Struct Unique 

pub struct Unique { /* private fields */ }

A transform that removes duplicate rows based on specified columns.

Example

use alimentar::Unique;

// Keep only unique rows based on all columns
let unique = Unique::all();

// Keep only unique rows based on specific columns
let unique = Unique::by(vec!["user_id", "date"]);

// Keep first occurrence (default) or last
let unique = Unique::by(vec!["id"]).keep_first();
let unique = Unique::by(vec!["id"]).keep_last();

Implementations

impl Unique

pub fn all() -> Self

Creates a Unique transform that considers all columns.

pub fn by<S: Into<String>>(columns: impl IntoIterator<Item = S>) -> Self

Creates a Unique transform that considers specific columns.

pub fn keep_first(self) -> Self

Keep the first occurrence of duplicates (default).

pub fn keep_last(self) -> Self

Keep the last occurrence of duplicates.

pub fn columns(&self) -> Option<&[String]>

Returns the columns used for uniqueness check.

Trait Implementations

impl Clone for Unique

fn clone(&self) -> Unique

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Unique

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

Formats the value using the given formatter.

impl Transform for Unique

fn apply(&self, batch: RecordBatch) -> Result<RecordBatch>

Applies the transform to a RecordBatch.