View file database/upgrades/20200125022205_resize_avatars_in_users.php

<?php

use Intervention\Image\ImageManagerStatic as Image;
use Phinx\Migration\AbstractMigration;

class ResizeAvatarsInUsers extends AbstractMigration
{
    /**
     * Migrate Up.
     */
    public function up(): void
    {
        $rows = $this->fetchAll('SELECT id, avatar, picture FROM users');

        foreach ($rows as $row) {
            $avatar = HOME . $row['avatar'];
            $picture = HOME . $row['picture'];

            if (! $row['picture'] || ! file_exists($picture)) {
                continue;
            }

            deleteFile($avatar);

            try {
                $img = Image::make($picture);
                $img->fit(64);
                $img->save($avatar);
            } catch (Exception $e) {
                // nothing
            }
        }
    }

    /**
     * Migrate Down.
     */
    public function down(): void
    {

    }
}