GraphQL is a popular JSON-like query language for graph-based data that can now be used to query Linked Data by converting GraphQL queries to SPARQL queries using a JSON-LD context. This allows GraphQL developers to query any SPARQL engine but GraphQL queries only have semantics over a single interface, whereas GraphQL queries combined with JSON-LD have universal semantics that enable federated querying over multiple Linked Data sources.

1. Ruben.Taelman@UGent.be
@rubensworks
Query the Web of Linked Data with GraphQL queries
Highly popular JSON-like query language for graph-based data
We convert GraphQL queries to SPARQL using a JSON-LD context
LD-
Can only be used to query a single GraphQL interface
no link with Semantic Web technologies
Try it at http://query.linkeddatafragments.org/
GraphQL Query
JSON-LD Context
{
label
}
{
“label”: “http://www.w3.org/1999/02/22-rdf-syntax-ns#”
}
+
= SELECT ?label
WHERE {
_:b <http://www.w3.org/1999/02/22-rdf-syntax-ns#label> ?label
}
SPARQL Query
GraphQL developers can now query with any SPARQL engine.
=> no universal semantics over different interfaces
GraphQL-LD queries have universal semantics,
which enables federated querying over multiple sources.