public static function &db($pdo = null)
    {
        $shared = self::instanced();
        if (is_object($pdo)) {
            $shared->dbLink = &$pdo;
        }
        if (!is_object($shared->dbLink)) {
            $shared->dbLink = self::db(SQL\PDO::singleton(is_array($pdo) ? $pdo : [
                ]));
        }

        return $shared->dbLink;
    }
public static function &db($pdo = null)
    {
        $shared = self::instanced();
        if (is_object($pdo)) {
            $shared->dbLink = &$pdo;
        }
        if (!is_object($shared->dbLink)) {
            $shared->dbLink = self::db(SQL\PDO::singleton(is_array($pdo) ? $pdo : [
                ]));
        }

        return $shared->dbLink;
    }
public static function & db ( $ pdo = null ) { $ shared = self :: instanced ( ) ; if ( is_object ( $ pdo ) ) { $ shared -> dbLink = & $ pdo ; } if ( ! is_object ( $ shared -> dbLink ) ) { $ shared -> dbLink = self :: db ( SQL \ PDO :: singleton ( is_array ( $ pdo ) ? $ pdo : [ ] ) ) ; } return $ shared -> dbLink ; }
Returns database object instance.

@return SQL\PDO
Returns database object instance .