Struct arrow::record_batch::RecordBatch

pub struct RecordBatch { /* fields omitted */ }

A two-dimensional batch of column-oriented data with a defined schema.

A RecordBatch is a two-dimensional dataset of a number of contiguous arrays, each the same length. A record batch has a schema which must match its arrays’ datatypes.

Record batches are a convenient unit of work for various serialization and computation functions, possibly incremental. See also CSV reader and JSON reader.

Implementations

impl RecordBatch

pub fn try_new(schema: SchemaRef, columns: Vec<ArrayRef>) -> Result<Self>

Creates a RecordBatch from a schema and columns.

Expects the following:

• the vec of columns to not be empty
• the schema and column data types to have equal lengths and match
• each array in columns to have the same length

If the conditions are not met, an error is returned.

Example

use std::sync::Arc;
use arrow::array::Int32Array;
use arrow::datatypes::{Schema, Field, DataType};
use arrow::record_batch::RecordBatch;

let id_array = Int32Array::from(vec![1, 2, 3, 4, 5]);
let schema = Schema::new(vec![
    Field::new("id", DataType::Int32, false)
]);

let batch = RecordBatch::try_new(
    Arc::new(schema),
    vec![Arc::new(id_array)]
)?;

pub fn try_new_with_options(
    schema: SchemaRef,
    columns: Vec<ArrayRef>,
    options: &RecordBatchOptions
) -> Result<Self>

Creates a RecordBatch from a schema and columns, with additional options, such as whether to strictly validate field names.

See RecordBatch::try_new for the expected conditions.

pub fn schema(&self) -> SchemaRef

Returns the Schema of the record batch.

pub fn num_columns(&self) -> usize

Returns the number of columns in the record batch.

Example

use std::sync::Arc;
use arrow::array::Int32Array;
use arrow::datatypes::{Schema, Field, DataType};
use arrow::record_batch::RecordBatch;

let id_array = Int32Array::from(vec![1, 2, 3, 4, 5]);
let schema = Schema::new(vec![
    Field::new("id", DataType::Int32, false)
]);

let batch = RecordBatch::try_new(Arc::new(schema), vec![Arc::new(id_array)])?;

assert_eq!(batch.num_columns(), 1);

pub fn num_rows(&self) -> usize

Returns the number of rows in each column.

Panics

Panics if the RecordBatch contains no columns.

Example

use std::sync::Arc;
use arrow::array::Int32Array;
use arrow::datatypes::{Schema, Field, DataType};
use arrow::record_batch::RecordBatch;

let id_array = Int32Array::from(vec![1, 2, 3, 4, 5]);
let schema = Schema::new(vec![
    Field::new("id", DataType::Int32, false)
]);

let batch = RecordBatch::try_new(Arc::new(schema), vec![Arc::new(id_array)])?;

assert_eq!(batch.num_rows(), 5);

pub fn column(&self, index: usize) -> &ArrayRef

Get a reference to a column's array by index.

Panics

Panics if index is outside of 0..num_columns.

pub fn columns(&self) -> &[ArrayRef]

Get a reference to all columns in the record batch.

Trait Implementations

impl Clone for RecordBatch

fn clone(&self) -> RecordBatch

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for RecordBatch

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

Formats the value using the given formatter.

impl From<&'_ StructArray> for RecordBatch

fn from(struct_array: &StructArray) -> Self

Create a record batch from struct array.

This currently does not flatten and nested struct types

impl Into<StructArray> for RecordBatch

fn into(self) -> StructArray

Performs the conversion.