猫鼬模式参考返回未定义

Question

我只是想从 productSchema 中引用 accountSchema，但我收到了一个未定义的结果。我想我已经正确地引用了“帐户”，并且我正在正确地创建和保存产品。我的理解是 account 字段应该使用适当的 account objectId 填充自己，只是在模型中被引用。

//acount.model.js
const accountSchema = new Schema({
    email: { type: String, unique: true, required: true },
    passwordHash: { type: String, required: true },
    title: { type: String, required: true },
    firstName: { type: String, required: true },
    lastName: { type: String, required: true },
    acceptTerms: Boolean,
    role: { type: String, required: true },
    verificationToken: String,
    verified: Date,
    resetToken: {
        token: String,
        expires: Date
    },
    passwordReset: Date,
    created: { type: Date, default: Date.now },
    updated: Date
});
module.exports = mongoose.model('Account', accountSchema);

//product.model.js
const productSchema = new Schema({
    title: { type: String, trim: true, required: true },
    description: { type: String, trim: true, required: true },
    category: { type: String, trim: true},
    subCategory: { type: String, trim: true },
    quantity: { type: Number, trim: true },
    price: { type: Number, trim: true },
    created: { type: Date, default: Date.now },
    updated: Date,
    account: { type: Schema.Types.ObjectId, ref: 'Account' }
});

module.exports = mongoose.model('Product', productSchema);

//products.controller.js

//routes
router.post('/', authorize([Role.Admin, Role.Vendor]), createSchema, create);

function createSchema(req, res, next) {
    const schema = Joi.object({
        title: Joi.string().required(),
        description: Joi.string().required(),
        category: Joi.string(),
        subCategory: Joi.string(),
        quantity: Joi.number(),
        price: Joi.number()
    });
    validateRequest(req, next, schema);
}

function create(req, res, next) {
    productService.create(req.body)
        .then(product => res.json(product))
        .catch(next);
        
}

//product.service.js
async function create(params) {
    const product = new db.Product(params);
    // save account
    await product.save();
    // res.json(product);
    console.log(basicDetails(product));
    return basicDetails(product);
    
}

function basicDetails(product) {
    const { id, title, description, category, subCategory, quantity, price, account } = product;
    return { id, title, description, category, subCategory, quantity, price, account };
}

//console.log output of basicDetails(product)
{
  id: '600614014d927f29a0fbb162',
  title: 'delete from mcjaggerrrrrrrr6789',
  description: 'testing delete from role.vendor mcjaggerrrrrrrrrr',
  category: undefined,
  subCategory: undefined,
  quantity: undefined,
  price: undefined,
  account: undefined
}

category、subCat、quant 和 price 都未定义，因为我没有为它们输入值，但 account 未定义，我不知道为什么。任何帮助表示赞赏！