在oracle中得到分页数据

在oracle中得到分页数据 得到DataSet的值
例子如下：
/// <summary>
/// 得到Colletion分页数据
/// </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;
}
通过rownum <=(PageIndex-1)*PageSize 来选择取第几页，通过(PageIndex - 1) * PageSize + PageSize)来选择取该页的前几条。