Enum WindowFunc 

#[non_exhaustive]
pub enum WindowFunc {
    RowNumber,
    Rank,
    DenseRank,
    Lag {
        expr: Box<Expr>,
        offset: usize,
    },
    Lead {
        expr: Box<Expr>,
        offset: usize,
    },
    FirstValue {
        expr: Box<Expr>,
    },
    LastValue {
        expr: Box<Expr>,
    },
    Aggregate {
        func: AggregateFunc,
        expr: Box<Expr>,
    },
}

윈도우 함수 종류

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

RowNumber

row_number() — 행 번호 (1부터 시작)

Rank

rank() — 순위 (동점 시 같은 순위, 다음 순위 건너뜀)

DenseRank

dense_rank() — 순위 (동점 시 같은 순위, 다음 순위 연속)

Lag

lag(expr, offset) — 이전 행 값 참조

Fields

expr: Box<Expr>

offset: usize

Lead

lead(expr, offset) — 다음 행 값 참조

Fields

expr: Box<Expr>

offset: usize

FirstValue

first_value(expr) — 윈도우 내 첫 번째 값

Fields

expr: Box<Expr>

LastValue

last_value(expr) — 윈도우 내 마지막 값

Fields

expr: Box<Expr>

Aggregate

윈도우 집계: sum(expr) over (...)

Fields

func: AggregateFunc

expr: Box<Expr>

Trait Implementations

impl Clone for WindowFunc

fn clone(&self) -> WindowFunc

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for WindowFunc

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

Formats the value using the given formatter.

impl PartialEq for WindowFunc

fn eq(&self, other: &WindowFunc) -> 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 WindowFunc