SQL Server CE LINQ中的日期时间逻辑

我的对象“Job”具有LastTimeFinishedRunning（日期时间）和RunIntervalMinutes（整数）。我需要将它们相加，并与当前时间进行比较

大概是这样的：

Job jobToRun = ctx.Jobs.Where
(job => DateTime.Now > Job.LastTimeFinishedRunning.Add(TimeSpan.FromMinutes(job.RunIntervalMinutes))).FirstOrDefault();

long ticks = DateTime.Now.Ticks;
Job jobToRun = ctx.Jobs.Where
(job => ticks > Job.LastTimeFinishedRunning + job.RunIntervalMinutes * 1000 * 10000).FirstOrDefault();

当然，添加不起作用

这两者都不起作用：

DateTime.Now > EntityFunctions.AddMinutes(job.LastTimeFinishedRunning, job.RunIntervalMinutes)

或者这个：

DateTime.Now > System.Data.Objects.SqlClient.SqlFunctions.DateAdd("minute", job.RunIntervalMinutes, job.LastTimeFinishedRunning)

…因为它是SQL Server CE提供程序

有什么建议吗？Thx

更新：

我想我唯一的选择是通过在DB中将标记从DateTime切换到long来在LastTimeFinishedRunning中存储标记。所以代码看起来像这样：

Job jobToRun = ctx.Jobs.Where
(job => DateTime.Now > Job.LastTimeFinishedRunning.Add(TimeSpan.FromMinutes(job.RunIntervalMinutes))).FirstOrDefault();

long ticks = DateTime.Now.Ticks;
Job jobToRun = ctx.Jobs.Where
(job => ticks > Job.LastTimeFinishedRunning + job.RunIntervalMinutes * 1000 * 10000).FirstOrDefault();