linq时间筛选以及list时间筛选

//写法一：正常
IEnumerable<x> xList = dbContext.xs.OrderByDescending(u => u.CreateTime).Where(u => EntityFunctions.DiffDays(u.CreateTime, DateTime.Now) == 0);
//写法二：错误
IEnumerable<x> xList = dbContext.xs.OrderByDescending(u => u.CreateTime);
xList = xList.Where(u => EntityFunctions.DiffDays(u.CreateTime, DateTime.Now) == 0);
写法二中，在使用EntityFunctions的时候，xList对象已经是Ienumerable的类型了，是无法使用linq自带的EntityFunctions方法的，所以会报错，具体意思就是不识别这个方法

#region List获取
            List<TestObj> list = new List<TestObj>();
            for (int i = 0; i < 4; i++)
            {
                TestObj temp = new TestObj() { ID = i, CreateTime = DateTime.Now.AddYears(-i).AddDays(i) };
                list.Add(temp);
            }
           Console.WriteLine( SerializationHelper.JsonSerialize(list.Where(u => DateTime.Compare(u.CreateTime.Date, DateTime.Now.AddYears(-1).AddDays(1).Date) == 0).ToList()));
           Console.WriteLine( DateTime.Now.Date);
            #endregion