Create Time Series Collections创建时间序列集合

Prerequisites先决条件

If you have not done so already, you must complete the following prerequisites before you can create a time series collection with a MongoDB Playground:如果您还没有这样做，您必须完成以下先决条件，然后才能使用MongoDB Playground创建时间序列集合：

• Create a connection to a MongoDB deployment.创建到MongoDB部署的连接。
• Activate the connection to the MongoDB deployment.激活到MongoDB部署的连接。

Create a Time Series Collection创建时间序列集合

Once you connect to your deployment using MongoDB for VS code, use the left navigation to:使用MongoDB for VS Code连接到部署后，使用左侧导航：

1. Expand an active connection and hover over the database where you want your collection to exist.展开活动连接，并将鼠标悬停在希望集合所在的数据库上。
2. Click the icon that appears.单击出现的图标。
3. A MongoDB playground automatically opens with a template form to create both regular collections and time series collections.MongoDB演练场会自动打开一个模板表单来创建常规集合和时间序列集合。
4. Delete the regular collection form and uncomment the time series form.删除常规集合表单并取消对时间序列表单的注释。
5. Fill in the provided fields with details for your time series collection.在提供的字段中填写时间序列集合的详细信息。
6. To run the playground, click the Play Button at the top right of the VS code navigation bar.要运行演练场，请单击VS Code导航栏右上角的“播放”按钮。

After running the playground with the time series collection, the left navigation will update the collection icon to identify it is a time series collection.使用时间序列集合运行演练场后，左侧导航将更新集合图标，以确定它是时间序列集合。

Example实例

This example creates a time series collection named weather in the test database.本例在test数据库中创建一个名为weather的时间序列集合。

To use this example, start with a collection template from your MongoDB Playgrounds. 要使用此示例，请从MongoDB Playgrounds中的集合模板开始。Delete the template form for regular collections and keep the template for time series collections found below the regular collection template.删除常规集合的模板表单，并保留在常规集合模板下方的时间序列集合模板。

 use('test');

 db.createCollection(
  "weather",
  {
     timeseries: {
        timeField: "timestamp",
        granularity: "hours"
     }
  }
)

In the example:在示例中：

• use('test') selects the database where the collection is added to.选择要将集合添加到的数据库。
• timeseries specifies fields to create a time series collection.指定用于创建时间序列集合的字段。
  • timeField: "timestamp" names the field that contains the dates in the time series documents. 命名包含时间序列文档中日期的字段。In this case, it is timestamp.在这种情况下，它是timestamp。
  • granularity: "hours" defines the time scale by which the documents are stored.定义存储文档的时间刻度。

When you press the Play Button, MongoDB for VS Code splits your Playground and outputs the following result in the Playground Results.json pane to confirm the creation of the time series collection.当您按下“播放”按钮时，MongoDB for VS Code会分割您的演练场，并在Playground Results.json窗格中输出以下结果，以确认时间序列集合的创建。

{
   "ok": 1
}

The weather collection also appears in your collection list, and is marked with the time series icon.weather集合也会显示在集合列表中，并标有时间序列图标。