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BinData()

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  • Definition
  • Behavior
  • Examples

Creates a binary data object.

BinData has the following syntax:

BinData(<sub_type>,<buffer>)
Parameter
Type
Description
sub_type
integer

The binary type.

Subtype
Description
0
Generic binary subtype
1
Function
2
Byte Array
3
OLD UUID
4
UUID
5
MD5
128
User defined
buffer
string
The buffer object containing binary data, must be a base 64 encoded string value.
Returns:A binary data object.

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.

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)
}

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:

16
← Binary.createFromHexString()