//当删除按钮点击的时候 protected void Button3_Click(object sender, EventArgs e) { var db = new myTestDatabaseEntities(); //var memberList = from mem in db.MemberInfo // where mem.miid == 28 // select mem; ////返回第一个元素或者null(没有元素的时候) FirstOrDefault(); //MemberInfo mbi = memberList.FirstOrDefault(); //if (mbi != null) //{ // //删除查出来的数据 // //db.MemberInfo.Remove(mbi); // //通过枚举标记数据的状态 标记为删除状态 // db.Entry<MemberInfo>(mbi).State = System.Data.Entity.EntityState.Deleted; // //更新到数据库中 // db.SaveChanges(); //} //else //{ // Response.Write("删除的数据不存在"); //} //方法2 常用 MemberInfo mbi = new MemberInfo() { miid = 29 }; db.Entry <MemberInfo>(mbi).State = System.Data.Entity.EntityState.Deleted; db.SaveChanges(); }
//更新按钮点击的时候 protected void Button4_Click(object sender, EventArgs e) { var db = new myTestDatabaseEntities(); var memberList = from mem in db.MemberInfo where mem.miid == 31 select mem; var mbi = memberList.FirstOrDefault(); mbi.miphone = "新的phone新的phone"; //把状态标记为更新 db.Entry <MemberInfo>(mbi).State = EntityState.Modified; db.SaveChanges(); }