Definition定义
Creates an ObjectId from a base64 value.
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
Syntax语法
ObjectId.createFromBase64( <base64String> [ , <subType> ] )
Method Fields方法字段
The method accepts the following fields:该方法接受以下字段：
base64String | "SGVsbG8gV29ybGQh"."SGVsbG8gV29ybGQh"。 | |||||||||||||||||
subType |
|
Examples示例
The following examples show how to add an object identifier to a document using 以下示例显示了如何使用ObjectId.createFromBase64() and how the object identifier appears in the output when retrieved.ObjectId.createFromBase64()将对象标识符添加到文档中，以及检索时对象标识符如何显示在输出中。
Create Collection Containing Document with Base64 Number创建包含Base64数字的文档的集合
The following example creates a collection named 以下示例创建了一个名为objectIdentifierValuesFromBase64:objectIdentifierValuesFromBase64的集合：
db.objectIdentifierValuesFromBase64.insertOne( {
_id: 0,
objectIdentifierValue: ObjectId.createFromBase64( "SGVsbG8gV29ybGQh" )
} )The objectIdentifierValue field contains the object identifier created from the base64 string specified in ObjectId.createFromBase64().objectIdentifierValue字段包含根据ObjectId.createFromBase64()中指定的base64字符串创建的对象标识符。
Retrieve Document from Collection with Object Identifier使用对象标识符从集合中检索文档
The following example retrieves the document:以下示例检索文档：
db.objectIdentifierValuesFromBase64.findOne( { _id: 0 } )Example output:示例输出：
{
_id: 0,
objectIdentifierValue: ObjectId("48656c6c6f20576f726c6421")
}