pymongo：如何從mongodb中提交多個結果？

Question

我想獲取python3 pymongo通過“名稱”建立的“數據”主題中的每個“ ecg_raw”。

如果我知道'name'和'time_info'，我如何獲取4個ECG_RAW數據，其中time_info =='2018-09-01 00:00:03'

我想獲取每個[[8,2]，[1,10]，[9,4]，[1,9]]之類的ecg_raw數據

我試過了

db.g.find({"data":{"$elemMatch":{"time_info":"2018-09-01 00:00:03"}}},{"name":1,"data":{"$elemMatch":{"time_info":"2018-09-01 00:00:03"}}})

但它只返回一個值，例如bottom。

{'_id': ObjectId('5b90d401219e9c9f72cac8c4'), 'name': 'testDog3', 'data': [{'time_info': '2018-09-01 00:00:03', 'ecg_raw': [8, 2]}]}

請幫我。

> db.g.find().pretty()
{
"_id" : ObjectId("5b90d401219e9c9f72cac8c4"),
"name" : "testDog3",
"data" : [
    {
        "time_info" : "2018-09-01 00:00:03",
        "ecg_raw" : [
            8,
            2
        ]
    },
    {
        "time_info" : "2018-09-01 00:00:03",
        "ecg_raw" : [
            1,
            10
        ]
    },
    {
        "time_info" : "2018-09-01 00:00:03",
        "ecg_raw" : [
            9,
            4
        ]
    },
    {
        "time_info" : "2018-09-01 00:00:03",
        "ecg_raw" : [
            1,
            9
        ]
    },
    {
        "time_info" : "2018-09-01 00:00:04",
        "ecg_raw" : [
            10,
            6
        ]
    },
    {
        "time_info" : "2018-09-01 00:00:04",
        "ecg_raw" : [
            1,
            6
        ]
    }
]
}

Answer 1

嘗試這個。

聚合（[{$ match：{'name'：'testDog3'}}，{“ $ unwind”：“ $ data”}，{“ $ match”：{“ data.time_info”：“ 2018-09-01 00 ：00：03" }}]）