How can I delete all my existing trackbacks?

Question

I'm sorting out a long-neglected wordpress.org blog. It has over 100,000 pieces of trackback spam. How can I remove them all?

Answer 1

To make this more WP-ish:

function wpse_delete_trackbacks()
{
    global $wpdb;

    $wpdb->query( $wpdb->prepare(
        "
            DELETE FROM %s WHERE `comment_type` = 'trackback'
        ",
        "{$wpdb->prefix}comments"
    ) );
}

Answer 2

I gave up on finding an elegant solution and just used a MySQL sledgehammer to banish the spam:

DELETE FROM `wp_comments` WHERE `comment_type`="trackback"