复制单个源表

将单个源表复制到给定目标。

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：

管理表

代码示例

C#

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


using Google.Apis.Bigquery.v2.Data;
using Google.Cloud.BigQuery.V2;
using System;

public class BigQueryCopyTable
{
    public void CopyTable(
        string projectId = "your-project-id",
        string destinationDatasetId = "your_dataset_id"
    )
    {
        BigQueryClient client = BigQueryClient.Create(projectId);
        TableReference sourceTableRef = new TableReference()
        {
            TableId = "shakespeare",
            DatasetId = "samples",
            ProjectId = "bigquery-public-data"
        };
        TableReference destinationTableRef = client.GetTableReference(
            destinationDatasetId, "destination_table");
        BigQueryJob job = client.CreateCopyJob(
            sourceTableRef, destinationTableRef)
            .PollUntilCompleted() // Wait for the job to complete.
            .ThrowOnAnyError();

        // Retrieve destination table
        BigQueryTable destinationTable = client.GetTable(destinationTableRef);
        Console.WriteLine(
            $"Copied {destinationTable.Resource.NumRows} rows from table "
            + $"{sourceTableRef.DatasetId}.{sourceTableRef.TableId} "
            + $"to {destinationTable.FullyQualifiedId}."
        );
    }
}

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。

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import (
	"context"
	"fmt"

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

// copyTable demonstrates copying a table from a source to a destination, and
// allowing the copy to overwrite existing data by using truncation.
func copyTable(projectID, datasetID, srcID, dstID string) error {
	// projectID := "my-project-id"
	// datasetID := "mydataset"
	// srcID := "sourcetable"
	// dstID := "destinationtable"
	ctx := context.Background()
	client, err := bigquery.NewClient(ctx, projectID)
	if err != nil {
		return fmt.Errorf("bigquery.NewClient: %v", err)
	}
	defer client.Close()

	dataset := client.Dataset(datasetID)
	copier := dataset.Table(dstID).CopierFrom(dataset.Table(srcID))
	copier.WriteDisposition = bigquery.WriteTruncate
	job, err := copier.Run(ctx)
	if err != nil {
		return err
	}
	status, err := job.Wait(ctx)
	if err != nil {
		return err
	}
	if err := status.Err(); 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.CopyJobConfiguration;
import com.google.cloud.bigquery.Job;
import com.google.cloud.bigquery.JobInfo;
import com.google.cloud.bigquery.TableId;

public class CopyTable {

  public static void main(String[] args) {
    // TODO(developer): Replace these variables before running the sample.
    String destinationDatasetName = "MY_DESTINATION_DATASET_NAME";
    String destinationTableId = "MY_DESTINATION_TABLE_NAME";
    String sourceDatasetName = "MY_SOURCE_DATASET_NAME";
    String sourceTableId = "MY_SOURCE_TABLE_NAME";

    copyTable(sourceDatasetName, sourceTableId, destinationDatasetName, destinationTableId);
  }

  public static void copyTable(
      String sourceDatasetName,
      String sourceTableId,
      String destinationDatasetName,
      String destinationTableId) {
    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();

      TableId sourceTable = TableId.of(sourceDatasetName, sourceTableId);
      TableId destinationTable = TableId.of(destinationDatasetName, destinationTableId);

      // For more information on CopyJobConfiguration see:
      // https://googleapis.dev/java/google-cloud-clients/latest/com/google/cloud/bigquery/JobConfiguration.html
      CopyJobConfiguration configuration =
          CopyJobConfiguration.newBuilder(destinationTable, sourceTable).build();

      // For more information on Job see:
      // https://googleapis.dev/java/google-cloud-clients/latest/index.html?com/google/cloud/bigquery/package-summary.html
      Job job = bigquery.create(JobInfo.of(configuration));

      // Blocks until this job completes its execution, either failing or succeeding.
      Job completedJob = job.waitFor();
      if (completedJob == null) {
        System.out.println("Job not executed since it no longer exists.");
        return;
      } else if (completedJob.getStatus().getError() != null) {
        System.out.println(
            "BigQuery was unable to copy table due to an error: \n" + job.getStatus().getError());
        return;
      }
      System.out.println("Table copied successfully.");
    } catch (BigQueryException | InterruptedException e) {
      System.out.println("Table copying job was interrupted. \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 and create a client
const {BigQuery} = require('@google-cloud/bigquery');
const bigquery = new BigQuery();

async function copyTable() {
  // Copies src_dataset:src_table to dest_dataset:dest_table.

  /**
   * TODO(developer): Uncomment the following lines before running the sample
   */
  // const srcDatasetId = "my_src_dataset";
  // const srcTableId = "my_src_table";
  // const destDatasetId = "my_dest_dataset";
  // const destTableId = "my_dest_table";

  // Copy the table contents into another table
  const [job] = await bigquery
    .dataset(srcDatasetId)
    .table(srcTableId)
    .copy(bigquery.dataset(destDatasetId).table(destTableId));

  console.log(`Job ${job.id} completed.`);

  // Check the job's status for errors
  const errors = job.status.errors;
  if (errors && errors.length > 0) {
    throw errors;
  }
}

PHP

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

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use Google\Cloud\BigQuery\BigQueryClient;
use Google\Cloud\Core\ExponentialBackoff;

/** Uncomment and populate these variables in your code */
// $projectId = 'The Google project ID';
// $datasetId = 'The BigQuery dataset ID';
// $sourceTableId   = 'The BigQuery table ID to copy from';
// $destinationTableId = 'The BigQuery table ID to copy to';

$bigQuery = new BigQueryClient([
    'projectId' => $projectId,
]);
$dataset = $bigQuery->dataset($datasetId);
$sourceTable = $dataset->table($sourceTableId);
$destinationTable = $dataset->table($destinationTableId);
$copyConfig = $sourceTable->copy($destinationTable);
$job = $sourceTable->runJob($copyConfig);

// poll the job until it is complete
$backoff = new ExponentialBackoff(10);
$backoff->execute(function () use ($job) {
    print('Waiting for job to complete' . PHP_EOL);
    $job->reload();
    if (!$job->isComplete()) {
        throw new Exception('Job has not yet completed', 500);
    }
});
// check if the job has errors
if (isset($job->info()['status']['errorResult'])) {
    $error = $job->info()['status']['errorResult']['message'];
    printf('Error running job: %s' . PHP_EOL, $error);
} else {
    print('Table copied successfully' . PHP_EOL);
}

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。

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from google.cloud import bigquery

# Construct a BigQuery client object.
client = bigquery.Client()

# TODO(developer): Set source_table_id to the ID of the original table.
# source_table_id = "your-project.source_dataset.source_table"

# TODO(developer): Set destination_table_id to the ID of the destination table.
# destination_table_id = "your-project.destination_dataset.destination_table"

job = client.copy_table(source_table_id, destination_table_id)
job.result()  # Wait for the job to complete.

print("A copy of the table created.")