node.js - 在数组 Mongoose 中搜索对象

Question

假设我有一个名为“部门”的模型。我有一个包含房间的数组，每个房间都有一个病人(有一个病人)。

我想获取患者编号等于请求 ID 的患者。有办法实现这一点吗？

var department = mongoose.model('department', {
    departmentName: String,
    rooms: [
        {
            roomNumber: String,
            width: Number,
            height: Number,
            posX: Number,
            posY: Number,
            sanitary: Boolean,
            childcareArea: Boolean,
            lounge: Boolean,
            patient: {
                patientnr: Number,
                firstname: String,
                lastname: String,
                reasonOfHospitalization: String,
                dateOfHospitalization: Date,
                expectedDateOfDischarge: Date,
                vegetarian: Boolean,
                needsHelp: Boolean,
                comments: String,
                department: String,
                roomNumber: String,
                nextTreatment: {
                    type: String,
                    shortDescription: String,
                    timestamp: Date
                }
            }
        }
    ]
});

//get patient with id
app.get('/api/departments/patients/:id', function(req, res) {
    department.find({"patient": {$all :[60022]}}, function (err, patient) {
        if (err)
            res.send(err)
        res.json(patient);
    });
});

Answer 1

您可以使用$elemMatch 在您的投影中如下:

//get patient with id
app.get('/api/departments/patients/:id', function(req, res) {
    department.findOne(
        { "rooms.patient.patientnr": parseInt(req.params.id) }, 
        { 
            "rooms": {
                "$elemMatch": {
                    "patient.patientnr": parseInt(req.params.id)
                }
            }
        },
        function (err, dept) {
            if (err)
                res.send(err)
            var patient = dept.rooms[0].patient;
            res.json(patient);
        }
    );
});

或$ positional operator

//get patient with id
app.get('/api/departments/patients/:id', function(req, res) {
    department.findOne(
        { "rooms.patient.patientnr": parseInt(req.params.id) }, 
        { "rooms.$": 1 },
        function (err, dept) {
            if (err)
                res.send(err)
            var patient = dept.rooms[0].patient;
            res.json(patient);
        }
    );
});

或使用聚合框架:

//get patient with id
app.get('/api/departments/patients/:id', function(req, res) {
    department.aggregate(
        [
            { "$match": { "rooms.patient.patientnr": parseInt(req.params.id) } },
            {
                "$project": {
                    "room": {
                        "$arrayElemAt": [
                            {
                                "$filter": {
                                    "input": "$rooms",
                                    "as": "room",
                                    "cond": {
                                        "$eq": [
                                            "$$room.patient.patientnr", 
                                            parseInt(req.params.id)
                                        ]
                                    }
                                }
                            }, 0
                        ]
                    }
                }
            }
        ],  function (err, results) {
            if (err)
                res.send(err)
            var patient = results[0].room.patient;
            res.json(patient);
        }
    );
});