JavaScript query for data in MongoDB by date _mongodb

GROUP BY date Aggregate query date statistics daily data (amount of information)
1

{ 
  "_id": ObjectId ("557ac1e2153c43c320393d9d"), 
  "Msgtype": "Text", 
  "Sendtime": Isodate ("2015-06-12t11 : 26:26.000z ") 
} 

2

{ 
  "_id": ObjectId ("557ac1ee153c43c320393d9e"), 
  "Msgtype": "Text", 
  "Sendtime": Isodate ("2015-06-12t11 : 26:38.000z ") 
} 

3

{ 
  "_id": ObjectId ("557ac2012de5d32d213963b5"), 
  "Msgtype": "Text", 
  "Sendtime": Isodate (" 2015-06-12t11:26:56.000z ") 
} 

4

{ 
  "_id": ObjectId ("557ac978bb31196e21d23868"), 
  "Msgtype": "Text", 
  "Sendtime": Isodate (" 2015-06-12t11:58:47.000z ") 
} 

5

{ 
  "_id": ObjectId ("557ac9afbb31196e21d23869"), 
  "Msgtype": "Text", 
  "Sendtime": Isodate ("2015-06-12t11 : 59:43.000z ") 
} 

SQL here

Db.getcollection (' Wechat_message '). Aggregate ( 
  [   
    {  $project: {day: {$substr: ["$sendTime", 0, 10]}}},< c10/>{  $group  : {_id: ' $day ', number: {$sum: 1}}}, 
    {  $sort  : {_id:-1}}     
  ] 
 

result here

"Result": [  
    { 
      "_id": "2015-07-06", 
      "number": 13.0000000000000000 
    },  
    { 
      "_id": "2015-07-05", 
      "number": 3.0000000000000000 
    },  
    {" 
      _id": "2015-07-03", 
      "number": 10.0000000000000000 
    },  
    { 
      "_id": "2015-07-02", 
      " Number ": 29.0000000000000000 
    }, 
]

3 Ways to query all the information for one day, query by date
MongoDB's query really makes people difficult to ponder, on the inquiry one day information, all need to spend a few kung fu to do.

The first way:

Coll.aggregate ([ 
     {$project: {senddate: {$substr: [' $sendTime ', 0,]}, Sendtime:1, Content:1}}, 
     {$match: { Senddate: ' 2015-07-05 '}}, 
    ] 

The second way (variation of the first kind):

Coll.aggregate ([ 
     {$match: {' sendtime ': {' $gte ': new Date (' 2015-07-05 '), ' $lt ': new Date (' 2015-07-06 ')}}} 

The Third Way (variation of the second kind):

Coll.aggregate ([ 
     {$match: {' sendtime ': {' $gte ': new Date (' 2015-07-05 00:00:00 '), ' $lte ': new Date (' 2015-07-05 23:59:59 ')}}} 

The query results are as follows (show one way: Other shows are slightly different):

[{_id:5599b09bc16aac90e9fb7995, senddate: ' 2015-07-05 '}, 
 {_id:5599b161c16aac90e9fb7996, senddate: ' 2015-07-05 '}, 
 {_id:5599b161c16aac90e9fb7997, senddate: ' 2015-07-05 '} ]