Struct PreparedSparqlQuery 

pub struct PreparedSparqlQuery {
    evaluator: QueryEvaluator,
    query: Query,
    dataset: QueryDatasetSpecification,
    substitutions: HashMap<Variable, Term>,
}

Available on crate feature rdf only.

A prepared SPARQL query.

Allows customizing things like the evaluation dataset and substituting variables.

Usage example:

use oxigraph::model::{Literal, Variable};
use oxigraph::sparql::{QueryResults, SparqlEvaluator};
use oxigraph::store::Store;

let prepared_query = SparqlEvaluator::new()
    .parse_query("SELECT ?v WHERE {}")?
    .substitute_variable(Variable::new("v")?, Literal::from(1));

if let QueryResults::Solutions(mut solutions) =
    prepared_query.on_store(&Store::new()?).execute()?
{
    assert_eq!(
        solutions.next().unwrap()?.get("v"),
        Some(&Literal::from(1).into())
    );
}

Fields

evaluator: QueryEvaluator

query: Query

dataset: QueryDatasetSpecification

substitutions: HashMap<Variable, Term>

Implementations

impl PreparedSparqlQuery

pub fn substitute_variable( self, variable: impl Into<Variable>, term: impl Into<Term>, ) -> PreparedSparqlQuery

Substitute a variable with a given RDF term in the SPARQL query.

Usage example:

use oxigraph::model::{Literal, Variable};
use oxigraph::sparql::{QueryResults, SparqlEvaluator};
use oxigraph::store::Store;

let prepared_query = SparqlEvaluator::new()
    .parse_query("SELECT ?v WHERE {}")?
    .substitute_variable(Variable::new("v")?, Literal::from(1));

if let QueryResults::Solutions(mut solutions) =
    prepared_query.on_store(&Store::new()?).execute()?
{
    assert_eq!(
        solutions.next().unwrap()?.get("v"),
        Some(&Literal::from(1).into())
    );
}

pub fn dataset(&self) -> &QueryDatasetSpecification

Returns the query dataset specification of this prepared query.

pub fn dataset_mut(&mut self) -> &mut QueryDatasetSpecification

Returns the query dataset specification of this prepared query.

pub fn on_store(self, store: &Store) -> BoundPreparedSparqlQuery<'static>

Bind the prepared query to the [Store] it should be evaluated on.

pub fn on_transaction<'b>( self, transaction: &'b Transaction<'_>, ) -> BoundPreparedSparqlQuery<'b>

Bind the prepared query to the [Transaction] it should be evaluated on.

pub fn on_queryable_dataset<'a, D>( self, queryable_dataset: D, ) -> BoundPreparedSparqlQuery<'a, D>

where D: QueryableDataset<'a>,

Bind the prepared query to the [QueryableDataset] it should be evaluated on.

Trait Implementations

impl Clone for PreparedSparqlQuery

fn clone(&self) -> PreparedSparqlQuery

Returns a duplicate of the value.

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

Performs copy-assignment from source.