composer require flow-php/etl ~0.33.0 
Read from various data sources.
Shape and optimize for your needs.
Store and secure in one of many available data sinks.
Group rows based on column values, ensuring related records stay together in the same batch. This is useful when processing hierarchical data (like orders with line items) where splitting related records would cause integrity issues.
Important: Data must be sorted by the grouping column before using batch_by.
<?php
declare(strict_types=1);
use function Flow\ETL\DSL\{constraint_sorted_by, data_frame, from_array, ref, to_output};
require __DIR__ . '/vendor/autoload.php';
data_frame()
->read(from_array([
['order_id' => 1, 'item' => 'Widget', 'qty' => 2],
['order_id' => 1, 'item' => 'Gadget', 'qty' => 1],
['order_id' => 2, 'item' => 'Widget', 'qty' => 5],
['order_id' => 2, 'item' => 'Gizmo', 'qty' => 3],
['order_id' => 3, 'item' => 'Widget', 'qty' => 1],
]))
->constrain(constraint_sorted_by(ref('order_id')))
->batchBy('order_id')
->write(to_output(truncate: false))
->run();
