Mongoose how to sort by date which is in array of objects of a field-CodePudding

i want to grab data sorted by its date but the date is not in a field's value, its in the field's value's object's array(if i said it correctly).

here is an example of the data i have:

{
  role: "User",
  fullName: "Verna Pagac",
  username: "dwightkoss95",
  email: "[email protected]",
  orders: [{
    buyerUsername: 'admin',
    boughtAt: 2022-09-20T20:14:59.304Z
  },
  {
    buyerUsername: 'admin',
    boughtAt: 2022-10-30T22:35:35.546Z
  }]
}

after i extracted the orders by the following command, i want to sort them by the boughtAt but how?

const usersWithOrders = await users
        .find({
            orders: { $exists: true, $ne: [] }
        })

const orders = []
usersWithOrders.map((user) => {
        for (i=0 ; i<user.orders.length ; i  ) {
            orders.push(user.orders[i])
        }
    })

i want the newer order to be top.

console.log(orders)

// now it shows the following out put:

/*
[{
    buyerUsername: 'admin',
    boughtAt: 2022-09-20T20:14:59.304Z
  },
  {
    buyerUsername: 'admin',
    boughtAt: 2022-10-30T22:35:35.546Z
  }]
*/

CodePudding user response：

If you want you can sort directly from db using the aggregation framework

db.users.aggregate([
  { $unwind: '$orders' },
  { $sort: { 'orders.boughtAt': -1 } },
  {
    $group: {
      _id: '$_id',
      user: { $first: '$$ROOT' },
      orders: { $push: '$orders' },
    },
  },
])

or if you prefer you can sort in JS

orders.sort((a, b) => b.boughtAt - a.boughtAt)