Mongoose 不在数组的 objectid 中填充 objectid

Posted 2023-03-10

【中文标题】Mongoose 不在数组的 objectid 中填充 objectid

【英文标题】：Mongoose do not populate objectid in an objectid of array

【发布时间】：2021-03-03 21:29:09

【问题描述】：

这个问题有点长。所以我为你粗体输入了关键信息。

我开发了一个类似 *** 的项目。我有 4 个数据库：

问题 用户 解决方案 cmets

我互相引用了这些架构。这是架构：

问题架构

const problemSchema = new mongoose.Schema(
    title: 
        type: String,
        required: [true, 'You have to enter a title']
    ,
    content: 
        type: String,
        required: [true, 'You have to enter a content']
    ,
    createdAt: 
        type: Date,
        default: Date.now()
    ,
    slug: 
        type: String
    ,
    solution: [
        
            type: mongoose.Schema.Types.ObjectId,
            ref: 'Solution'
        ,
    ],
    comment: [
        
            type: mongoose.Schema.Types.ObjectId,
            ref: 'Comment'
        
    ],
    votes: 
        type: Number,
        default: 0
    ,
    views: 
        type: Number,
        default: 0
    ,
    user: 
        type: mongoose.Schema.Types.ObjectId,
        required: true,
        ref: 'User'
    
)

module.exports = mongoose.model('Problem', problemSchema)

用户架构：

const userSchema = new mongoose.Schema(


    name: 
        type: String,
        required: true
    ,
    email: 
        type: String,
        required: [true, 'You have to enter an email'],
        unique: true,
        match: [
            /^([\w-\.]+@([\w-]+\.)+[\w-]2,4)?$/,
            'Please provide a valid email address.'
        ]
    ,
    password: 
        type: String,
        required: [true, 'You have to enter a password'],
        minlength: [6, 'Your password cannot be less than 6 character.'],
        select: false
    ,
    role: 
        type: String,
        default: 'user',
        enum: ['user', 'admin']
    ,
    createdAt: 
        type: Date,
        default: Date.now()
    ,
    about: 
        type: String
    ,
    place: 
        type: String
    ,
    age: 
        type: Number
    ,
    blocked: 
        type: Boolean,
        default: false
    ,
    problem: [
        
            type: mongoose.Schema.Types.ObjectId,
            ref: 'Problem'
        ,
    ],
    solution: [
        
            type: mongoose.Schema.Types.ObjectId,
            ref: 'Solution'
        
    ],
    comment: [
        
            type: mongoose.Schema.Types.ObjectId,
            ref: 'Comment'
        
    ]
)

和评论架构：

const commentSchema = new mongoose.Schema(
    content: 
        type: String,
        required: [true, 'You have to enter a content']
    ,
    createdAt: 
        type: Date,
        default: Date.now()
    ,
    isFunctional: 
        type: Boolean,
        default: false
    ,
    user: 
        type: mongoose.Schema.Types.ObjectId,
        required: true,
        ref: 'User'
    ,
    problem: 
        type: mongoose.Schema.Types.ObjectId,
        ref: 'Problem'
    ,
)


module.exports = mongoose.model('Comment', commentSchema)

在我的项目中，我将问题发送到 MongoDB。然后我发送评论。保存 cmets 后，我将这些 cmets 添加到问题和用户数据库中。

cmet 保存在 DB 中的函数：

const Comment = require('../models/comment/Comment')
const Problem = require('../models/problem/Problem')
const User = require('../models/user/User')
const asyncErrorWrapper = require('express-async-handler')

const addCommentToProblem = asyncErrorWrapper(async (req, res, next) => 

    const content, problemId = req.body
    
    const newComment = await Comment.create(
        content: content,
        problem: problemId,
        user: req.user.id,
    )

    const problemOfComment = await Problem.findByIdAndUpdate(problemId, 
        $push:  comment: newComment._id 
    )

    const userOfComment = await User.findByIdAndUpdate(req.user.id, 
        $push:  comment: newComment._id 
    )

)

好吧，到目前为止一切都很好。问题来了。当我尝试解决问题时，我会填充一些字段，例如用户字段。所以我可以在这个问题的细节中添加用户信息。在问题模式中填充用户和评论时，它会向我发送数据。不过，我们还好。但是当我尝试在 cmets 中获取用户字段时，它不会填充用户。它只是用户信息的objectId。

这是我遇到问题的功能：

const getAProblem = asyncErrorWrapper(async (req, res, next) => 

    const id = req.params

    const problems = null

    await Problem.findByIdAndUpdate(id, 
        $inc:  views: 1 
    ,  new: true )
    .populate('user') ==> THIS LINE WORKS
    .populate('comment') ==> THIS LINE WORKS
    .populate('comment.user') ==> THIS LINE DOES NOT WORK
    .exec(function(err, post) 
        if(err) 
            console.log(err)
        
        
        res
        .status(200)
        .json(
            success: true,
            data: post
        )
    );

)

感谢您的阅读和耐心。任何帮助将不胜感激。

【参考方案1】：

请参阅https://mongoosejs.com/docs/populate.html 的文档

然后试试这个方法。

const getAProblem = asyncErrorWrapper(async (req, res, next) => 

const id = req.params

const problems = null

await Problem.findByIdAndUpdate(id, 
    $inc:  views: 1 
,  new: true )
.populate('user') ==> THIS LINE WORKS
.populate(
   'path': 'comment',
   'populate': 
     'path':'user'
   
)
.exec(function(err, post) 
    if(err) 
        console.log(err)
    
    
    res
    .status(200)
    .json(
        success: true,
        data: post
    )
);
)