Question

我有一个返回以下数据库表结果的查询：

我正在运行的查询正在运行。但是，我只想返回SiteID等于允许用户查看的 SiteID 的结果。
这在下表中定义：

现在，我的查询如下：

User user = ObjectContext.Users


        .Include("TeamMemberships")
            .First(u => u.UserID == userID);

        var teamIDs = user.TeamMemberships.Select(t => t.TeamID).ToList(); //This returns the Users team (Not important for now)
        var siteIDs = ObjectContext.SiteMemberships.Where(t => teamIDs.Contains(t.TeamID)).Select(t => t.SiteID).ToList(); //This returns the SiteIDs that the user is allowed to see

        int? ticketID = null;

        if (string.IsNullOrEmpty(text) == false)
        {
            if (text.StartsWith("#"))
                text = text.Substring(1);

            int temp;
            if (int.TryParse(text, out temp))
                ticketID = temp;
        }

        var tickets = ObjectContext.Tickets
          .Include("TicketPriority")
          .Include("TicketStatu")
          .Include("TicketType")
          .Include("TicketCategory")
          .Include("Server")
          .Include("Site")
          .Include("Detector")
          .Include("Detector.Site")
          .Include("Detector.Track")
          .Include("Team")
          .Include("User")
          .Include("User1")
          .Where(t => ticketID.HasValue ? t.TicketID == ticketID.Value : true)
          .Where(t => ticketID.HasValue ? true : t.StartedOn >= fromDate && t.StartedOn <= toDate)
          .Where(t => ticketID.HasValue ? true : ticketStatusID.HasValue ? ticketStatusID.Value == 100 ? t.TicketStatusID < 4 : t.TicketStatusID == ticketStatusID.Value : true)
          .Where(t => ticketID.HasValue ? true : ticketPriorityID.HasValue ? t.TicketPriorityID == ticketPriorityID.Value : true)
          .Where(t => ticketID.HasValue ? true : ticketCategoryID.HasValue ? t.TicketCategoryID == ticketCategoryID.Value : true)
          .Where(t => ticketID.HasValue ? true : createdByUserID.HasValue ? t.CreatedByUserID == createdByUserID.Value : true)
          .Where(t => ticketID.HasValue ? true : assignedToTeamID.HasValue ? t.AssignedToTeamID == assignedToTeamID.Value : true)
          .Where(t => ticketID.HasValue ? true : assignedToUserID.HasValue ? t.AssignedToUserID == assignedToUserID.Value : true);
            if (ticketID.HasValue == false && string.IsNullOrEmpty(text) == false)
                tickets = tickets.Where(e => e.Title.Contains(text));

            return tickets.OrderBy(t => t.TicketID);

现在，我尝试做的是添加一个额外的.Where语句，如：

.Where(t => siteIDs.Contains(t.SiteID));

然而，我一直收到错误：

对...的最佳重载方法匹配有一些无效的参数。

是否会产生此错误，因为我将非可空值与可空值进行比较，或者将其与其他内容进行比较？

C＃Where语句Nullable vs Non Nullable

0 个答案: