convertShardKeyToHashed（mongosh方法）

说明

convertShardKeyToHashed(<Object>)

Returns the hashed value for the input. The convertShardKeyToHashed() method uses the same hashing function as the hashed index and can be used to see what the hashed value would be for a key.

兼容性

此方法可用于以下环境中托管的部署：

• MongoDB Atlas: The fully managed service for MongoDB deployments in the cloud

• MongoDB Enterprise：基于订阅、自我管理的 MongoDB 版本

• MongoDB Community：源代码可用、免费使用且可自行管理的 MongoDB 版本

例子

Consider a sharded collection that uses a hashed shard key [1]

use test
db.orders.createIndex( { _id: "hashed" } )
sh.shardCollection( "test.orders", { _id : "hashed" } )

如果集合中存在以下文档，则使用_id字段的哈希值来分发该文档：

{
  _id: ObjectId("5b2be413c06d924ab26ff9ca"),
  "item" : "Chocolates",
  "qty" : 25
}

To determine the hashed value of _id field used to distribute the document across the shards, you can use the convertShardKeyToHashed() method:

convertShardKeyToHashed( ObjectId("5b2be413c06d924ab26ff9ca") )