LINQ to Entity里面不能使用DateTime

LINQ中不能直接使用DateTime，否则会报错：‘The specified type member 'Date' is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are support’

需要把DateTime定义在LINQ之外，例如：

            var now = DateTime.Now.Date;
            var query = from a in _workPeriodRepository.Table
                        where a.StartDate <= now && a.EndDate >= now
                        select a;
            return query.ToList();