Enum SubqueryKind 

pub enum SubqueryKind {
    InSubquery,
    NotInSubquery,
    Exists,
    NotExists,
    Scalar,
}

Classification of a subquery occurrence detected in a SQL statement.

Variants

InSubquery

expr IN (SELECT ...) — rewritten by DataFusion to a left-semi join.

NotInSubquery

expr NOT IN (SELECT ...) — rewritten to a left-anti join.

Exists

EXISTS (SELECT ...) — rewritten to a left-semi join.

NotExists

NOT EXISTS (SELECT ...) — rewritten to a left-anti join.

Scalar

(SELECT single_value) used as a scalar expression — rewritten to an apply/cross-join with a LIMIT 1 inner query.

Trait Implementations

impl Clone for SubqueryKind

fn clone(&self) -> SubqueryKind

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SubqueryKind

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

Formats the value using the given formatter.

impl Eq for SubqueryKind

impl PartialEq for SubqueryKind

fn eq(&self, other: &SubqueryKind) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for SubqueryKind