Mongo查询搜索更新一个$ elemmatch

Question

I'm having trouble updating my database. I have a surveys collection and each document is as follows:

{
    "_id": {
        "$oid": "5aaf4f7984521736d88db4bb"
    },
    "title": "4242 ",
    "body": "4242 ",
    "subject": "4242 ",
    "recipients": [
        {
            "email": "a@gmail.com",
            "responded": false,
            "_id": {
                "$oid": "5ab04084be3c1529bcbdcd6e"
            }
        },
        {
            "email": " b@gmail.com",
            "responded": false,
            "_id": {
                "$oid": "5ab04084be3c1529bcbdcd6d"
            }
        },
        {
            "email": " c@gmail.com",
            "responded": false,
            "_id": {
                "$oid": "5ab04084be3c1529bcbdcd6c"
            }
        },
        {
            "email": " d@gmail.com",
            "responded": false,
            "_id": {
                "$oid": "5ab04084be3c1529bcbdcd6b"
            }
        },
        {
            "email": " e@gmail.com",
            "responded": false,
            "_id": {
                "$oid": "5ab04084be3c1529bcbdcd6a"
            }
        }
    ],
    "_user": {
        "$oid": "5aa5edbf8887a21af8a8db4c"
    },
    "dateSent": {
        "$date": "2018-03-20T00:11:55.943Z"
    },
    "yes": 0,
    "no": 0,
    "__v": 0
}

I'm calling this on my back-end using mongoose to try and update my database whenever a user responded to a survey.

const Survey = mongoose.model('surveys');

Survey.updateOne(
    {
        _id: surveyId,
        recipients: {
            $elemMatch: { email: email, responded: false }
        }
    }, 
    {
        $inc: { [choice]: 1 },
        $set: { 'recipients.$.responded': true }
    }
).exec();

But the update is only successful when the query matches the first object in the recipients array. For example, this would work. The query successfully updates the survey document and the recipient subdocument.

Survey.updateOne(
    {
        _id: surveyId,
        recipients: {
            $elemMatch: { email: "a@gmail.com", responded: false }
        }
    }, 
    {
        $inc: { [choice]: 1 },
        $set: { 'recipients.$.responded': true }
    }
).exec();

But this doesn't work

Survey.updateOne(
    {
        _id: surveyId,
        recipients: {
            $elemMatch: { email: "b@gmail.com", responded: false }
        }
    }, 
    {
        $inc: { [choice]: 1 },
        $set: { 'recipients.$.responded': true }
    }
).exec();

These are my schemas

const surveySchema = new Schema({
    title: String,
    body: String,
    subject: String,
    recipients: [RecipientSchema],
    yes: { type: Number, default: 0 },
    no: { type: Number, default: 0 },
    _user: { type: Schema.Types.ObjectId, ref: 'User' },
    dateSent: Date,
    lastResponded: Date
});

const recipientSchema = new Schema({
    email: String,
    responded: { type: Boolean, default: false }
});

When I use node to try to query the database manually, it also only returns the survey when the query matches the first recipient subdocument.

This successfully finds the survey and returns it.

Survey.find(
    {   
        _id: "5aaf4f7984521736d88db4bb", 
        recipients: { 
            $elemMatch: {
                email: "a@gmail.com",
                responded: false
            }
    }
}).then(console.log)

These don't

Survey.find(
    {   
        _id: "5aaf4f7984521736d88db4bb", 
        recipients: { 
            $elemMatch: {
                email: "b@gmail.com",
                responded: false
            }
    }
}).then(console.log)

Survey.find(
    {   
        _id: "5aaf4f7984521736d88db4bb", 
        recipients: { 
            $elemMatch: {
                email: "c@gmail.com",
                responded: false
            }
    }
}).then(console.log)

I have been trying to look up how $elemMatch works and someone told me that I can't query the properties of objects inside the recipients array, and that I can only query its IDs.

Answer 1

问题是您在存储后续电子邮件时没有对它们进行修剪，因为您会看到只有第一封电子邮件已被正确修剪，而其余电子邮件的开头都有空白，使查询不返回任何内容。