Mongo投影仅用于字段和值

debugcn 发表于 Dev

丹妮

我有大量的文档，我只想用字段和值来投影它们。

像这样

{"p":{"s":{"status":"b"},"m":{"pd":{"tt":{"bi":"2","psi":"4","ircsi":true}},"mi":"TT","et":"2020-09-07T14:34:00+03:00"}}}
{"p":{"s":{"status":"b"},"m":{"pd":{"tt":{"bi":"20","psi":"1","ircsi":true}},"mi":"TT","et":"2020-12-29T08:28:06+03:00"}}}
.........

它有什么办法看起来像这样吗？

{"status":"b","bi":"2","psi":"4","ircsi":true,"mi":"TT","et":"2020-09-07T14:34:00+03:00"}}}
{"status":"b","bi":"20","psi":"1","ircsi":true,"mi":"TT","et":"2020-09-07T14:34:00+03:00"}}}
.........

我的查询是这样的；

db.s.aggregate([{
    "$match": { 
        "p.m.etm": {
            "$gt": 1585688401000,
            "$lt": 1610565947499
        },
        "p.m.mi":"TT"
    }
},
{
    "$project": {
        "p.m.pd.tt.bi": 1,
        "p.m.pd.tt.psi": 1,
        "p.m.pd.tt.ircsi": 1,
        "p.m.mi":1,
        "p.s.status":1,
        "p.m.et":1,
        "_id": 0
    }
}],
{
    "allowDiskUse": true
});

我应该改变什么才能达到我的需要？

当然

您可以$project用来创建新字段。（$match为方便起见，我将其移除）

db.collection.aggregate([
  {
    "$project": {
      "bi": "$p.m.pd.tt.bi",
      "psi": "$p.m.pd.tt.psi",
      "ircsi": "$p.m.pd.tt.ircsi",
      "mi": "$p.m.mi",
      "status": "$p.s.status",
      "et": "$p.m.et",
      "_id": 0
    }
  }
])

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