Linq OrderByDescending ThenByDescending问题 [英] Linq OrderByDescending ThenByDescending Issue
问题描述
您好，我对linq订购有疑问. 我有一个带有两个日期时间字段的对象.一个只会存储日期(例如2010年8月2日)，而将时间保留为全0
Hi im having a problem with ordering with linq. I have a object with two datetime fields. One just stores the date (e.g. 8/2/2010) and leaves the time as all 0's
在创建记录时会创建另一个datetime字段，同时还有时间.这两个字段的想法是因为我可能要在网站上添加几天前的标题/文章".因此，我选择的第一个Datetime是"Date"，通常默认为今天的日期.
While the other datetime field is created when the record is made and has the time on it as well. The idea of these two field are because I may want to add a "Headline/article" that is a couple days old to my site. So the first Datetime called "Date" is the one I pick, Generally this is defaulted to todays date.
我遇到的问题是我可以按日期排序，但是如果我在同一日期添加了许多文章(因此，在日期库中，它们的日期字段都相同)，则最新文章将放在这三个文章的底部！
Problem I have is I can order by The date but if I have a number of articles added on the same date (so in the datebase their date field are all identical) the newest article is put to the bottom of the three!
示例:
Article1-12/08/2010-12/08/2010 2:45 pm
Article2-12/08/2010-12/08/2010 3:45 pm
第3条-2010年12月8日-2010年12月8日下午4:45
Article4-11/08/2010-12/08/2010 2:50 pm
Example:
Article1 - 12/08/2010 - 12/08/2010 2:45pm
Article2 - 12/08/2010 - 12/08/2010 3:45pm
Article3 - 12/08/2010 - 12/08/2010 4:45pm
Article4 - 11/08/2010 - 12/08/2010 2:50pm
他们似乎只按日期字段排序，而不按日期字段排序，然后创建了日期字段，我以为我在使用命令时应该这样做(因为它们的日期字段相同)
they seem to only order by the date field and not date field then created date field which I assumed they should when I use the command (as their date fields are identical)
HeadlineRepository.All().OrderByDescending(x => x.Date).ThenByDescending(x => x.Created).Take(8)
这里有些失败，试图将它们交换，但是没有产生我想要的结果.似乎只是忽略了thenbydescending ...
Bit at a lose here tried to swap them both around but doesn't produce the result I want. seems that it just ignores the thenbydescending...
史蒂夫
已编辑
为大家提供更多信息
Headlines = repository.All().OrderByDescending(x => x.Date).ThenByDescending(x => x.Created)
产生(先显示日期，然后显示创建日期)
Produces (Date then Created displayed)
10/08/2010 00:00:00 10/08/2010 19:27:46
10/08/2010 00:00:00 10/08/2010 19:27:46
10/08/2010 00:00:00 10/08/2010 19:27:21
10/08/2010 00:00:00 10/08/2010 19:27:21
09/08/2010 00:00:00 10/08/2010 21:28:11
09/08/2010 00:00:00 10/08/2010 21:28:11
09/08/2010 00:00:00 09/08/2010 00:00:00
09/08/2010 00:00:00 09/08/2010 00:00:00
奉献时
Headlines = repository.All().OrderByDescending(x => x.Created).ThenByDescending(x => x.Date),
09/08/2010 00:00:00 10/08/2010 21:28:11
09/08/2010 00:00:00 10/08/2010 21:28:11
10/08/2010 00:00:00 10/08/2010 19:27:46
10/08/2010 00:00:00 10/08/2010 19:27:46
10/08/2010 00:00:00 10/08/2010 19:27:21
10/08/2010 00:00:00 10/08/2010 19:27:21
09/08/2010 00:00:00 09/08/2010 00:00:00
09/08/2010 00:00:00 09/08/2010 00:00:00
推荐答案
看来您的逻辑是正确的.我已经在控制台应用程序中复制了您的方案，网址为 http://pastebin.org/467317
It appears your logic is correct. I've reproduced your scenario in a console app at http://pastebin.org/467317
使用此语句将产生您期望的结果.
Using this statement produces the results you were expecting.
reg.OrderByDescending(x=>x.RegisteredOn)
.ThenByDescending(x=>x.StartsClassOn)
.Take(8)
您是将LINQ查询分配给变量还是确保按预期方式执行了该变量?
Are you assigning the LINQ query to a variable or ensuring somehow that it's executed as you expect?
这篇关于Linq OrderByDescending ThenByDescending问题的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
