Struct RdfFusionLogicalPlanBuilder 

pub struct RdfFusionLogicalPlanBuilder { /* private fields */ }

A convenient builder for programmatically creating SPARQL queries.

Example

let subject = Variable::new_unchecked("s");
let predicate = Variable::new_unchecked("p");
let object = Variable::new_unchecked("o");

let pattern = TriplePattern {
    subject: TermPattern::Variable(subject.clone()),
    predicate: NamedNodePattern::Variable(predicate),
    object: TermPattern::Variable(object),
};

let builder_context = RdfFusionLogicalPlanBuilderContext::new(rdf_fusion_context);
let plan: LogicalPlan = builder_context
    .create_pattern(ActiveGraph::DefaultGraph, None, pattern)
    .project(&[subject])
    .unwrap()
    .build()
    .unwrap();

Implementations

impl RdfFusionLogicalPlanBuilder

pub fn project( self, variables: &[Variable], ) -> Result<RdfFusionLogicalPlanBuilder, DataFusionError>

Projects the current plan to a new set of variables.

pub fn filter( self, expression: Expr, ) -> Result<RdfFusionLogicalPlanBuilder, DataFusionError>

Applies a filter using expression.

The filter expression is evaluated for each solution. If the effective boolean value of the expression is true, the solution is kept; otherwise, it is discarded.

If the expression does not evaluate to a boolean, its effective boolean value is determined according to SPARQL rules.

Relevant Resources

• SPARQL 1.1 - Effective Boolean Value (EBV)

pub fn extend( self, variable: Variable, expr: Expr, ) -> Result<RdfFusionLogicalPlanBuilder, DataFusionError>

Extends the current plan with a new variable binding.

pub fn join( self, rhs: LogicalPlan, join_type: SparqlJoinType, filter: Option<Expr>, ) -> Result<RdfFusionLogicalPlanBuilder, DataFusionError>

Creates a join node of two logical plans that contain encoded RDF Terms.

Relevant Resources

• SPARQL 1.1 - Compatible Mappings

pub fn slice( self, start: usize, length: Option<usize>, ) -> Result<RdfFusionLogicalPlanBuilder, DataFusionError>

Creates a limit node that applies skip (start) and fetch (length) to inner.

pub fn order_by( self, exprs: &[Sort], ) -> Result<RdfFusionLogicalPlanBuilder, DataFusionError>

Sorts the current plan by a given set of expressions.

pub fn union( self, rhs: LogicalPlan, ) -> Result<RdfFusionLogicalPlanBuilder, DataFusionError>

Creates a union of the current plan and another plan.

pub fn minus( self, rhs: LogicalPlan, ) -> Result<RdfFusionLogicalPlanBuilder, DataFusionError>

Subtracts the results of another plan from the current plan.

pub fn group( self, variables: &[Variable], aggregates: &[(Variable, Expr)], ) -> Result<RdfFusionLogicalPlanBuilder, DataFusionError>

Groups the current plan by a set of variables and applies aggregate expressions.

pub fn distinct(self) -> Result<RdfFusionLogicalPlanBuilder, DataFusionError>

Removes duplicate solutions from the current plan.

pub fn distinct_with_sort( self, sorts: Vec<Sort>, ) -> Result<RdfFusionLogicalPlanBuilder, DataFusionError>

Removes duplicate solutions from the current plan, with additional sorting.

pub fn pattern( self, pattern: Vec<Option<TermPattern>>, ) -> Result<RdfFusionLogicalPlanBuilder, DataFusionError>

Removes duplicate solutions from the current plan.

pub fn with_plain_terms( self, ) -> Result<RdfFusionLogicalPlanBuilder, DataFusionError>

Ensures all columns are encoded as plain terms.

pub fn schema(&self) -> &Arc<DFSchema>

Returns the schema of the current plan.

pub fn context(&self) -> &RdfFusionLogicalPlanBuilderContext

Returns the builder context.

pub fn into_inner(self) -> LogicalPlanBuilder

Consumes the builder and returns the inner LogicalPlanBuilder.

pub fn build(self) -> Result<LogicalPlan, DataFusionError>

Builds the LogicalPlan.

pub fn expr_builder_root(&self) -> RdfFusionExprBuilderContext<'_>

Returns a new RdfFusionExprBuilderContext.

pub fn expr_builder( &self, expr: Expr, ) -> Result<RdfFusionExprBuilder<'_>, DataFusionError>

Returns a new RdfFusionExprBuilder for a given expression.

Trait Implementations

impl Clone for RdfFusionLogicalPlanBuilder

fn clone(&self) -> RdfFusionLogicalPlanBuilder

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RdfFusionLogicalPlanBuilder

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.