在Oracle中得到分頁資料

在Oracle中得到分頁資料 得到DataSet的值
例子如下：
       /// <summary>
        /// 得到Colletion分頁資料
        /// </summary>
        public DataSet GetList(int PageIndex, int PageSize, string sortExpression, string strWhere)
        {
            StringBuilder sb = new StringBuilder();
            sb.Append("select * ");
            sb.Append(" from (select COLLECTGOODSID,PURCHASENUM,COLLECTIONTAG,MEMBERID,                    T_WEB_GOODS.*  from T_WEB_GOODS,T_WEB_COLLECTGOODS where T_WEB_GOODS.GOODID =                    T_WEB_COLLECTGOODS.GOODSID and  ");
            sb.Append(strWhere);
            sb.Append(" )temp");
            sb.Append(" where rownum>" + (PageIndex - 1) * PageSize + " and rownum <= " +                    ((PageIndex - 1) * PageSize + PageSize));
            DataSet ds = DbHelperOra.Query(sb.ToString());
            return ds;
        }
通過rownum <=(PageIndex-1)*PageSize 來選擇取第幾頁，通過(PageIndex - 1) * PageSize + PageSize)來選擇取該頁的前幾條。