猫鼬填充新实例

Question

我将Node and Express与Mongoose结合使用，并且试图在其中填充'product'属性

const item = new CartItem({ _pId: id, product: id });

所以我想做的基本上是这样，但它不起作用

   const item = new CartItem({ _pId: id, product: id });

    item.populate({
      path: 'cart.products.product',
      model: 'Product',
      select: '-inStock -_userId -__v',
    });

    this.markModified('cart.products');

    this.cart.products.push(item);
    return this.save();

我也不确定这部分是否是“ this.markModified（'cart.products'）;”是必需的。

这是整个方法

schema.methods.addUpdateRemoveCartItem = function (id, newQuantity) {
  let productsIndex;

  const productIsInCart = this.cart.products.some((el) => {
    productsIndex = this.cart.products.indexOf(el);
    return el._pId._id.equals(id);
  });

  if (productIsInCart) {
    if (newQuantity > 0) {
      this.cart.products[productsIndex].qty = +newQuantity;
    } else if (newQuantity == 0) {
      this.cart.products.splice(productsIndex, 1);
    } else {
      this.cart.products[productsIndex].qty += 1;
    }

    this.markModified('cart.products');
  } else {
    /* doesnt populate */
    const item = new CartItem({ _pId: id, product: id });

    item.populate({
      path: 'cart.products.product',
      model: 'Product',
      select: '-inStock -_userId -__v',
    });

    this.markModified('cart.products');

    this.cart.products.push(item);
    return this.save();
  }

这是模型

const mongoose = require('mongoose');
const CartItem = require('../models/cart.model');
const Product = require('../models/product.model');

const schema = new mongoose.Schema(
  {
    name: {
      type: String,
      trim: true,
      required: true,
      maxLength: 30,
      minlength: 2,
    },
    email: {
      type: String,
      trim: true,
      required: true,
    },
    cart: {
      products: { type: Array, of: CartItem },
      totalQuantity: { type: Number, min: 0, default: 0 },
      totalPrice: { type: Number, min: 0, default: 0 },
    },
  },
  {
    toJSON: { virtuals: true },
    toObject: { virtuals: true },
  }
);

schema.methods.addUpdateRemoveCartItem = function (id, newQuantity) {// specified above}

const User = mongoose.model('User', schema);

module.exports = User;

const mongoose = require('mongoose');

const schema = new mongoose.Schema({
  _id: false,
  _pId: {
    type: mongoose.Schema.Types.ObjectId,
    ref: 'Product',
    trim: true,
    required: true,
  },
  product: {
    type: mongoose.Schema.Types.ObjectId,
    ref: 'Product',
    trim: true,
    required: true,
  },
  qty: {
    type: Number,
    trim: true,
    required: true,
    max: 10000,
    min: 0,
    default: 1,
  },
});

const Cart = mongoose.model('Cart', schema);

module.exports = Cart;