Method flat_map

src/expr/src/relation.rs:1197–1203

Like `map`, but yields zero-or-more output rows per input row

(self, func: TableFunc, exprs: Vec<MirScalarExpr>)

    /// Like `map`, but yields zero-or-more output rows per input row
    pub fn flat_map(self, func: TableFunc, exprs: Vec<MirScalarExpr>) -> Self {
        MirRelationExpr::FlatMap {
            input: Box::new(self),
            func,
            exprs,
        }
    }

    /// Retain only the rows satisfying each of several predicates.
    pub fn filter<I>(mut self, predicates: I) -> Self