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# \$1millisecond
<a name="millisecond"></a>

Amazon DocumentDB 中的`$millisecond`运算符用于提取日期值的毫秒部分。

**参数**

无

## 示例（MongoDB 外壳）
<a name="millisecond-examples"></a>

此示例演示如何使用`$millisecond`运算符提取日期值的毫秒部分。

**创建示例文档**

```
db.events.insert([
  {
    "name": "Event 1",
    "timestamp": ISODate("2023-04-21T10:30:15.123Z")
  },
  {
    "name": "Event 2",
    "timestamp": ISODate("2023-04-21T10:30:15.456Z")
  },
  {
    "name": "Event 3",
    "timestamp": ISODate("2023-04-21T10:30:15.789Z")
  }
])
```

**查询示例**

```
db.events.aggregate([
  {
    $project: {
      name: 1,
      milliseconds: { $millisecond: "$timestamp" }
    }
  }
])
```

**输出**

```
[
  {
    "_id": ObjectId("644332a42054ed1b0d15f0c1"),
    "name": "Event 1",
    "milliseconds": 123
  },
  {
    "_id": ObjectId("644332a42054ed1b0d15f0c2"),
    "name": "Event 2",
    "milliseconds": 456
  },
  {
    "_id": ObjectId("644332a42054ed1b0d15f0c3"),
    "name": "Event 3",
    "milliseconds": 789
  }
]
```

## 代码示例
<a name="millisecond-code"></a>

要查看使用该`$millisecond`命令的代码示例，请选择要使用的语言的选项卡：

------
#### [ Node.js ]

```
const { MongoClient } = require('mongodb');

async function main() {
  const client = await MongoClient.connect('mongodb://<username>:<password>@<cluster-endpoint>:27017/?tls=true&tlsCAFile=global-bundle.pem&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false');
  const db = client.db('test');
  const events = db.collection('events');

  const result = await events.aggregate([
    {
      $project: {
        name: 1,
        milliseconds: { $millisecond: '$timestamp' }
      }
    }
  ]).toArray();

  console.log(result);

  await client.close();
}

main();
```

------
#### [ Python ]

```
from pymongo import MongoClient

client = MongoClient('mongodb://<username>:<password>@<cluster-endpoint>:27017/?tls=true&tlsCAFile=global-bundle.pem&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false')
db = client['test']
events = db['events']

result = list(events.aggregate([
    {
        '$project': {
            'name': 1,
            'milliseconds': { '$millisecond': '$timestamp' }
        }
    }
]))

print(result)

client.close()
```

------