BinData()

On this page

Definition

Behavior
Examples

Definition

Creates a binary data object.

BinData has the following syntax:

BinData(<sub_type>,<buffer>)

Parameter	Type	Description
`sub_type`	integer	The binary subtype
`buffer`	string	The buffer object containing binary data. Must be a base 64 encoded string value.

Returns:	A binary data object.

Binary Subtypes

Specify one of the following values for sub_type:

Number	Description
0	Generic binary subtype
1	Function data
2	Binary (old)
3	UUID (old)
4	UUID
5	MD5
6	Encrypted BSON value
7	Compressed time series data New in version 5.2.
8	Sensitive data, such as a key or secret. MongoDB does not log literal values for binary data with subtype 8. Instead, MongoDB logs a placeholder value of `###`.
9	Vector data, which is densely packed arrays of numbers of the same type.
128	Custom data

Behavior

The endianness of your system depends on the architecture of your machine. Numbers in BSON data are always stored as little-endian, if your system is big-endian this means that numeric data is converted between big and little endian.

In the context of the bit-test match expression operators:

BinData values act as bitmasks and are interpreted as though they are arbitrary-length unsigned little-endian numbers. The lowest-addressable byte is always interpreted as the least significant byte. Similarly, the highest-addressable byte in the BinData is always interpreted as the most significant byte.

Examples

Insert a `BinData()` Object

Use the BinData() constructor to create the bdata variable.

var bdata = BinData(0, "gf1UcxdHTJ2HQ/EGQrO7mQ==")

Insert the object into the testbin collection.

db.testbin.insertOne( { _id : 1, bin_data: bdata } )

Query the testbin collection for the inserted document.

db.testbin.find()

You can see the binary buffer stored in the collection.

{
  _id: 1,
  bin_data: Binary(Buffer.from("81fd547317474c9d8743f10642b3bb99", "hex"), 0)
}

Get the Length of `BinData()` Object

Use the BinData() constructor to create the bdata variable.

var bdata = BinData(0, "gf1UcxdHTJ2HQ/EGQrO7mQ==")

Use .length() to return the bit length of the object.

bdata.length()

The returned value is:

Back

Binary.createFromHexString

BSONRegExp