更新到期时间

更新表的到期时间。

包含此代码示例的文档页面

如需查看上下文中使用的代码示例，请参阅以下文档：

代码示例

Go

在尝试此示例之前，请按照《BigQuery 快速入门：使用客户端库》中的 Go 设置说明进行操作。如需了解详情，请参阅 BigQuery Go API 参考文档。

import (
	"context"
	"fmt"
	"time"

	"cloud.google.com/go/bigquery"
)

// updateTableExpiration demonstrates setting the table expiration of a table to a specific point in time
// in the future, at which time it will be deleted.
func updateTableExpiration(projectID, datasetID, tableID string) error {
	// projectID := "my-project-id"
	// datasetID := "mydataset"
	// tableID := "mytable"
	ctx := context.Background()
	client, err := bigquery.NewClient(ctx, projectID)
	if err != nil {
		return fmt.Errorf("bigquery.NewClient: %v", err)
	}
	defer client.Close()

	tableRef := client.Dataset(datasetID).Table(tableID)
	meta, err := tableRef.Metadata(ctx)
	if err != nil {
		return err
	}
	update := bigquery.TableMetadataToUpdate{
		ExpirationTime: time.Now().Add(time.Duration(5*24) * time.Hour), // table expiration in 5 days.
	}
	if _, err = tableRef.Update(ctx, update, meta.ETag); err != nil {
		return err
	}
	return nil
}

Java

试用此示例之前，请按照《BigQuery 快速入门：使用客户端库》中的 Java 设置说明进行操作。如需了解详情，请参阅 BigQuery Java API 参考文档。

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import com.google.cloud.bigquery.BigQuery;
import com.google.cloud.bigquery.BigQueryException;
import com.google.cloud.bigquery.BigQueryOptions;
import com.google.cloud.bigquery.Table;
import java.util.concurrent.TimeUnit;

public class UpdateTableExpiration {

  public static void main(String[] args) {
    // TODO(developer): Replace these variables before running the sample.
    String datasetName = "MY_DATASET_NAME";
    String tableName = "MY_TABLE_NAME";
    // Update table expiration to one day.
    Long newExpiration = TimeUnit.MILLISECONDS.convert(1, TimeUnit.DAYS);
    updateTableExpiration(datasetName, tableName, newExpiration);
  }

  public static void updateTableExpiration(
      String datasetName, String tableName, Long newExpiration) {
    try {
      // Initialize client that will be used to send requests. This client only needs to be created
      // once, and can be reused for multiple requests.
      BigQuery bigquery = BigQueryOptions.getDefaultInstance().getService();

      Table table = bigquery.getTable(datasetName, tableName);
      bigquery.update(table.toBuilder().setExpirationTime(newExpiration).build());

      System.out.println("Table expiration updated successfully to " + newExpiration);
    } catch (BigQueryException e) {
      System.out.println("Table expiration was not updated \n" + e.toString());
    }
  }
}

Node.js

在尝试此示例之前，请按照《BigQuery 快速入门：使用客户端库》中的 Node.js 设置说明进行操作。如需了解详情，请参阅 BigQuery Node.js API 参考文档。

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// Import the Google Cloud client library
const {BigQuery} = require('@google-cloud/bigquery');
const bigquery = new BigQuery();

async function updateTableExpiration() {
  // Updates a table's expiration.

  /**
   * TODO(developer): Uncomment the following lines before running the sample.
   */
  // const datasetId = 'my_dataset', // Existing dataset
  // const tableId = 'my_table', // Existing table
  // const expirationTime = Date.now() + 1000 * 60 * 60 * 24 * 5 // 5 days from current time in ms

  // Retreive current table metadata
  const table = bigquery.dataset(datasetId).table(tableId);
  const [metadata] = await table.getMetadata();

  // Set new table expiration to 5 days from current time
  metadata.expirationTime = expirationTime.toString();
  const [apiResponse] = await table.setMetadata(metadata);

  const newExpirationTime = apiResponse.expirationTime;
  console.log(`${tableId} expiration: ${newExpirationTime}`);
}

Python

在尝试此示例之前，请按照《BigQuery 快速入门：使用客户端库》中的 Python 设置说明进行操作。如需了解详情，请参阅 BigQuery Python API 参考文档。

在 GitHub 上查看反馈

import datetime
import pytz

# from google.cloud import bigquery
# client = bigquery.Client()
# project = client.project
# dataset_ref = bigquery.DatasetReference(project, dataset_id)
# table_ref = dataset_ref.table('my_table')
# table = client.get_table(table_ref)  # API request

assert table.expires is None

# set table to expire 5 days from now
expiration = datetime.datetime.now(pytz.utc) + datetime.timedelta(days=5)
table.expires = expiration
table = client.update_table(table, ["expires"])  # API request

# expiration is stored in milliseconds
margin = datetime.timedelta(microseconds=1000)
assert expiration - margin <= table.expires <= expiration + margin