MongoDB/Mongoose $pull 一个数组中的 Object ，其中 Object 的 _id 匹配

Question

I have this Schema here

Consider the likedTours which is an Array of Objects (Tours) (ignore position 0). I want to pull any Objects where the _id of a Tour matches the critiria.

Adding a new Tour upon liking a tour is okay, but on unlike I don't know how to pull that item out.

Here is my function in the Controller in the Node.JS backend

const unlikeTour = async (req, res) => {
   try {
      TourDB.Tour.findOneAndUpdate(
         { _id: req.params.tourid },
         {
            $pull: { likedUsers: req.userID },
            $inc: { likes: -1 },
         }
      ).exec(async (err, docs) => {
         if (!err) {
            try {
               await UserDB.User.findOneAndUpdate(
                  { _id: req.userID },
                  { $pull: { 'likedTours._id': docs._id } } //Here I need help
               ).exec()
               return res.status(200).send({ successMessage: 'Tour successfully unliked' })
            } catch (err) {
               return res.status(500).send({ errorMessage: 'User not found' })
            }
         } else {
            return res.status(500).send({ errorMessage: 'Tour not found' })
         }
      })
   } catch (err) {
      return res.status(500).send({ errorMessage: err })
   }
}

This method looks for a tour and update it by pulling out the userID and decrement the likes count by -1. And then I try to find in the UserDB that tour in the likedTours and tried to pull but it doesn't not work like that.

Thanks in advance

Answer 1

you can update as

await UserDB.User.findOneAndUpdate(
  { _id: req.userID },
  { $pull: { likedTours: { _id: docs._id } } } //Here I need help
).exec();

reference:https://docs.mongodb.com/manual/reference/operator/update/pull/