Method aggregate

datafusion/expr/src/logical_plan/builder.rs:1286–1303

Apply an aggregate: grouping on the `group_expr` expressions and calculating `aggr_expr` aggregates for each distinct value of the `group_expr`;

(
        self,
        group_expr: impl IntoIterator<Item = impl Into<Expr>>,
        aggr_expr: impl IntoIterator<Item = impl Into<Expr>>,
    )

    /// and calculating `aggr_expr` aggregates for each distinct
    /// value of the `group_expr`;
    pub fn aggregate(
        self,
        group_expr: impl IntoIterator<Item = impl Into<Expr>>,
        aggr_expr: impl IntoIterator<Item = impl Into<Expr>>,
    ) -> Result<Self> {
        let group_expr = normalize_cols(group_expr, &self.plan)?;
        let aggr_expr = normalize_cols(aggr_expr, &self.plan)?;

        let group_expr = if self.options.add_implicit_group_by_exprs {
            add_group_by_exprs_from_dependencies(group_expr, self.plan.schema())?
        } else {
            group_expr
        };

        Aggregate::try_new(self.plan, group_expr, aggr_expr)
            .map(LogicalPlan::Aggregate)
            .map(Self::new)
    }

    /// Create an expression to represent the explanation of the plan
    ///