Enum AggregateSource 

pub enum AggregateSource {
    Column(usize),
    Expression(Expression),
    CountStar,
}

Source of data for an aggregate - either a simple column or an expression

Variants

Column(usize)

Simple column reference (fast path) - just a column index

Expression(Expression)

Complex expression that needs evaluation (e.g., a * b)

CountStar

COUNT(*) - count all rows (not tied to any specific column)

Trait Implementations

impl Clone for AggregateSource

fn clone(&self) -> AggregateSource

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for AggregateSource

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

Formats the value using the given formatter.