BinData()

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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 `###`.
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