Struct Window 

pub struct Window {
    pub based_on: Option<Cow<'static, str>>,
    pub partition_by: Vec<Expr>,
    pub order_by: OrderBy,
    pub frame: Frame,
}

A window definition: what goes inside OVER (…), or after WINDOW name AS.

From PostgreSQL 17, https://www.postgresql.org/docs/17/sql-select.html#SQL-WINDOW:

[ existing_window_name ] [ PARTITION BY expression [, ...] ]
[ ORDER BY expression [ASC | DESC | USING operator] [NULLS {FIRST|LAST}] [, ...] ]
[ frame_clause ]

Every part is optional, including all of them at once: OVER () and WINDOW w AS () are both legal and mean “the whole partition”. So an empty Window renders the empty string and the parentheses come from whatever contains it.

Because it holds an OrderBy and a Frame and implements HasOrderBy and HasFrame, the ordinary order-by and frame mods apply to a window unchanged.

Fields

based_on: Option<Cow<'static, str>>

A window this one extends, copying its PARTITION BY and — unless this one has its own — its ORDER BY. Quoted on output.

partition_by: Vec<Expr>

PARTITION BY.

order_by: OrderBy

ORDER BY, which is what gives RANGE frames and rank() a meaning.

frame: Frame

The frame.

Implementations

impl Window

pub fn based_on(name: impl Into<Cow<'static, str>>) -> Self

A window extending an existing named one.

pub fn add_partition_by(&mut self, exprs: impl IntoExprList)

Append partition expressions.

pub fn is_empty(&self) -> bool

Whether nothing was set, so that OVER () is what will be written.

Trait Implementations

impl Clone for Window

fn clone(&self) -> Window

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Window

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

Formats the value using the given formatter.

impl Default for Window

fn default() -> Window

Returns the “default value” for a type.

impl Expression for Window

fn write_sql(&self, w: &mut SqlWriter<'_>)

Append this fragment to w.

impl HasFrame for Window

fn frame_mut(&mut self) -> &mut Frame

The frame to modify.

impl HasOrderBy for Window

fn order_by_mut(&mut self) -> &mut OrderBy

The ORDER BY clause to modify.

impl HasWindow for Window

fn window_mut(&mut self) -> &mut Window

The window definition to modify.