Contao\Database\Updater::run32Update PHP Method

    public function run32Update()
    {
        // Adjust the custom layout sections (see #2885)
        $this->Database->query("ALTER TABLE `tl_layout` CHANGE `sections` `sections` varchar(1022) NOT NULL default ''");
        $objLayout = $this->Database->query("SELECT id, sections FROM tl_layout WHERE sections!=''");
        while ($objLayout->next()) {
            $strSections = '';
            $tmp = \StringUtil::deserialize($objLayout->sections);
            if (!empty($tmp) && is_array($tmp)) {
                $strSections = implode(', ', $tmp);
            }
            $this->Database->prepare("UPDATE tl_layout SET sections=? WHERE id=?")->execute($strSections, $objLayout->id);
        }
        // Check whether there are UUIDs
        if (!$this->Database->fieldExists('uuid', 'tl_files')) {
            // Adjust the DB structure
            $this->Database->query("ALTER TABLE `tl_files` ADD `uuid` binary(16) NULL");
            $this->Database->query("ALTER TABLE `tl_files` ADD UNIQUE KEY `uuid` (`uuid`)");
            // Backup the pid column and change the column type
            $this->Database->query("ALTER TABLE `tl_files` ADD `pid_backup` int(10) unsigned NOT NULL default '0'");
            $this->Database->query("UPDATE `tl_files` SET `pid_backup`=`pid`");
            $this->Database->query("ALTER TABLE `tl_files` CHANGE `pid` `pid` binary(16) NULL");
            $this->Database->query("UPDATE `tl_files` SET `pid`=NULL");
            $this->Database->query("UPDATE `tl_files` SET `pid`=NULL WHERE `pid_backup`=0");
            $objFiles = $this->Database->query("SELECT id FROM tl_files");
            // Generate the UUIDs
            while ($objFiles->next()) {
                $this->Database->prepare("UPDATE tl_files SET uuid=? WHERE id=?")->execute($this->Database->getUuid(), $objFiles->id);
            }
            $objFiles = $this->Database->query("SELECT pid_backup FROM tl_files WHERE pid_backup>0 GROUP BY pid_backup");
            // Adjust the parent IDs
            while ($objFiles->next()) {
                $objParent = $this->Database->prepare("SELECT uuid FROM tl_files WHERE id=?")->execute($objFiles->pid_backup);
                if ($objParent->numRows < 1) {
                    throw new \Exception('Invalid parent ID ' . $objFiles->pid_backup);
                }
                $this->Database->prepare("UPDATE tl_files SET pid=? WHERE pid_backup=?")->execute($objParent->uuid, $objFiles->pid_backup);
            }
            // Drop the pid_backup column
            $this->Database->query("ALTER TABLE `tl_files` DROP `pid_backup`");
        }
        // Update the fields
        $this->updateFileTreeFields();
    }