MongoDb使用Robomongo在dateTimes之间搜索嵌套数组

问题描述

我是MongoDb的新手，正在尝试看看是否可以使用它来存储时间序列数据.

I am very new to MongoDb and experimenting to see if I can use it to store time series data.

我插入了以下数据...

I have inserted the following data...

{
"_id" : ObjectId("5785f186ed936527c05efa10"),
"Timestamp" : ISODate("2006-07-13T07:42:00.000Z"),
"Label1" : "Lab1",
"Attr" : "atrr1",
"Readings" : [ 
    {
        "DateTime" : ISODate("2006-07-13T07:42:06.355Z"),
        "Value" : "22"
    }, 
    {
        "DateTime" : ISODate("2006-07-13T07:42:07.355Z"),
        "Value" : "22"
    }, 
    {
        "DateTime" : ISODate("2006-07-13T07:42:08.355Z"),
        "Value" : "22"
    }, 
  ....

因此，每个文档都是数组Readings，它们以1秒的间隔保存DateTimes.

So, each document as the array Readings that hold DateTimes in 1 second intervals.

因此，如果要在2个日期时间之间进行查询，请在 Robomongo 查询窗口中尝试以下操作.

So, if I want to query between 2 datetimes, I am trying the following in the Robomongo query window...

db.getCollection('Timedata').find(
 {
 'Readings.DateTime':    
    { $gt: '2005-07-13 07:42:13.355Z',  $lt: '2010-07-13 07:42:13.355Z'}        
  })

但是，它总是返回Fetched 0 record(s) in 11ms，而实际上应该全部返回.

However this always returns Fetched 0 record(s) in 11ms where as it should actually return them all.

我的语法必须不正确，但是我只是无法找到它的问题以及如何在嵌套数组中搜索日期时间.会有人有什么想法吗?

My syntax must be incorrect, but I just cannot find what is wrong with it and how to search for datetimes in a nested array as I have here. Would anyone have any ideas?

提前谢谢！

推荐答案

db.getCollection('Timedata').find(
 {
 Readings: {
   $elemMatch: 
     {DateTime: 
        {
            $gt: ISODate('2005-07-13 07:42:13.355Z'),
            $lt: ISODate('2010-07-13 07:42:13.355Z')
        }
     }
  }   
});


db.getCollection('Timedata').aggregate([
    {
        $match:{
        Readings: {
           $elemMatch: 
             {DateTime: 
                {
                    $gt: ISODate('2005-07-13 07:42:13.355Z'),
                    $lt: ISODate('2010-07-13 07:42:13.355Z')
                }
             }
          } 
        }
    },
   {
      $project: {
         _id:1,
         Timestamp:1,
         Label1:1,
         Attr:1,
         Readings: {
            $filter: {
               input: "$Readings",
               as: "item",
               cond: { 
                   $and: [
                        {$gt: [ "$$item.DateTime", ISODate('2006-07-13 07:00:13.355Z') ]},
                        {$lt: ["$$item.DateTime", ISODate('2010-07-15 07:42:13.355Z')]}
                   ]
               }
            }
         }
      }
   }
])

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