c# - where 子句中的 IN 运算符

Question

List<HelprClass.Organizer> org = 
    ( from EventOrg in cntx.EventOrganizer 
    from MstrOrg in cntx.Organizer
    where EventOrg.OrganizerID == MstrOrg.OrganizerID
    Select new HelprClass.Organizer
    {
    OrganizerName = MstrOrg.OrganizerName
    }).ToList()

现在我想在上面的查询中使用 IN Opeartor。这工作正常。

在 EventOrganizer 中我有 EventID 现在我只想选择 EventOrganizer 集合中存在的事件 ID

我有另一个 var varibale 的 EventID

Var EventID= From EvntID in Evetn Select new {ID= EvntID.EventID};

类似这样的东西

在哪里

    EventOrg.OrganizerID == MstrOrg.OrganizerID

    &&  EventOrg.EventID in EventID.ID

我怎样才能做到这一点？

我会感谢你的帮助

Answer 1

试试这个:

var EventIDs = from EvntID in Event select EvntID.EventID;

var org = (from EventOrg in cntx.EventOrganizer 
           from MstrOrg in cntx.Organizer
           where EventOrg.OrganizerID == MstrOrg.OrganizerID
           select new {E=EventOrg, M=MstrOrg}
          ).ToList();


org = org
        .Where(o => EventIDs.Contains(o.E.EventID) )
        .Select(o => new HelprClass.Organizer
           {
                OrganizerName = o.M.OrganizerName
           }
         );