linq增删改查的语法介绍

1、linq语法应用的很多。下面我将linq增删改查的语法介绍给大家，供大家学习和参考。1.查询语法(分为查询列表和条件查询)A. 查询列表public IQueryable getListl nfo() HotelDataClasses hoteldata=new HotelDataClasses ();IQueryable fianinfo = from h inhoteldata.Htel_ Finan cialPayeeselect new Htel_ Fin acialPayeeModelFp_ID = h.Fp_ID,Fp_PayeeBa nk = h.Fp_PayeeBa nk;if

2、 (fianin fo.Cou nt() 0)retur n fianinfo;else return nu II;B. 条件查询，返回MOdel数据集/编辑信息时通过编号查询到的酒店财务收款列表信息public Htel_ Finan cialPayee GetHtel Fin acialI nfosByid(l ong id)using (HotelDataClasses hotelData = new HotelDataClasses()var info = hotelData.Htel_Fi nan cialPayee.Where(P = P.Fp_ID = id).First();r

3、eturn info;c.多表联合查询语法有2个表的：IQueryableHtel_ Fin acialPayeeModelin folist = from h in hoteldata.Htel_ Finan cialPayee join compa ny in hoteldata.BasCompa nylnfo on h.Fp_Compa nyld equals compa ny.lD into Cwhere h.Fp_Compa nyld = Con vert.To In t32(comp nanyid )select new Htel_ Fin acialPayeeModelFp_ID

4、 = h.Fp_ID,Compa nyn ame = C.First().Compa ny Name,Fp_Payee = h.Fp_Payee,Fp_PayeeCard = h.Fp_PayeeCard,Fp_PayeeBa nk = h.Fp_PayeeBa nk;return in folist;3个以上的表联合查询IQueryableP.OrderCode=OrderCode)join dic in db.Htel_Dictio nary on in f.Cha nn elID equals dic.ID into lfrom y in I.DefaultlfEmpty()from h

5、 in db.Htel_Hotelfrom cn in db.Htel_HotelENfrom en in db.Htel_HotelCNfrom ddic in db.Htel_Dictio narywhere in f.MemberlD = memberidwhere inf.H otelID = h.IDwhere inf.H otelID = cn .HotelIDwhere in f.HotelID = en .HotelIDwhere in f.Payme ntID = ddicDselect new Reservati on DetailsArrivalTime = in f.A

6、rrivalTime,Cha nn elID = in f.Cha nn elID,Cha nn elName = y.NameCN,Check In = in f.Check in.Checkout = in f.Checkout,Compa nylD = in f.Compa ny ID,2. 修改语法public bool Update in fo(Htel_ Finan cialPayee model)HotelDataClasses hoteldata = new HotelDataClasses();var info = hoteldata.Htel_Fi nan cialPaye

7、e.Where(p = p.Fp_ID = model.Fp_ID); if (in fo.Cou nt() 0)Htel_Fi nan cialPayee inf = in fo.First();in f.Fp_ID = model.Fp_ID;in f.Fp_Payee = model.Fp_Payee;in f.Fp_PayeeCard = model.Fp_PayeeCard;hoteldata.SubmitCha nges();return true;elsereturn false;3. 删除语法public bool delI nfo(stri ng id) HotelDataC

8、lasses hoteldata = new HotelDataClasses();var info = hoteldata.Htel_Fi nan cialPayee.Where(p = p.Fp_ID = Convert.ToInt32(id ).First ();hoteldata.Htel_Fi nan cialPayee.Delete On Submit(i nfo);hoteldata.SubmitCha nges();return true;4.增加语法public bool Add in fo(Htel_ Finan cialPayee model) HotelDataClasses hoteldata = new HotelDataClasses();Htel_ Finan cialPayee fin amodel = new Htel_ Finan cialPayee();fin amodel.Fp_Payee = model.Fp_Payee;fin amodel.Fp_P