//今日的官网零售收入
double? todayWebsite = dal.GetWhere(i => i.PayTime >= beginTime && i.PayTime <= endTime && (i.OrderFrom == 1 || i.OrderFrom == 0 || i.OrderFrom == null)).Sum(i => i.TotalMoney);
在这句代码中，PayTime、OrderFrom 列名都是在Order表中，麻烦你们给我把这句话转成SQL语句，谢谢.只剩下10分了，还请你们不要在意
------解决思路----------------------
SELECT SUM(TotalMony) FROM Order WHERE PayTime >= beginTime AND PayTime <= endTime AND (OrderFrom == 1 OR OrderFrom == 0 OR OrderFrom == null)