Why Does My Node js MongoDB Query Throw a TypeError Argument Must Be a String for Custom ObjectID

Question

Can someone exlpain me with the code ans example that Why Does My Node.js MongoDB Query Throw a 'TypeError: Argument Must Be a String' for Custom ObjectID?

Answer 1

The error TypeError: Argument must be a string in a Node.js MongoDB query typically occurs when you attempt to create or use an ObjectID with an invalid or improperly formatted value. MongoDB's ObjectID requires a 24-character hexadecimal string or a 12-byte binary value.

Common Causes and Solutions:

Invalid ObjectID Format:

Ensure the value passed to ObjectID is a 24-character hexadecimal string.

Example:

const { ObjectID } = require('mongodb');

const id = new ObjectID('507f1f77bcf86cd799439011'); // Valid

Undefined or Null Value:

Check if the value being passed to ObjectID is undefined or null.

Example:

const id = req.params.id; // Ensure this is defined

if (!id) {

  throw new Error('ID is required');

}

const objectId = new ObjectID(id);

Non-String Value:

Ensure the value is a string. If it's a number or another type, convert it to a string.

Example:

const id = req.params.id.toString(); // Convert to string

const objectId = new ObjectID(id);

Incorrect ObjectID Import:

Ensure you are importing ObjectID correctly from the mongodb package.

Example:

const { ObjectID } = require('mongodb'); // Correct import

Using Mongoose:

If you're using Mongoose, it automatically converts strings to ObjectID. You may not need to manually create an ObjectID.

Example:

const mongoose = require('mongoose');

const id = req.params.id; // Mongoose will handle the conversion

const result = await Model.findById(id);