本文属于机器翻译版本。若本译文内容与英语原文存在差异，则一律以英文原文为准。

# \$1 isoDayOf 周
<a name="isoDayOfWeek"></a>

Amazon DocumentDB 中的`$isoDayOfWeek`运算符以整数值形式返回某一日期的 ISO 一周中的某一天。ISO 周日期系统定义每周从星期一开始，到星期日结束，第 1 周是包含一年中第一个星期四的那一周。

**参数**
+ `expression`：要为其返回 ISO 一周中的某天的日期表达式。

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

以下示例演示如何使用`$isoDayOfWeek`运算符检索一组事件文档的 ISO 一周中的某一天。

**创建示例文档**

```
db.events.insertMany([
  { _id: 1, eventDate: ISODate("2023-04-01T12:00:00Z") },
  { _id: 2, eventDate: ISODate("2023-04-02T12:00:00Z") },
  { _id: 3, eventDate: ISODate("2023-04-03T12:00:00Z") },
  { _id: 4, eventDate: ISODate("2023-04-04T12:00:00Z") },
  { _id: 5, eventDate: ISODate("2023-04-05T12:00:00Z") },
  { _id: 6, eventDate: ISODate("2023-04-06T12:00:00Z") },
  { _id: 7, eventDate: ISODate("2023-04-07T12:00:00Z") }
]);
```

**查询示例**

```
db.events.aggregate([
  { $project: {
    _id: 1,
    eventDate: 1,
    isoDayOfWeek: { $isoDayOfWeek: "$eventDate" }
  }}
]);
```

**输出**

```
[
  { "_id": 1, "eventDate": ISODate("2023-04-01T12:00:00Z"), "isoDayOfWeek": 6 },
  { "_id": 2, "eventDate": ISODate("2023-04-02T12:00:00Z"), "isoDayOfWeek": 7 },
  { "_id": 3, "eventDate": ISODate("2023-04-03T12:00:00Z"), "isoDayOfWeek": 1 },
  { "_id": 4, "eventDate": ISODate("2023-04-04T12:00:00Z"), "isoDayOfWeek": 2 },
  { "_id": 5, "eventDate": ISODate("2023-04-05T12:00:00Z"), "isoDayOfWeek": 3 },
  { "_id": 6, "eventDate": ISODate("2023-04-06T12:00:00Z"), "isoDayOfWeek": 4 },
  { "_id": 7, "eventDate": ISODate("2023-04-07T12:00:00Z"), "isoDayOfWeek": 5 }
]
```

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

要查看使用该`$isoDayOfWeek`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 example() {
  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: {
        _id: 1,
        eventDate: 1,
        isoDayOfWeek: { $isoDayOfWeek: '$eventDate' }
      }
    }
  ]).toArray();

  console.log(result);
  client.close();
}

example();
```

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

```
from pymongo import MongoClient

def example():
    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([
        {
            '$project': {
                '_id': 1,
                'eventDate': 1,
                'isoDayOfWeek': { '$isoDayOfWeek': '$eventDate' }
            }
        }
    ]))

    print(result)
    client.close()

example()
```

------