c# - 仅显示两周的记录！从创造

Question

我遇到的问题是显示数据库中不超过 14 天的记录。这个想法是有人会创建一个广告，它只会显示两周。

我是 LinQ 的新手，发现这种查询的语法难以理解。

已创建以下查询以显示如下所示的所有广告。

var Adverts = from m in db. Adverts
 select m;

以下是我想要实现的目标。

var Adverts = from m in db. Adverts
where m.date  == DateTime.Now 

---- Unsure of how to input a date range ------

 select m;

欢迎任何建议。

Answer 1

var now = DateTime.Now;
var twoWeeksAgo = now.AddDays(-14);
var adverts = 
    from advert in db. Adverts
    where advert.date >= twoWeeksAgo && advert.date <= now
    select advert;

Answer 2

一行 lambda 应该让你：

var adverts = db.Adverts.Where(x => x.date >= DateTime.Now.AddDays(-14) && x.date <= DateTime.Now)

Answer 3

DateTime类实现IComparable。因此，您可以这样做。

var results = from ad in Adverts
              where ad.date <= DateTime.Now &&
                    ad.date >= DateTime.Now.AddDays(-14) 
              select ad;