Analyzing and interpreting the BSONTypeError

What does this error mean?

“BSONTypeError:Argument Passed In Must Be a String of 12 Bytes or a String of 24 Hex Characters or an Integer"

Before we dive into knowing what this error means and when it occurs let’s understand what BSON means.

BSON is like a binary version of JSON, a way to represent data. It is similar to JSON because it supports different data types like strings, numbers, Booleans, arrays, and objects. But BSON goes further by adding more types such as dates, binary data, and special types like ObjectID and Decimal128. This allows MongoDB to handle a wider range of data in a more efficient way.

Therefore, when we see the error “BSONTypeError” it means the data provided does not match the expected BSON (Binary JSON) type.

Now let us understand this error

“BSONTypeError: Argument Passed In Must Be a String of 12 Bytes or a String of 24 Hex Characters or an Integer”

You see this error message when the ID you provided is not 12 Bytes String, 24 Hex characters String or a number.

MongoDB uses something called an ObjectID to identify each document in a collection. An ObjectID is a special code made up of 12 bytes, usually shown as a string of 24 letters and numbers. So, when you work with ObjectIDs or perform queries that involve them, it's important to make sure that the ID you provide follows this specific format of 12 bytes or 24 characters in hexadecimal (letters and numbers).

If you try to save or use a value in MongoDB that is not supported or doesn't match what MongoDB expects, you may see a "BSONTypeError" error.

Here are some common situations that can cause this error:

1) Invalid Format: If the ID you provided has a string with fewer or more than 24 characters, or contains non-hexadecimal characters, MongoDB will raise this error.

Wrong:

2.Wrong Data Type: If the ID you provided is not one of three specific data types: 24 byte hex string, 12 byte binary string or a Number.

Wrong:

Correct Format:

In this example, validId represents a valid ID as it follows the following format:

1) It consists of 24 characters, which are all hexadecimal (0-9, A-F).

2) The ID is provided as a string

If you get this error, always check if the ID you have sent from the client-side follows the format discussed in the Correct format.