public Collect <Hashtable> page(int pagesize)
        {
            Db c = new Db(getName());

            HashtableUtil.extend(true, c.mOption, mOption);

            // 总长度
            long count = c.count();
            Collect <Hashtable> result = new Collect <Hashtable>(count, pagesize);

            this.limit(result.firstRow, result.listRows);
            builder.setPage(true);
            selectCollect(result);
            builder.setPage(false);
            return(result);
        }