C# EF CodeFrist到现有数据库

C# EF CodeFrist到现有数据库,c#,asp.net-mvc,entity-framework,model-view-controller,C#,Asp.net Mvc,Entity Framework,Model View Controller,我想先学习EF 6代码到现有数据库(SQLServer) 当我尝试运行我的项目时,出现以下错误: 例外情况 System.ArgumentNullException:值不能为null。参数名称: 来源 控制器 public ActionResult Index() { var meetings = db.Meetings .OrderBy(e => e.StartDate) .Where(e => e.IsPublic) .Se

我想先学习EF 6代码到现有数据库(SQLServer)

当我尝试运行我的项目时,出现以下错误:

例外情况

System.ArgumentNullException:值不能为null。参数名称: 来源

控制器

public ActionResult Index()
{
    var meetings = db.Meetings
        .OrderBy(e => e.StartDate)
        .Where(e => e.IsPublic)
        .Select(e => new MeetingViewModel()
            {
                MeetingId = e.MeetingId,
                MeetingName = e.MeetingName,
                MeetingTypeName = e.MeetingType.Name,
                LocationName = e.MeetingLocation.Name,
                StartDate = e.StartDate,
            });

    var upcomingMeetings = meetings.Where(e => e.StartDate > DateTime.Now);
    var passedMeetings = meetings.Where(e => e.StartDate <= DateTime.Now);
    return View(HomeIndex, new HomePageModel());
}
public ActionResult Index()
{
var会议=db会议
.OrderBy(e=>e.StartDate)
.其中(e=>e.IsPublic)
.选择(e=>new MeetingViewModel()
{
MeetingId=e.MeetingId,
MeetingName=e.MeetingName,
MeetingTypeName=e.MeetingType.Name,
LocationName=e.MeetingLocation.Name,
起始日期=e.起始日期,
});
var upcomingMeetings=meetings.Where(e=>e.StartDate>DateTime.Now);
var passedMeetings=会议。其中(e=>e.StartDate x.UpcommingMeetings)
}

CONNECTIONSTRING是EF AutoGenerator,无需更改

您未在模型中传递集合,并且
UpcommingMeetings
会在视图中导致空异常错误

var upcomingMeetings = meetings.Where(e => e.StartDate > DateTime.Now);
var passedMeetings = meetings.Where(e => e.StartDate <= DateTime.Now);
return View(HomeIndex, new HomePageModel()
{
    UpcommingMeetings = upcomingMeetings,
    PassedMeetings = passedMeetings
});
var upcomingMeetings=meetings.Where(e=>e.StartDate>DateTime.Now);

var passedMeetings=meetings。其中(e=>e.StartDate您没有在模型中传递集合,
UpcommingMeetings
在视图中导致空异常错误

var upcomingMeetings = meetings.Where(e => e.StartDate > DateTime.Now);
var passedMeetings = meetings.Where(e => e.StartDate <= DateTime.Now);
return View(HomeIndex, new HomePageModel()
{
    UpcommingMeetings = upcomingMeetings,
    PassedMeetings = passedMeetings
});
var upcomingMeetings=meetings.Where(e=>e.StartDate>DateTime.Now);

var passedMeetings=meetings.Where(e=>e.StartDate)您可以发布错误的堆栈跟踪吗?将
upcomingMeetings
passedMeetings
分配给
新主页模型()
properties。请参考此。提供您的连接string@IvanStoev是的,我错过了,谢谢你和亲爱的Rainman你能发布错误的堆栈跟踪吗?将
upcomingMeetings
passedMeetings
分配给
新主页模型()怎么样
properties。请参考此。提供您的连接string@IvanStoev是的,我错过了,谢谢你们,亲爱的RainmanThank,我为此浪费了5小时的时间,我在寻找数据库迁移中的错误。因为所有类似的测试都将我与之联系在一起。谢谢!谢谢你们,我为此浪费了5小时的时间,我在寻找数据库迁移中的错误.因为所有类似的测验都把我和它联系了起来。谢谢!
var upcomingMeetings = meetings.Where(e => e.StartDate > DateTime.Now);
var passedMeetings = meetings.Where(e => e.StartDate <= DateTime.Now);
return View(HomeIndex, new HomePageModel()
{
    UpcommingMeetings = upcomingMeetings,
    PassedMeetings = passedMeetings
});