<?php declare(strict_types=1); use function Flow\ETL\DSL\{data_frame, from_rows, int_entry, lit, ref, row, rows, to_stream, when}; require __DIR__ . '/../../../autoload.php'; data_frame() ->read(from_rows(rows( row(int_entry('id', 1), int_entry('value', 1)), row(int_entry('id', 2), int_entry('value', 1)), row(int_entry('id', 3), int_entry('value', null)), row(int_entry('id', 4), int_entry('value', 1)), row(int_entry('id', 5), int_entry('value', null)), ))) ->withEntry( 'value', when(ref('value')->isNull(), then: lit(0)) ) ->write(to_stream(__DIR__ . '/output.txt', truncate: false)) ->run();
+----+-------+ | id | value | +----+-------+ | 1 | | | 2 | | | 3 | 0 | | 4 | | | 5 | 0 | +----+-------+ 5 rows