BinData() (mongosh method方法)

Definition定义

Creates a binary data object.创建二进制数据对象。

BinData has the following syntax:具有以下语法：

BinData(<sub_type>,<buffer>)

Parameter参数	Type类型	Description描述
sub_type	integer整数	The binary subtype二进制子类型
buffer	string字符串	The buffer object containing binary data. Must be a base 64 encoded string value.包含二进制数据的缓冲区对象。必须是基64编码字符串值。

Returns:返回	A binary data object.二进制数据对象。

Compatibility兼容性

This method is available in deployments hosted in the following environments:此方法在以下环境中托管的部署中可用：

• MongoDB Atlas: The fully managed service for MongoDB deployments in the cloud：云中MongoDB部署的完全托管服务

• MongoDB Enterprise: The subscription-based, self-managed version of MongoDB：MongoDB的基于订阅的自我管理版本
• MongoDB Community: The source-available, free-to-use, and self-managed version of MongoDB：MongoDB的源代码可用、免费使用和自我管理版本

Behavior行为

The endianness of your system depends on the architecture of your machine. 系统的端序取决于机器的架构。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.BSON数据中的数字始终以小端存储，如果系统是大端，这意味着数字数据在大端和小端之间转换。

In the context of the bit-test match expression operators:在比特测试匹配表达式运算符的上下文中：

• $bitsAnySet
• $bitsAnyClear
• $bitsAllSet
• $bitsAllClear

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. BinData值充当位掩码，并被解释为任意长度的无符号小端数字。最低可寻址字节始终被解释为最低有效字节。Similarly, the highest-addressable byte in the BinData is always interpreted as the most significant byte.同样，BinData中最高可寻址字节始终被解释为最高有效字节。

Examples示例

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

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

db.testbin.find()

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

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

bdata.length()

16