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如何链接猫鼬中的两个模型?

mongoose express mongodb node.js javascript

asd qwe · 技术社区 · 1 年前

有两种模型,ProductModel和CategoryModel。

目的:创建产品(ProductModel)时,分别为其分配一个类别,类别集合中应该填写一个产品数组,但它们之间的连接不起作用。创建产品(ProductModel)时我通过json输出响应,它包含除类别字段外的所有字段,我也需要填写此字段。

产品型号

import { Schema, model } from 'mongoose'

const ProductModel = new Schema({
    productName: { type: String, required: true },
    price: { type: Number, required: true },
    preview: { type: String },
    color: { type: String, required: true },
    specs: {
        images: [{ type: String }],
        memory: { type: Number },
        ram: { type: Number },
        diagonal: { type: String },
    },
    category: {
        name: String,
        type: Schema.Types.ObjectId,
        ref: 'Category',
    },
})

export default new model('Product', ProductModel)

类别模型

import { Schema, model } from 'mongoose'

const CategoryModel = new Schema({
    name: {
        type: String,
        required: true,
    },
    products: [
        {
            type: Schema.Types.ObjectId,
            ref: 'Product',
        },
    ],
})

export default new model('Category', CategoryModel)

产品创造路线的逻辑

  async post(req, res, next) {
        try {
            // Get fields from client
            let { productName, price, preview, color, specs, category } = req.body

            // Looking for a category transferred from a client
            const productCategory = await CategoryModel.find({ name: category })
            console.log(productCategory)

            // Creating product
            const doc = new ProductModel({
                productName,
                price,
                preview,
                color,
                specs,
                category: productCategory._id,
            })

            // Save product
            const product = await doc.save()

            // Returning a response from the server to the client
            return res.json(product)
        } catch (error) {
            console.log(error.message)
        }
    }

以下是我发送到服务器并从服务器接收的内容

Request:
{
    "productName": "Air pods pro",
    "price": 123,
    "preview": "preview",
    "color": "red",
    "specs": {
        "images": ["image1, image2, image3"],
        "memory": 64,
        "ram": 16,
        "diagonal": "diagonal"
    },
    "category": "AirPods"
}

Response:
{
    "productName": "Air pods pro",
    "price": 123,
    "preview": "preview",
    "color": "red",
    "specs": {
        "images": [
            "image1, image2, image3"
        ],
        "memory": 64,
        "ram": 16,
        "diagonal": "diagonal"
    },
    "_id": "6609ad76341da85122e029d0",
    "__v": 0
}

正如您所看到的,响应中没有类别字段,就像在数据库中一样,每个产品中都缺少该字段。而拥有一系列产品的Category集合也未填充

我将在下面附上截图

Mongo Mongo

1 回复 | 直到 1 年前

jQueeny 1 年前

在您的 ProductModel 架构 category 属性具有 name 给它的财产。这表明你想要 类别 成为具有的对象 名称 所有物我认为那不是你的本意。你需要去掉它,这样 类别 只是值为类型的属性 ObjectId .

const ProductModel = new Schema({
    //...
    category: {
        name: String, //< delete this
        type: Schema.Types.ObjectId,
        ref: 'Category',
    },
})

获取 product._id 进入 productCategory.products 数组中,您需要手动将其推送到数组中,如下所示:

const productCategory = await CategoryModel.find({ name: category })
console.log(productCategory)

// Creating product
const doc = new ProductModel({
   productName,
   price,
   preview,
   color,
   specs,
   category: productCategory._id,
})

// Save product
const product = await doc.save()

// Now save product._id into productCategory.products array
productCategory.products.push(product._id);
await productCategory.save();

// Returning a response from the server to the client
return res.json(product)