如何在 mongoose/mongodb 和 nodejs 中对对象数组进行排序？

Question

I want to find a brand and then sort the product associated with the brand in ascending and descending order on the basis of price. I tried but it is not changing anything. is it possible with mongoose or what else code i must add?

Controller

exports.getBrandLowtoHighPrice = (req, res, next) => {

    const page = +req.query.page || 1; //convert to number
    let totalItems;
  
    let sessionUser = req.user;
    if (typeof sessionUser == "undefined") {
      sessionUser = "guest";
    }
    Brand.findById(req.params.id)
      .sort({'product.createdAt' : -1})
      .skip((page - 1) * ITEM_PER_PAGE) 
      .limit(ITEM_PER_PAGE)
      .populate({
        path: "product",
        populate: {
          path: "category",
          model: "Category",
        },
        populate: {
          path: "subCategory",
          model: "SubCategory",
        },
        populate: {
          path: "brand",
          model: "Brand",
        },
        populate: {
          path: "rating",
          model: "Rating",
        },
      })
      .then((products) => {
        console.log(products)
        res.render("user/single-brand", {
          categories: req.categories,
          subCategories: req.subCategories,
          bestSeller: req.bestSeller,
          products: products.product,
          brand: req.brand,
          user: sessionUser,
          banner: req.banner,
          brandId: req.params.id,
          currentPage: page,
          hasNextPage: ITEM_PER_PAGE * page < totalItems,
          hasPreviousPage: page > 1,
          nextPage: page + 1,
          previousPage: page - 1,
          lastPage: Math.ceil(totalItems / ITEM_PER_PAGE),
          
        });
      })
      .catch((err) => {
        console.log(err);
      })
  }

Here i have tried sort but not working. My data structure looks like this Data

{
   product:[
     {
      category: [Array],
      subCategory: [Array],
      brand: [Array],
      rating: [],
      sellCount: '1',
      color: [Array],
      size: [Array],
      image: [Array],
      _id: 60f444ace8568b2fec481dcf,
      title: 'nvhjm m',
      description: 'hello',
      price: 200,
      discount: 2,
      quantity: 9,
      feature: false,
      active: true,
      stock: true,
      createdAt: 2021-07-18T15:11:40.047Z,
      updatedAt: 2021-07-20T01:23:06.113Z,
      __v: 0
    }
  ],
  _id: 60e14e4a94e27f3a2c93a26f,
  brand: 'Acer',
  image: 'images\\2021-07-04T05-59-38.028Z-download.png',
  createdAt: 2021-07-04T05:59:38.042Z,
  updatedAt: 2021-07-18T15:11:40.056Z,
  __v: 0
}

I want to sort my value on basis pf product price. Thank you!

Answer 1

This might can help you :

const Brand =  require('../../model/admin/brand')

exports.getBrandLowtoHighPrice = (req, res, next) => {

    const page = +req.query.page || 1; //convert to number
    let totalItems;
  
    let sessionUser = req.user;
    if (typeof sessionUser == "undefined") {
      sessionUser = "guest";
    }
    Brand.findById(req.params.id)
      .sort({'product.createdAt' : -1})
      .skip((page - 1) * ITEM_PER_PAGE) 
      .limit(ITEM_PER_PAGE)
      .populate({
        path: "product",
        populate: {
          path: "category",
          model: "Category",
        },
        populate: {
          path: "subCategory",
          model: "SubCategory",
        },
        populate: {
          path: "brand",
          model: "Brand",
        },
        populate: {
          path: "rating",
          model: "Rating",
        },
        options: { sort: { 'price': 1 } }
      })
      /* .populate({path: 'housingposts', options: { sort: { 'date': -1 } } }) */
      .then((products) => {
        console.log(products)
        res.render("user/single-brand", {
          categories: req.categories,
          subCategories: req.subCategories,
          bestSeller: req.bestSeller,
          products: products.product,
          brand: req.brand,
          user: sessionUser,
          banner: req.banner,
          brandId: req.params.id,
          currentPage: page,
          hasNextPage: ITEM_PER_PAGE * page < totalItems,
          hasPreviousPage: page > 1,
          nextPage: page + 1,
          previousPage: page - 1,
          lastPage: Math.ceil(totalItems / ITEM_PER_PAGE),
          
        });
      })
      .catch((err) => {
        console.log(err);
      })
  }

Answer 2

Check out the $expr, it enables you to compare two field vale together. or checkout the array mql operators it might be of help.