdf.Quad>>
  queryBoolean(...): Promise<boolean>
  update(...): Promise<void>
}

update() is the public update operation. A concrete upstream engine can use a different internal method name; for example, Comunica currently exposes queryVoid(), which its adapter translates to update().

See ../../docs/sparql-mapping.md.

@okikio/sparql #

Syntax roles #

RDF and generated vocabulary terms #

Execution #

`@okikio/sparql` #