Question

我有这样的输出，但我想通过_id过滤事件数组，这与父对象_id相同。我想根据这种条件对其进行过滤。

[
    {
        "_id": "5cc45eb430aaba3cdc045dc0" ,
        "word": "Pasta",
        "translate": "Makarna",
        "kind": "İsim",
        "exampleSentence": "asljdalsd",
        "__v": 0,
        "events": [
            {
                "_id": "5cc45eb430aaba3cdc045dc0",
                "createdAt": "2019-04-27T13:52:15.721Z",
                "TenMinutesLater": "2019-04-27T13:52:25.721Z",
                "OneWeekLater": "2019-05-04T13:52:15.721Z",
                "OneMonthLater": "2019-05-27T13:52:15.721Z",
                "FourMonthLater": "2019-08-27T13:52:15.721Z",
                "__v": 0
            },
            {
                "_id": "5cc45ee630aaba3cdc045dc1",
                "createdAt": "2019-04-27T13:52:15.721Z",
                "TenMinutesLater": "2019-04-27T13:52:25.721Z",
                "OneWeekLater": "2019-05-04T13:52:15.721Z",
                "OneMonthLater": "2019-05-27T13:52:15.721Z",
                "FourMonthLater": "2019-08-27T13:52:15.721Z",
                "__v": 0
            }
        ]
    }
]

我想过滤与父对象_id具有相同_id属性的事件数组。如何根据我的查询查询？

这是我的查询

Word.find({ _id: req.params.id }, (err, words) => {
    if (err) {
      console.log(err);
    }
    const uid = words.map(word => word._id);
    console.log(req.params.id);
    Word.aggregate([
      {
        $match: {
          _id: {
            $in: uid.map(function(id) {
              return new mongoose.Types.ObjectId(id);
            })
          }
        }
      },
      {
        $lookup: {
          from: "tests",
          localField: "eventId",
          foreignField: "_id.str",
          as: "events"
        }
      }
    ])
      .then(data => {
        res.json(data);
      })
      .catch(err => {
        throw err;
      });
  });

我想要这样的输出。如何使用父对象的_id对其进行过滤？

[
    {
        "_id": "5cc45eb430aaba3cdc045dc0" ,
        "word": "Pasta",
        "translate": "Makarna",
        "kind": "İsim",
        "exampleSentence": "asljdalsd",
        "__v": 0,
        "events": [
            {
                "_id": "5cc45eb430aaba3cdc045dc0",
                "createdAt": "2019-04-27T13:52:15.721Z",
                "TenMinutesLater": "2019-04-27T13:52:25.721Z",
                "OneWeekLater": "2019-05-04T13:52:15.721Z",
                "OneMonthLater": "2019-05-27T13:52:15.721Z",
                "FourMonthLater": "2019-08-27T13:52:15.721Z",
                "__v": 0
        ]
    }
]

Answer 1

谢谢您的回答，但我终于解决了这样的问题。它运行正常

Word.find({ _id: req.params.id }, (err, words) => {
    if (err) {
      console.log(err);
    }
    const uid = words.map(word => word._id);
    Word.aggregate([
      {
        $match: {
          _id: {
            $in: uid.map(function(id) {
              return mongoose.Types.ObjectId(id);
            })
          }
        }
      },
      {
        $lookup: {
          from: "tests",
          localField: "_id.str",
          foreignField: "eventId",
          as: "events"
        }
      },
      {
        $addFields: {
          events: {
            $filter: {
              input: "$events",
              as: "event",
              cond: {
                $eq: ["$$event._id", mongoose.Types.ObjectId(req.params.id)]
              }
            }
          }
        }
      }
    ])
      .then(data => {
        res.json(data);
      })
      .catch(err => {
        throw err;
      });
  });

如何通过通用_id字段过滤事件数组？

1 个答案: