Typo3DbQueryParseWithOrderByField.php

<?php
namespace Vendor\Extension\Storage;

use TYPO3\CMS\Extbase\Persistence\Generic\Qom\SourceInterface;
use TYPO3\CMS\Extbase\Persistence\Generic\Storage\Typo3DbQueryParser;

/**
 * This class allows ordering by 'FIELD' SQL statement.
 *
 * @author Dmitry Dulepov <dmitry.dulepov@gmail.com>
 * @see https://dev.mysql.com/doc/refman/8.0/en/string-functions.html#function_field
 */
class Typo3DbQueryParseWithOrderByField extends Typo3DbQueryParser
{
    /**
     * Adds FIELD sorting support to the query.
     *
     * @param array $orderings
     * @param \TYPO3\CMS\Extbase\Persistence\Generic\Qom\SourceInterface $source
     * @throws \TYPO3\CMS\Extbase\Persistence\Generic\Exception\UnsupportedOrderException
     */
    protected function parseOrderings(array $orderings, SourceInterface $source)
    {
        foreach ($orderings as $propertyName => $order) {
            if (preg_match('/^\s*field\s*\(/i', $propertyName)) {
                $this->queryBuilder->getConcreteQueryBuilder()->addOrderBy($propertyName, $order);
            } else {
                parent::parseOrderings([$propertyName => $order], $source);
            }
        }
    }
}