Struct CountAccumulator 

pub struct CountAccumulator { /* private fields */ }

Accumulator for COUNT / COUNT(DISTINCT).

Implementations

impl CountAccumulator

pub fn new(distinct: bool) -> Self

Create a new count accumulator.

Trait Implementations

impl Accumulator for CountAccumulator

fn update(&mut self, value: Option<SqlValue>) -> Result<()>

Update the accumulator with a new value (None for COUNT(*) rows).

fn finalize(&self) -> Result<SqlValue>

Finalize the accumulator and return the resulting SqlValue.

fn state(&self) -> Result<Vec<SqlValue>>

Return the serializable partial aggregate state.

fn merge(&mut self, state: &[SqlValue]) -> Result<()>

Merge a partial state produced by an accumulator of the same function.

fn clone_box(&self) -> Box<dyn Accumulator>

Clone the accumulator as a trait object.

impl Clone for CountAccumulator

fn clone(&self) -> CountAccumulator

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CountAccumulator

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

Formats the value using the given formatter.