Load a CSV file to replace a table

Load a CSV file from Cloud Storage, replacing a table.

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For detailed documentation that includes this code sample, see the following:

Code sample

Go

Before trying this sample, follow the Go setup instructions in the BigQuery quickstart using client libraries. For more information, see the BigQuery Go API reference documentation.

To authenticate to BigQuery, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

import (
	"context"
	"fmt"

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

// importCSVTruncate demonstrates loading data from CSV data in Cloud Storage and overwriting/truncating
// data in the existing table.
func importCSVTruncate(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: %w", err)
	}
	defer client.Close()

	gcsRef := bigquery.NewGCSReference("gs://cloud-samples-data/bigquery/us-states/us-states.csv")
	gcsRef.SourceFormat = bigquery.CSV
	gcsRef.AutoDetect = true
	gcsRef.SkipLeadingRows = 1
	loader := client.Dataset(datasetID).Table(tableID).LoaderFrom(gcsRef)
	loader.WriteDisposition = bigquery.WriteTruncate

	job, err := loader.Run(ctx)
	if err != nil {
		return err
	}
	status, err := job.Wait(ctx)
	if err != nil {
		return err
	}

	if status.Err() != nil {
		return fmt.Errorf("job completed with error: %w", status.Err())
	}
	return nil
}

Java

Before trying this sample, follow the Java setup instructions in the BigQuery quickstart using client libraries. For more information, see the BigQuery Java API reference documentation.

To authenticate to BigQuery, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

import com.google.cloud.bigquery.BigQuery;
import com.google.cloud.bigquery.BigQueryException;
import com.google.cloud.bigquery.BigQueryOptions;
import com.google.cloud.bigquery.FormatOptions;
import com.google.cloud.bigquery.Job;
import com.google.cloud.bigquery.JobInfo;
import com.google.cloud.bigquery.JobInfo.WriteDisposition;
import com.google.cloud.bigquery.LoadJobConfiguration;
import com.google.cloud.bigquery.TableId;

// Sample to overwrite the BigQuery table data by loading a CSV file from GCS
public class LoadCsvFromGcsTruncate {

  public static void main(String[] args) throws Exception {
    // TODO(developer): Replace these variables before running the sample.
    String datasetName = "MY_DATASET_NAME";
    String tableName = "MY_TABLE_NAME";
    String sourceUri = "gs://cloud-samples-data/bigquery/us-states/us-states.csv";
    loadCsvFromGcsTruncate(datasetName, tableName, sourceUri);
  }

  public static void loadCsvFromGcsTruncate(String datasetName, String tableName, String sourceUri)
      throws Exception {
    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 tableId = TableId.of(datasetName, tableName);

      LoadJobConfiguration configuration =
          LoadJobConfiguration.builder(tableId, sourceUri)
              .setFormatOptions(FormatOptions.csv())
              // Set the write disposition to overwrite existing table data
              .setWriteDisposition(WriteDisposition.WRITE_TRUNCATE)
              .build();

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

      // Load data from a GCS parquet file into the table
      // Blocks until this load table job completes its execution, either failing or succeeding.
      Job completedJob = loadJob.waitFor();

      // Check for errors
      if (completedJob == null) {
        throw new Exception("Job not executed since it no longer exists.");
      } else if (completedJob.getStatus().getError() != null) {
        // You can also look at queryJob.getStatus().getExecutionErrors() for all
        // errors, not just the latest one.
        throw new Exception(
            "BigQuery was unable to load into the table due to an error: \n"
                + loadJob.getStatus().getError());
      }
      System.out.println("Table is successfully overwritten by CSV file loaded from GCS");
    } catch (BigQueryException | InterruptedException e) {
      System.out.println("Column not added during load append \n" + e.toString());
    }
  }
}

PHP

Before trying this sample, follow the PHP setup instructions in the BigQuery quickstart using client libraries. For more information, see the BigQuery PHP API reference documentation.

To authenticate to BigQuery, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

use Google\Cloud\BigQuery\BigQueryClient;

/**
 * Import data from storage csv with write truncate option.
 *
 * @param string $projectId The project Id of your Google Cloud Project.
 * @param string $datasetId The BigQuery dataset ID.
 * @param string $tableId The BigQuery table ID.
 */
function import_from_storage_csv_truncate(
    string $projectId,
    string $datasetId,
    string $tableId = 'us_states'
): void {
    // instantiate the bigquery table service
    $bigQuery = new BigQueryClient([
      'projectId' => $projectId,
    ]);
    $table = $bigQuery->dataset($datasetId)->table($tableId);

    // create the import job
    $gcsUri = 'gs://cloud-samples-data/bigquery/us-states/us-states.csv';
    $loadConfig = $table->loadFromStorage($gcsUri)->skipLeadingRows(1)->writeDisposition('WRITE_TRUNCATE');
    $job = $table->runJob($loadConfig);

    // check if the job is complete
    $job->reload();
    if (!$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('Data imported successfully' . PHP_EOL);
    }
}

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