$DBversion = 'XXX';    # will be replaced by the RM

if ( CheckVersion($DBversion) ) {

    # you can use $dbh here like:

    $dbh->do(

"ALTER TABLE `article_requests` MODIFY `status` enum('REQUESTED', 'PENDING','PROCESSING','COMPLETED','CANCELED') COLLATE utf8mb4_unicode_ci NOT NULL DEFAULT 'REQUESTED'"

    );

    $dbh->do(

        q{

        UPDATE  `letter`

        SET     `code` = 'AR_REQUESTED',

                `name` = 'Article requested'

        WHERE   `module` = 'circulation'

                AND `code` = 'AR_PENDING'

    }

    );

    $dbh->do(

        q{

        INSERT IGNORE INTO `letter` (`module`, `code`, `branchcode`, `name`, `is_html`, `title`, `content`, `message_transport_type`) VALUES

        ('circulation', 'AR_PENDING', '', 'Article request - open', 0, 'Pending article request', 'Dear <<borrowers.firstname>> <<borrowers.surname>> (<<borrowers.cardnumber>>)\r\n\r\nYour request for an article from <<biblio.title>> (<<items.barcode>>) is now in pending state.\r\n\r\nArticle requested:\r\nTitle: <<article_requests.title>>\r\nAuthor: <<article_requests.author>>\r\nVolume: <<article_requests.volume>>\r\nIssue: <<article_requests.issue>>\r\nDate: <<article_requests.date>>\r\nPages: <<article_requests.pages>>\r\nChapters: <<article_requests.chapters>>\r\nNotes: <<article_requests.patron_notes>>\r\n\r\n\r\nThank you!', 'email')

    }

    );

    # Always end with this (adjust the bug info)

    NewVersion( $DBversion, 27944,

"Add REQUESTED as enum element for status column, move AR_PENDING letter to AR_REQUESTED, and add new AR_PENDING letter"

    );

}