Enum WindowFunction 

pub enum WindowFunction {
    RowNumber,
    Rank,
    DenseRank,
    Lag {
        column: ColumnName,
        offset: usize,
    },
    Lead {
        column: ColumnName,
        offset: usize,
    },
    FirstValue {
        column: ColumnName,
    },
    LastValue {
        column: ColumnName,
    },
}

Window function operations supported by the engine.

ROW_NUMBER / RANK / DENSE_RANK are pure ranking functions (no args). LAG / LEAD look at a sibling row offset (default 1). FIRST_VALUE / LAST_VALUE return the column at the partition boundary.

Variants

RowNumber

Rank

DenseRank

Lag

LAG(column, offset = 1) — value offset rows back, NULL if before partition start.

Fields

column: ColumnName

offset: usize

Lead

LEAD(column, offset = 1) — value offset rows forward, NULL if past partition end.

Fields

column: ColumnName

offset: usize

FirstValue

FIRST_VALUE(column) — value of column at the first row of the current partition (under the ORDER BY).

Fields

column: ColumnName

LastValue

LAST_VALUE(column) — value of column at the last row of the current partition. Per ANSI default frame, “last row” here means the current row — so we treat LAST_VALUE with no explicit frame as “value of column on the current row”. Postgres parity in tests/.

Fields

column: ColumnName

Implementations

impl WindowFunction

pub fn default_alias(&self) -> &'static str

Output column name when no alias is present.

Trait Implementations

impl Clone for WindowFunction

fn clone(&self) -> WindowFunction

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for WindowFunction

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

Formats the value using the given formatter.

impl PartialEq for WindowFunction

fn eq(&self, other: &WindowFunction) -> 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 Eq for WindowFunction

impl StructuralPartialEq for WindowFunction