sql分页

public DataSet GetAllUser(string sellnick, int pagesize, int pagecount, string sort, string order)
        {
            string orderby = "U.UserID asc";
            if (!string.IsNullOrEmpty(sort))
            {
               orderby = " " + sort + "  " + order + " ";               
            }
            int pagebegin = (pagesize - 1) * pagecount + 1;
            StringBuilder strSql = new StringBuilder();
            strSql.Append("select * from (select ROW_NUMBER() OVER(ORDER BY " + orderby + ") AS ID,U.UserNick,SellerNick,UserCredit,UserID,LastTradeTime,Rnum,Rprice,Phone,Vipinfo,R.UserType as UserType1  from [User] as U inner join Relation as R on U.UserNick=R.UserNick where SellerNick=@SellerNick) as temp where  ID between " + pagebegin + " and " + pagesize * pagecount + "");
            SqlParameter[] prams = { new SqlParameter("@SellerNick", SqlDbType.NVarChar, 50) };
            prams[0].Value = sellnick;
            DataSet ds = SqlHelper.ExcuteSelectReturnDataSet(strSql.ToString(), CommandType.Text, prams);
            return ds;
        }