CODEWITHSUNDEEP
node.jsmongodbmongoose
chris_mac
chris_mac

Reputation: 953

Why can't I use $ character at start of Mongoose Schema key

I would like to use a $ in a Mongoose Schema (data is formatted this way from another app), like this:

const mySchema = new mongoose.Schema({
  $meta1: {
   type: String,
   trim: true,
  },
  $meta2: {
    type: String,
    trim: true,
  },
  normalKey3: {
    type: String,
    trim: true,
  }
});

When I attempt this, and run the function (with PUT route):

exports.updateMe = async (req, res) => {
  const xyz = await MySchema.findOneAndUpdate({normalKey3: req.body.normalKey3}, req.body, 
  {
    upsert: true,
    new: true, 
    runValidators: true
  }).exec();
  res.status(200).json(xyz);
};

I get the error below. If I replace the $ with a _ (e.g. _meta1) it works. Is this a Mongoose or Mongo issue? What does $ signify such that it doesn't work?

Error:

Error: Invalid atomic update value for $meta1. Expected an object, received string
[💻]     at castUpdate (/Users/.../node_modules/mongoose/lib/services/query/castUpdate.js:86:13)
[💻]     at model.Query._castUpdate (/Users/.../node_modules/mongoose/lib/query.js:3185:10)
[💻]     at castDoc (/Users/.../node_modules/mongoose/lib/query.js:3212:18)
[💻]     at model.Query.Query._findAndModify (/Users/.../node_modules/mongoose/lib/query.js:2441:19)
[💻]     at model.Query.Query._findOneAndUpdate (/Users/.../node_modules/mongoose/lib/query.js:2163:8)
[💻]     at process.nextTick (/Users/.../node_modules/kareem/index.js:315:33)
[💻]     at process._tickCallback (internal/process/next_tick.js:61:11)

Upvotes: 2

Views: 779

Answers (1)

Mohammed Salah
Mohammed Salah

Reputation: 144

$ is reserved keywords in MongoDB there are limits in MongoDB names

Restrictions on Field Names Field names cannot contain the null character. Top-level field names cannot start with the dollar sign ($) character. Otherwise, starting in MongoDB 3.6, the server permits storage of field names that contain dots (i.e. .) and dollar signs (i.e. $).

you can find more information here Visit https://docs.mongodb.com/manual/reference/limits/

Upvotes: 3

Related Questions