无法从嵌套数组中提取

Question

I have this query

router.delete('/:_id', async (req, res) => {
  const {_id} = req.params;
  const errors = [];
  console.log(_id);
  await Promise.all([
    // Pon.findOneAndDelete({_id}).catch((e) => {
    //   console.log(e);
    //   errors.push('Something went wrong. Pon was not deleted');
    // }),
    // ^^^^^^^^^ this part worked. Wanted to just test the other query
    User.findOneAndUpdate({_id: req.user._id}, {$pull: {pons: {_id}}}).catch((e) => {
      console.log(1, e);
      errors.push('Something went wrong. Pon reference was not deleted from user');
    }),
  ]);
  if (errors.length > 0) {
    console.log(2, errors);
    res.json({ok: false, errors});
  } else {
    res.json({ok: true});
  }
});

I am just trying to remove an element from user object. Here's the object

{
    "_id": {
        "$oid": "5ea2d8cffe35b93e84f7962b"
    },
    "pons": [
        {
            "$oid": "5ea98b181a2be04ec87aa710" // this is what I want to remove
        }
    ],
    "email": "test@test.tes",
    "password": "$2a$12$VJ0MkcGUs42pikT42qLpyOb0Sd53j9LXH8dY9RdR/GcmUVzJoP8gi",
    "__v": 0
}

This query doesn't throw any errors, catch doesn't catch anything, so I don't know what I'm doing wrong. I tried just doing {pons: _id} instead of {pons: {_id}} but no luck.

The _id is correct. Checked with console.log.

What am I missing?

Answer 1

_id is just a String . If you want to match an ObjectId , you have to wrap it like this mongoose.Types.ObjectId(_id)

const ObjectId = mongoose.Types.ObjectId

User.findOneAndUpdate(
  { _id: ObjectId(req.user._id) },
  { $pull: { pons: ObjectId(_id) } }
)

Since you are querying by _id , you could also use User.findByIdAndUpdate() which will wrap req.user._id with ObjectId for you.

const ObjectId = mongoose.Types.ObjectId

User.findByIdAndUpdate(req.user._id, { $pull: { pons: ObjectId(_id) } })