Struct datafusion_expr::window_frame::WindowFrame

pub struct WindowFrame {
    pub units: WindowFrameUnits,
    pub start_bound: WindowFrameBound,
    pub end_bound: WindowFrameBound,
    /* private fields */
}

The frame specification determines which output rows are read by an aggregate window function. The ending frame boundary can be omitted if the BETWEEN and AND keywords that surround the starting frame boundary are also omitted, in which case the ending frame boundary defaults to CURRENT ROW.

Fields

units: WindowFrameUnits

Frame type - either ROWS, RANGE or GROUPS

start_bound: WindowFrameBound

Starting frame boundary

end_bound: WindowFrameBound

Ending frame boundary

Implementations

impl WindowFrame

pub fn new(order_by: Option<bool>) -> Self

Creates a new, default window frame (with the meaning of default depending on whether the frame contains an ORDER BY clause and this ordering is strict (i.e. no ties).

pub fn reverse(&self) -> Self

Get reversed window frame. For example 3 ROWS PRECEDING AND 2 ROWS FOLLOWING –> 2 ROWS PRECEDING AND 3 ROWS FOLLOWING

pub fn is_causal(&self) -> bool

Get whether window frame is causal

pub fn new_bounds( units: WindowFrameUnits, start_bound: WindowFrameBound, end_bound: WindowFrameBound, ) -> Self

Initializes window frame from units (type), start bound and end bound.

pub fn regularize_order_bys(&self, order_by: &mut Vec<Expr>) -> Result<()>

Regularizes the ORDER BY clause of the window frame.

pub fn can_accept_multi_orderby(&self) -> bool

Returns whether the window frame can accept multiple ORDER BY expressons.

Trait Implementations

impl Clone for WindowFrame

fn clone(&self) -> WindowFrame

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for WindowFrame

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

Formats the value using the given formatter.

impl Display for WindowFrame

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

Formats the value using the given formatter.

impl Hash for WindowFrame

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for WindowFrame

fn eq(&self, other: &WindowFrame) -> 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 TryFrom<WindowFrame> for WindowFrame

type Error = DataFusionError

The type returned in the event of a conversion error.

fn try_from(value: WindowFrame) -> Result<Self>

Performs the conversion.

impl Eq for WindowFrame

impl StructuralPartialEq for WindowFrame