猫鼬子文档 field.id 给出未定义

Posted 2023-03-10

【中文标题】猫鼬子文档 field.id 给出未定义

【英文标题】：mongoose subdocument field.id giving undefined

【发布时间】：2019-05-19 10:15:23

【问题描述】：

在此代码中，我需要使用其生成的 id 获取 batch_results，如中所述 猫鼬文档

const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const config = require('../config/config');



// Result schema
const ResultsSchema = new Schema(
    subject_id: 
        type: mongoose.SchemaTypes.ObjectId,
        required: false
    ,
    marks: 
        type: [String], // when needed to store absent as well
        required: false
    
);

// Batch Schema
const BatchSchema = new Schema(
    student_base_no: 
        type: mongoose.SchemaTypes.ObjectId,
        required: false,
    ,
    results: [ResultsSchema]
);

// Marks schema
const MarksSchema = new Schema(

    date: 
        type: Date,
        default: Date.now,
        required: true
    ,
    year: 
        type: String,
        default: (new Date).getFullYear(),
        required: true
    ,
    batch: 
        type: String,
        required: true
    ,
    batch_results: [BatchSchema]

);



const Marks = module.exports = mongoose.model('marks', MarksSchema, 'marks');

使用此代码我尝试获取输出，

var a = Marks.batch_results.id(id)

但它一直说 Cannot read property 'id' of undefined

我尝试了很多，但效果不佳:( 请帮帮我...

【参考方案1】：

您需要更改批次和标记架构：

const BatchSchema = new Schema(
    student_base_no: 
        type: mongoose.SchemaTypes.ObjectId,
        required: false,
    ,
    results:
         type: Schema.Types.ObjectId,
          ref: 'results' 
       
)