日期时间比较错误 [英] Wrong datetime comparison

问题描述

var db = new XDataContext();
var q = from t in db.Posts select t;
var to = new DateTime(2011, 2, 1).AddMilliseconds(-1);          
q = q.Where(n => n.Date <= to);
foreach (var qq in q)
	// I get FEBRUARY items here!!!

为什么我会在2月收到她的短信?我知道，可以用不同的方法完成，但是我很困惑为什么以这种方式编码时它会失败.注意:此处涉及的类型均为日期时间.

谢谢

Julio

Why do I get February itmes her?? I Know, it could be done differently, but I''m puzzled why it fails when coded this way. Note: types involved here are all datetime.

Thanks

Julio

推荐答案

您期望得到的结果是什么?

DateTime结构以以下格式显示值:

What is the result you are expecting?

The DateTime struct show values in this format:

DateTime(yyyy,mm,dd)

由于代码中的month为2，它将显示2月的值.

Since month is 2 in your code, it will show values from february.

您已使用01-Fab-2011初始化了DateTime变量.

即使您减去1毫秒，它仍然保持01-Fab-2011.

因此，您将获得二月"项目.

确保要减去天/月或其他日期.

You have initialized your DateTime variable with 01-Fab-2011.

Even if you substract 1 Millisecond, it still remains 01-Fab-2011.

Hence you are getting "February" items.

Make sure if you want to substract Days/Months or something else.

浏览以下链接并获取C#DateTime基础.
DateTime.AddMilliseconds方法
DateTime.AddSeconds方法

终于
日期时间结构

System.DateTime方法(LINQ to SQL)

Navigate the following links and get the C# DateTime basics.
DateTime.AddMilliseconds Method
DateTime.AddSeconds Method

Finally
DateTime Structure

System.DateTime Methods (LINQ to SQL)

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