日期查询适用于_id，但不适用于日期值-MongoDB [英] Date query works with _id but not with Date value - MongoDB

问题描述

所以，我几个小时以来一直在尝试这种方法，但是没有得到任何结果.

So, I have been trying this since hours but didn't get any results.

我有一个MongoDB集合，它的日期值是"scrape_systemTime"，我要用scrape_systemTime : new Date()插入它.

I have a MongoDB collection which has a date value "scrape_systemTime", I am inserting it with scrape_systemTime : new Date().

我正在尝试使用以下方法获得比一周大的结果:

I am trying to get results that are one week older by using:

db.scrape.find({scrape_systemTime: { $lt: new Date( Date.now() - 86400000*7)}})

应该返回一组看起来像下面的Object的文档，但是什么也不返回. (请查看"scrape_systemTime"属性，该属性的日期早于一周.)

Which should return a set of documents that looks like an Object below, but it returns nothing. (Look at the "scrape_systemTime" attribute, which has a week older date.)

[{
        "newspaperID" : "6",
        "scrape_systemTime" : "Fri Oct 25 2013 13:14:10 GMT+0000 (UTC)",
        "_id" : ObjectId("526a6ea1985ba76408000010"),
        "languageID" : "1",
        "scrape_tabs_title" : "India",
        "scrape_tabs_href" : "http://www.indianexpress.com/supplement/India/798/",
        "scrape_thumb" : "images/default/noimage.jpg",
        "scrape_href" : "http://www.indianexpress.com/news/political-parties-woo-chhattisgarh-youth-on-facebook-whatsapp/1187180/",
        "scrape_title" : "Political parties woo Chhattisgarh youth on Facebook, WhatsApp",
        "scrape_largeimage" : "http://static.indianexpress.com/m-images/Fri Oct 25 2013, 17:57 hrs/M_Id_433064_facebook.jpg",
        "scrape_detail_article_text" : "",
        "scrape_newstime" : "PTI : Raipur, Fri Oct 25 2013, 18:11 hrs",
        "scrape_status" : "Pending",
        "viewCount" : 0,
        "error_log" : "OK",
        "ip" : "192.168.0.101"
}, ...]

但是如果我将_id用于日期条件，即使用一个星期的时间戳创建ObjectId()并在查询中使用如下:

But if I use the _id for date condition, i.e. create ObjectId() with one week old timestamp and use in query as below:

db.scrape.find({_id: { $lt: ObjectId( Math.floor( new Date( Date.now() - 86400000*7 ) / 1000 ).toString(16) + '0000000000000000')}})

它返回预期的结果.

为什么会这样?第一种查询语法有什么问题吗?

Why is this happening? Is anything wrong there in the first query syntax?

此处的图片

谢谢.

推荐答案

文档中的scrape_systemTime字段是字符串，而不是Date，这说明了您的查询无法正常工作的原因.

The scrape_systemTime field in your document is a string, not a Date which explains why your query isn't working.

所以一定是您没有像您想的那样插入文档，因为如果您将该字段插入为:

So it must be that you're not inserting your docs as you think you are, as you'd get strings like this if you inserted that field as:

scrape_systemTime: Date()

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