Enum WindowFunctionSpec 

pub enum WindowFunctionSpec {
    Aggregate {
        name: FunctionIdentifier,
        args: Vec<Expression>,
        filter: Option<Box<Expression>>,
    },
    Ranking {
        name: FunctionIdentifier,
        args: Vec<Expression>,
    },
    Value {
        name: FunctionIdentifier,
        args: Vec<Expression>,
    },
}

Window function specification

Uses FunctionIdentifier for proper case handling in all variants. SQL:2003 FILTER clause is supported for conditional aggregation within windows.

Variants

Aggregate

Aggregate function used as window function Example: SUM(salary), AVG(price), COUNT() Example with FILTER: COUNT() FILTER (WHERE x > 0) OVER (PARTITION BY y)

Fields

name: FunctionIdentifier

args: Vec<Expression>

filter: Option<Box<Expression>>

Optional FILTER clause for conditional aggregation

Ranking

Ranking function Example: ROW_NUMBER(), RANK(), DENSE_RANK(), NTILE(4)

Fields

name: FunctionIdentifier

args: Vec<Expression>

Value

Value function Example: LAG(salary, 1), LEAD(price, 2), FIRST_VALUE(name), LAST_VALUE(amount)

Fields

name: FunctionIdentifier

args: Vec<Expression>

Implementations

impl WindowFunctionSpec

pub fn name(&self) -> String

Get the function name from any window function variant

Trait Implementations

impl Clone for WindowFunctionSpec

fn clone(&self) -> WindowFunctionSpec

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for WindowFunctionSpec

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

Formats the value using the given formatter.

impl PartialEq for WindowFunctionSpec

fn eq(&self, other: &WindowFunctionSpec) -> 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 ToSql for WindowFunctionSpec

fn to_sql(&self) -> String

Convert this AST node to a SQL string

impl StructuralPartialEq for WindowFunctionSpec