/// <summary> /// 删除 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> protected void Button4_Click(object sender, EventArgs e) { StudyEntities studyEntities = new StudyEntities(); //var userInfoList = from u in studyEntities.UserInfo // where u.UserId == 1166 // select u; //UserInfo userInfo = userInfoList.FirstOrDefault();//返回第一个元素,如果没有则返回NULL //if (userInfo != null) //{ // //studyEntities.UserInfo.Remove(userInfo); // studyEntities.Entry<UserInfo>(userInfo).State = EntityState.Deleted; // studyEntities.SaveChanges(); //} //else //{ // Response.Write("删除的数据不存在"); //} //若要用Remove 则UserInfo对象需从EF中获取才可用; //而通过设置State的方式则不需要如此; UserInfo userInfo = new UserInfo() { UserId = 1162 }; //studyEntities.UserInfo.Remove(userInfo); studyEntities.Entry <UserInfo>(userInfo).State = EntityState.Deleted; studyEntities.SaveChanges(); }
/// <summary> /// 更新 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> protected void Button5_Click(object sender, EventArgs e) { StudyEntities db = new StudyEntities(); var userInfoList = from u in db.UserInfo where u.UserId == 1163 select u; var userInfo = userInfoList.FirstOrDefault(); userInfo.UserPwd = "666666"; db.Entry <UserInfo>(userInfo).State = EntityState.Modified; db.SaveChanges(); }