Linq To EF简单的增、删、查、改

新增

            //新增
            T_Teacher tt1 = new T_Teacher()
            {
                Name = "路人丁",
                Address = "宰相府55栋",
                Phone = "13725256545",
                Email = "[email protected]",
                ClassID = 1
            };
            sdb.T_Teacher.AddObject(tt1);
            int result = sdb.SaveChanges();

删除

            //删除
            var ttlist = from cc in sdb.T_Teacher where cc.ID == 3 select cc;
            foreach (var item in ttlist)
            {
                sdb.T_Teacher.DeleteObject(item);
            }
            int result = sdb.SaveChanges();

查询

            //查询
            var ttlist = from cc in sdb.T_Teacher select cc;
            string result = "";
            foreach (var item in ttlist)
            {
                result += item.Name + "*******";
            }

修改

            //修改
            var ttlist = from cc in sdb.T_Teacher select cc;
            var wokao = ttlist.FirstOrDefault<T_Teacher>();
            int result = 0;
            if (wokao != null)
            {
                wokao.Name = "123";
                result = sdb.SaveChanges();
            }
            else
            {
                result = 0;
            }