mongodb - Mongdb 聚合在第一组阶段输出中进行第二组
问题描述
我不知道这是否可能,但我想从聚合管道获得特定的输出。
示例对象:
{
"_id": "6001d736e6dc1c55e893158d",
"manager": "6000da590ed6253807158216",
"label": "Test",
"identifier": "Test",
"interval": 11,
"unit": "X",
"created_at": "2021-01-15T17:56:06.749Z",
"updated_at": "2021-01-21T12:21:35.670Z",
"__v": 0
},
{
"_id": "6030236f976756b0b2d74556",
"manager": "6022f3285752fec73393bda2",
"label": "Temperature salon",
"identifier": "DS18B20_TEMP",
"interval": 60,
"unit": "°C",
"created_at": "2021-02-19T20:45:35.847Z",
"updated_at": "2021-02-19T20:45:35.847Z",
"__v": 0
}
我正在尝试按日期和单位(对象中的字段)获取一个组,我成功地分开做,但我找不到在同一管道中做这两个的解决方案。
如果我按月进行第一组的预期输出:
{
"_id": "2021-01-00T00:00:00.000Z",
"X": objectsArray[],
"°C": objetcsArray[]
},
{
"_id": "2021-02-00T00:00:00.000Z",
"X": objectsArray[],
"°C": objetcsArray[]
}
我目前在这个小组中拥有的东西:
{
'_id': {
'$add': [
{ '$subtract': [
{ '$subtract': [ '$created_at', new Date(0) ] },
{ '$mod': [
{ '$subtract': [ '$created_at', new Date(0) ] },
this.millisecondsIn(interval),
]},
]},
new Date(0),
]
},
sensors: {
$addToSet: '$$ROOT',
},
}
{
"_id": "2021-01-21T00:00:00.000Z",
"sensors": [
{
"_id": "601ab8f623224a5387c6252d",
"manager": "6000da590ed6253807158216",
"label": "Test",
"identifier": "Test2",
"interval": 60,
"unit": "°C",
"created_at": "2021-02-03T14:53:42.538Z",
"updated_at": "2021-02-03T14:53:42.538Z",
"__v": 0
},
{
"_id": "6029ad3dda9bafb99cf0b4d5",
"manager": "6022f3285752fec73393bda2",
"label": "Test sensor 1",
"identifier": "RANDOMID",
"interval": 60,
"unit": "°C",
"created_at": "2021-02-14T23:07:41.255Z",
"updated_at": "2021-02-14T23:07:41.255Z",
"__v": 0
}
]
},
{
"_id": "2020-12-24T00:00:00.000Z",
"sensors": [
{
"_id": "6001917f41c38212a477a2ce",
"manager": "6000da590ed6253807158216",
"label": "Test label",
"identifier": "TEst id",
"interval": 10,
"unit": "%",
"created_at": "2021-01-15T12:58:39.514Z",
"updated_at": "2021-01-16T19:08:40.239Z",
"__v": 0
},
{
"_id": "6001d736e6dc1c55e893158d",
"manager": "6000da590ed6253807158216",
"label": "Test",
"identifier": "Test",
"interval": 11,
"unit": "X",
"created_at": "2021-01-15T17:56:06.749Z",
"updated_at": "2021-01-21T12:21:35.670Z",
"__v": 0
}
]
},
{
"_id": "2021-02-18T00:00:00.000Z",
"sensors": [
{
"_id": "6030238d976756b0b2d74557",
"manager": "6022f3285752fec73393bda2",
"label": "Taux d'humidité salon",
"identifier": "DHT_22_HUM",
"interval": 60,
"unit": "%",
"created_at": "2021-02-19T20:46:05.042Z",
"updated_at": "2021-02-19T20:46:05.042Z",
"__v": 0
},
{
"_id": "60302357976756b0b2d74555",
"manager": "6022f3285752fec73393bda2",
"label": "Temperature salon",
"identifier": "DTH_22_TEMP",
"interval": 60,
"unit": "°C",
"created_at": "2021-02-19T20:45:11.071Z",
"updated_at": "2021-02-19T20:45:11.071Z",
"__v": 0
},
{
"_id": "6030236f976756b0b2d74556",
"manager": "6022f3285752fec73393bda2",
"label": "Temperature salon",
"identifier": "DS18B20_TEMP",
"interval": 60,
"unit": "°C",
"created_at": "2021-02-19T20:45:35.847Z",
"updated_at": "2021-02-19T20:45:35.847Z",
"__v": 0
}
]
}
有谁知道想要的输出是否可能,如果是,如何?
谢谢
解决方案
一般步骤是:
- $group by
unit
anddate
,将所有文档推送到传感器数组中 - $project 用 {k: <unit value>, v: <sensors array>} 创建一个新字段
- $group 按日期,将新字段推入数组
- $project 与 $arrayToObject 转换数组
- $addFields 在新对象中包含日期
- $replaceRoot 提升新对象
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