linq实际应用代码

    #region 获取新闻列表信息 getNewsInfoList
    /// <summary>
    /// getNewsInfoList
    /// </summary>
    /// <param name="infoVer"></param>
    /// <param name="title"></param>
    /// <param name="classID"></param>
    /// <param name="curpage"></param>
    /// <param name="pagesize"></param>
    /// <param name="records"></param>
    /// <returns></returns>
    public static List<News_Class_View> getNewsInfoList(int infoVer, string title, int classID, int curpage, int pagesize, out int records)
    {
        using (SiteCMSDataContext db = new SiteCMSDataContext())
        {
            records = (from temp in db.News_Class_View
                       where temp.InfoVer == infoVer
                       && ((classID == 0) || (temp.ClassID == classID))
                       && SqlMethods.Like(temp.Title, "%" + title + "%")
                       select temp.NewsID).Count();

            int takes = curpage * pagesize;
            int skips = (curpage - 1) * pagesize;

            var query = (from temp in db.News_Class_View
                         where temp.InfoVer == infoVer
                         && ((classID == 0) || (temp.ClassID == classID))
                         && SqlMethods.Like(temp.Title, "%" + title + "%")
                         orderby temp.IsTop descending, temp.NewsDate descending, temp.CreateDate descending
                         select new News_Class_View
                         {
                             NewsID = temp.NewsID,
                             Title = temp.Title,
                             Source = temp.Source,
                             Author = temp.Author,
                             ClassName = temp.ClassName,
                             NewsDate = temp.NewsDate,
                             ViewNum = temp.ViewNum,
                             Summary = temp.Summary
                         }
                       ).Take(takes).Skip(skips);
            
            return query.ToList();
        }
    }
    #endregion

    #region 添加新闻信息 addNewsInfo
    /// <summary>
    /// 添加新闻信息
    /// </summary>
    /// <param name="entity"></param>
    public static void addNewsInfo(NewsInfo entity)
    {
        using (SiteCMSDataContext db = new SiteCMSDataContext())
        {
            db.NewsInfo.InsertOnSubmit(entity);
            db.SubmitChanges();
        }
    }
    #endregion

    #region 更新新闻信息 updateNewsInfo
    /// <summary>
    /// 更新新闻信息
    /// </summary>
    /// <param name="entity"></param>
    public static void updateNewsInfo(NewsInfo entity)
    {
        using (SiteCMSDataContext db = new SiteCMSDataContext())
        {
            var temp = db.NewsInfo.Where(w => w.NewsID == entity.NewsID).SingleOrDefault();
            if (temp != null)
            {
                temp.Title = entity.Title;
                temp.SubTitle=entity.SubTitle;
                temp.Source = entity.Source;
                temp.Author = entity.Author;
                temp.ClassID = entity.ClassID;
                temp.Summary = entity.Summary;
                temp.NewsDate = entity.NewsDate;
                temp.ImgUrl = entity.ImgUrl;
                temp.IsTop = entity.IsTop;
                temp.Content = entity.Content;

                db.SubmitChanges();
            }
        }
    }
    #endregion

    #region 删除新闻信息 deleteNewsInfo
    /// <summary>
    /// 删除新闻信息
    /// </summary>
    /// <param name="newsID"></param>
    public static void deleteNewsInfo(int newsID)
    {
        using (SiteCMSDataContext db = new SiteCMSDataContext())
        {
            var temp = db.NewsInfo.Where(w => w.NewsID == newsID).SingleOrDefault();
            if (temp != null)
            {
                db.NewsInfo.DeleteOnSubmit(temp);
                db.SubmitChanges();
            }
        }
    }
    #endregion

    #region 批量删除新闻信息 deleteNewsInfo
    /// <summary>
    /// 批量删除新闻信息
    /// </summary>
    /// <param name="newsID"></param>
    public static void deleteNewsInfo(int[] newsID)
    {
        using (SiteCMSDataContext db = new SiteCMSDataContext())
        {
            var list = db.NewsInfo.Where(w => newsID.Contains(w.NewsID));
            db.NewsInfo.DeleteAllOnSubmit(list.ToList());
            db.SubmitChanges();
        }
    }
    #endregion

    #region 获取新闻详细信息 getNewsInfoDetail
    /// <summary>
    /// 获取新闻详细信息
    /// </summary>
    /// <param name="newsID"></param>
    /// <returns></returns>
    public static News_Class_View getNewsInfoDetail(int newsID)
    {
        using (SiteCMSDataContext db = new SiteCMSDataContext())
        {
            var temp = db.News_Class_View.Where(w => w.NewsID == newsID);
            return temp.SingleOrDefault();
        }
    }
    #endregion

    #region 获取图片新闻信息 getImageNewsInfo
    /// <summary>
    /// 获取图片新闻信息
    /// </summary>
    /// <param name="infoVer"></param>
    /// <param name="classID"></param>
    /// <param name="topNum"></param>
    /// <returns></returns>
    public static List<NewsInfo> getImageNewsInfo(int infoVer, int classID, int topNum)
    {
        using (SiteCMSDataContext db = new SiteCMSDataContext())
        {
            if (topNum == 0)
            {
                var query = from temp in db.NewsInfo
                            where temp.InfoVer == infoVer
                            && ((classID == 0) || (temp.ClassID == classID))
                            && temp.ImgUrl != ""
                            orderby temp.IsTop descending, temp.NewsDate descending
                            select temp;
                return query.ToList();
            }
            else
            {
                var query = (from temp in db.NewsInfo
                            where temp.InfoVer == infoVer
                            && ((classID == 0) || (temp.ClassID == classID))
                            && temp.ImgUrl != ""
                            orderby temp.IsTop descending, temp.NewsDate descending
                            select temp).Take(topNum);

                return query.ToList();
            }           
        }
    }
    #endregion

    #region 获取最新的Top新闻信息
    /// <summary>
    /// 获取最新的Top新闻信息
    /// </summary>
    /// <param name="infoVer"></param>
    /// <param name="classID"></param>
    /// <param name="topNum"></param>
    /// <returns></returns>
    public static List<NewsInfo> getTopNewsInfo(int infoVer, int classID, int topNum)
    {
        using (SiteCMSDataContext db = new SiteCMSDataContext())
        { 
            var query=(from temp in db.NewsInfo
                      where temp.InfoVer==infoVer
                      &&((classID==0) || (temp.ClassID==classID))
                      orderby temp.IsTop descending,temp.NewsDate descending
                      select temp).Take(topNum);

            return query.ToList();
        }
    }
    #endregion