Struct QueryBuilder 

pub struct QueryBuilder<'outer, 'a> { /* private fields */ }

Builder for the “query” portion of the rule.

Queries specify scans or joins over the database that bind variables that are accessible to rules.

Implementations

impl<'outer, 'a> QueryBuilder<'outer, 'a>

pub fn build(self) -> RuleBuilder<'outer, 'a>

Finish the query and start building the right-hand side of the rule.

pub fn set_plan_strategy(&mut self, strategy: PlanStrategy)

Set the target plan strategy to use to execute this query.

pub fn new_var(&mut self) -> Variable

Create a new variable of the given type.

pub fn add_atom<'b>( &mut self, table_id: TableId, vars: &[QueryEntry], cs: impl IntoIterator<Item = &'b Constraint>, ) -> Result<AtomId, QueryError>

Add the given atom to the query, with the given variables and constraints.

NB: it is possible to constrain two non-equal variables to be equal given this setup. Doing this will not cause any problems but nevertheless is not recommended.

The returned AtomId can be used to refer to this atom when adding constraints in [RuleSetBuilder::rule_from_cached_plan].

Panics

Like most methods that take a TableId, this method will panic if the given table is not declared in the corresponding database.