EF增删改查操作

增

using (StudentEntities ent = new StudentEntities())
                    {
                        User aNewUser = new User()
                        {
                            Age = 20,
                            Name = strName,
                            Sex = strSex
                        };
                        ent.User.Add(aNewUser);
                        if (ent.SaveChanges() > 0)
                        {
                            Response.Write("添加成功。");
                        }
                        else
                        {
                            Response.Write("添加失败。");
                        }
                        Response.End();
                    }

删

 using (StudentEntities ent = new StudentEntities())
                    {
                        User aUser = (from c in ent.User where c.ID == iID select c).FirstOrDefault();
                        if (aUser != null)
                        {

                            ent.User.Remove(aUser);
                            if (ent.SaveChanges() > 0)
                            {
                                Response.Write("删除成功。");
                            }
                            else
                            {
                                Response.Write("删除失败。");
                            }
                        }
                        else
                        {
                            Response.Write("不存在此用户，请确认用户ID是否正确。");
                        }
                        Response.End();
                    }

改查

using (StudentEntities ent = new StudentEntities())
            {
                User aUser = (from c in ent.User where c.ID == iID select c).FirstOrDefault();
                if (aUser != null)
                {
                    aUser.Name = strName;
                    aUser.Age = 20;
                    aUser.Sex = strSex;
                    if (ent.SaveChanges() > 0)
                    {
                        Response.Write("<script>alert('修改成功。')</script>");
                    }
                }
            }