Question

我有以下指标集合：

{
    name: "Hello",
    values: [
        {
            value: 2629,
            date: "2016-10-28T07:00:00.000Z",
            _id: "58453abfef7aaa15ac1fdee8"
        },
        {
            value: 1568,
            date: "2016-10-29T07:00:00.000Z",
            _id: "58453abfef7aaa15ac1fdee7"
        },
        {
            value: 1547,
            date: "2016-10-30T07:00:00.000Z",
            _id: "58453abfef7aaa15ac1fdee6"
        },
        {
            value: 1497,
            date: "2016-10-31T07:00:00.000Z",
            _id: "58453abfef7aaa15ac1fdee5"
        },
        {
            value: 3031,
            date: "2016-11-01T07:00:00.000Z",
            _id: "58453abfef7aaa15ac1fdee4"
        },
        {
            value: 2559,
            date: "2016-11-02T07:00:00.000Z",
            _id: "58453abfef7aaa15ac1fdee3"
        },
        {
            value: 2341,
            date: "2016-11-03T07:00:00.000Z",
            _id: "58453abfef7aaa15ac1fdee2"
        },
        {
            value: 2188,
            date: "2016-11-04T07:00:00.000Z",
            _id: "58453abfef7aaa15ac1fdee1"
        },
        {
            value: 3280,
            date: "2016-11-05T07:00:00.000Z",
            _id: "58453abfef7aaa15ac1fdee0"
        },
        {
            value: 4638,
            date: "2016-11-06T07:00:00.000Z",
            _id: "58453abfef7aaa15ac1fdedf"
        }
    ]
},
.... more of the same

我想得到的是自定义日期范围之间的所有值。我已经尝试了以下查询，但仍然会返回整个值数组：

{
    name: "Hello", 
    values: {
        $elemMatch: {
            date: {
                $lt: "2016-11-03T07:00:00.000Z", 
                $gt: "2016-10-28T07:00:00.000Z" 
            }
        }
    }
}

也许我以错误的格式保存了日期？任何帮助将不胜感激。

Answer 1

MongoDB 2.2+中的Aggregation框架提供了Map / Reduce的替代方案。 $unwind运算符可用于将values数组分隔为可匹配的文档流：

db.tmp.aggregate(
    // Start with a $match pipeline which can take advantage of an index and limit documents processed
    { $match : {
        name: "Hello",
        "values.date": {
            $lt: "2016-11-03T07:00:00.000Z",
            $gt: "2016-10-28T07:00:00.000Z" }
    }},
    { $unwind : "$values" },
    { $match : {
        name: "Hello",
        "values.date": {
            $lt: "2016-11-03T07:00:00.000Z",
            $gt: "2016-10-28T07:00:00.000Z" }
    }}
)

示例输出：

{
"_id":ObjectId("5845432720ce37bdc7e9ca1c"),
   "name":"Hello",
   "values":{  
      "value":1568,
      "date":"2016-10-29T07:00:00.000Z",
      "_id":"58453abfef7aaa15ac1fdee7"
   }
},{  
   "_id":ObjectId("5845432720ce37bdc7e9ca1c"),
   "name":"Hello",
   "values":{  
      "value":1547,
      "date":"2016-10-30T07:00:00.000Z",
      "_id":"58453abfef7aaa15ac1fdee6"
   }
},{  
   "_id":ObjectId("5845432720ce37bdc7e9ca1c"),
   "name":"Hello",
   "values":{  
      "value":1497,
      "date":"2016-10-31T07:00:00.000Z",
      "_id":"58453abfef7aaa15ac1fdee5"
   }
},{  
   "_id":ObjectId("5845432720ce37bdc7e9ca1c"),
   "name":"Hello",
   "values":{  
      "value":3031,
      "date":"2016-11-01T07:00:00.000Z",
      "_id":"58453abfef7aaa15ac1fdee4"
   }
},{  
   "_id":ObjectId("5845432720ce37bdc7e9ca1c"),
   "name":"Hello",
   "values":{  
      "value":2559,
      "date":"2016-11-02T07:00:00.000Z",
      "_id":"58453abfef7aaa15ac1fdee3"
   }
}

MongoDB / Mongoose - 按日期查询对象数组

1 个答案: