nextcloud-gpodder/lib/Migration/TimestampMigration.php

<?php
declare(strict_types=1);

namespace OCA\GPodderSync\Migration;

use OCP\IDBConnection;
use OCP\Migration\IOutput;
use DateTime;

class TimestampMigration implements \OCP\Migration\IRepairStep
{
    private IDBConnection $db;

    public function __construct(IDBConnection $db)
    {
        $this->db = $db;
    }

    /**
     * @inheritDoc
     */
    public function getName(): string
    {
        return "Migrate timestamp values to integer to store unix epoch";
    }

    /**
     * @inheritDoc
     */
    public function run(IOutput $output)
    {
        $queryTimestamps =
            "SELECT id, timestamp FROM `*PREFIX*gpodder_episode_action` WHERE timestamp_epoch = 0";
        $timestamps = $this->db->executeQuery($queryTimestamps)->fetchAll();

        $result = 0;

        foreach ($timestamps as $timestamp) {
            $timestampEpoch = (new DateTime($timestamp["timestamp"]))->format(
                "U"
            );
            $sql =
                "UPDATE `*PREFIX*gpodder_episode_action` " .
                "SET `timestamp_epoch` = " .
                $timestampEpoch .
                " " .
                "WHERE `id` = " .
                $timestamp["id"];

            $result += $this->db->executeUpdate($sql);
        }

        return $result;
    }
}