Get Total by Reference

function mycred_total_per_ref( $ref = '', $user_id = NULL )
{
    // Reference is required
    if ( empty( $ref ) ) return false;

    global $wpdb;

    // The myCRED Log
    $db = $wpdb->prefix . 'myCRED_log';

    // Get myCRED
    $mycred = mycred_get_settings();

    // Get all points given for this reference to a specific user
    if ( $user_id !== NULL ) {
        $sql = "SELECT creds FROM {$db} WHERE ref = %s AND user_id = %d";
        $query = $wpdb->get_results( $wpdb->prepare( $sql, $ref, $user_id ) );
    }
    // Get all points given for this reference
    else {
        $sql = "SELECT creds FROM {$db} WHERE ref = %s";
        $query = $wpdb->get_results( $wpdb->prepare( $sql, $ref ) );
    }

    $count = 0;
    // if we have results we add creds up
    if ( !empty( $query ) ) {
        foreach ( $query as $entry ) {
            $count = $count+$entry->creds;
        }
    }

    return $mycred->number( $count );
}