Struct QueryOptions

pub struct QueryOptions { /* private fields */ }

Options for SPARQL query evaluation.

If the "http-client" optional feature is enabled, a simple HTTP 1.1 client is used to execute SPARQL 1.1 Federated Query SERVICE calls.

Usage example disabling the federated query support:

use oxigraph::sparql::QueryOptions;
use oxigraph::store::Store;

let store = Store::new()?;
store.query_opt(
    "SELECT * WHERE { SERVICE <https://query.wikidata.org/sparql> {} }",
    QueryOptions::default().without_service_handler(),
)?;

Implementations

impl QueryOptions

pub fn with_service_handler( self, service_handler: impl ServiceHandler + 'static, ) -> Self

Use a given ServiceHandler to execute SPARQL 1.1 Federated Query SERVICE calls.

pub fn without_service_handler(self) -> Self

Disables the SERVICE calls

pub fn with_custom_function( self, name: NamedNode, evaluator: impl Fn(&[Term]) -> Option<Term> + Send + Sync + 'static, ) -> Self

Adds a custom SPARQL evaluation function.

Example with a function serializing terms to N-Triples:

use oxigraph::model::*;
use oxigraph::sparql::{QueryOptions, QueryResults};
use oxigraph::store::Store;

let store = Store::new()?;

if let QueryResults::Solutions(mut solutions) = store.query_opt(
    "SELECT (<http://www.w3.org/ns/formats/N-Triples>(1) AS ?nt) WHERE {}",
    QueryOptions::default().with_custom_function(
        NamedNode::new("http://www.w3.org/ns/formats/N-Triples")?,
        |args| args.get(0).map(|t| Literal::from(t.to_string()).into()),
    ),
)? {
    assert_eq!(
        solutions.next().unwrap()?.get("nt"),
        Some(&Literal::from("\"1\"^^<http://www.w3.org/2001/XMLSchema#integer>").into())
    );
}

Trait Implementations

impl Clone for QueryOptions

fn clone(&self) -> QueryOptions

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Default for QueryOptions

fn default() -> QueryOptions

Returns the “default value” for a type.

impl From<QueryOptions> for UpdateOptions

fn from(query_options: QueryOptions) -> Self

Converts to this type from the input type.