Struct AggregateExpr 

pub struct AggregateExpr {
    pub function: AggregateFunction,
    pub column: Option<usize>,
    pub distinct: bool,
    pub alias: Option<String>,
    pub percentile: Option<f64>,
}

An aggregation expression.

Fields

function: AggregateFunction

The aggregation function.

column: Option<usize>

Column index to aggregate (None for COUNT(*)).

distinct: bool

Whether to aggregate distinct values only.

alias: Option<String>

Output alias (for naming the result column).

percentile: Option<f64>

Percentile parameter for PERCENTILE_DISC/PERCENTILE_CONT (0.0 to 1.0).

Implementations

impl AggregateExpr

pub fn count_star() -> Self

Creates a COUNT(*) expression.

pub fn count(column: usize) -> Self

Creates a COUNT(column) expression.

pub fn sum(column: usize) -> Self

Creates a SUM(column) expression.

pub fn avg(column: usize) -> Self

Creates an AVG(column) expression.

pub fn min(column: usize) -> Self

Creates a MIN(column) expression.

pub fn max(column: usize) -> Self

Creates a MAX(column) expression.

pub fn first(column: usize) -> Self

Creates a FIRST(column) expression.

pub fn last(column: usize) -> Self

Creates a LAST(column) expression.

pub fn collect(column: usize) -> Self

Creates a COLLECT(column) expression.

pub fn stdev(column: usize) -> Self

Creates a STDEV(column) expression (sample standard deviation).

pub fn stdev_pop(column: usize) -> Self

Creates a STDEVP(column) expression (population standard deviation).

pub fn percentile_disc(column: usize, percentile: f64) -> Self

Creates a PERCENTILE_DISC(column, percentile) expression.

Arguments

• column - Column index to aggregate
• percentile - Percentile value between 0.0 and 1.0 (e.g., 0.5 for median)

pub fn percentile_cont(column: usize, percentile: f64) -> Self

Creates a PERCENTILE_CONT(column, percentile) expression.

Arguments

• column - Column index to aggregate
• percentile - Percentile value between 0.0 and 1.0 (e.g., 0.5 for median)

pub fn with_distinct(self) -> Self

Sets the distinct flag.

pub fn with_alias(self, alias: impl Into<String>) -> Self

Sets the output alias.

Trait Implementations

impl Clone for AggregateExpr

fn clone(&self) -> AggregateExpr

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for AggregateExpr

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

Formats the value using the given formatter.