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Esempio di codice

C++

Per scoprire come installare e utilizzare la libreria client per Spanner, consulta la pagina relativa alle librerie client di Spanner.

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void AddIndex(google::cloud::spanner_admin::DatabaseAdminClient client,
              std::string const& project_id, std::string const& instance_id,
              std::string const& database_id) {
  google::cloud::spanner::Database database(project_id, instance_id,
                                            database_id);
  auto metadata =
      client
          .UpdateDatabaseDdl(
              database.FullName(),
              {"CREATE INDEX AlbumsByAlbumTitle ON Albums(AlbumTitle)"})
          .get();
  google::cloud::spanner_testing::LogUpdateDatabaseDdl(  //! TODO(#4758)
      client, database, metadata.status());              //! TODO(#4758)
  if (!metadata) throw std::move(metadata).status();
  std::cout << "`AlbumsByAlbumTitle` Index successfully added, new DDL:\n"
            << metadata->DebugString();
}

C#

Per scoprire come installare e utilizzare la libreria client per Spanner, consulta la pagina relativa alle librerie client di Spanner.

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using Google.Cloud.Spanner.Data;
using System;
using System.Threading.Tasks;

public class AddIndexAsyncSample
{
    public async Task AddIndexAsync(string projectId, string instanceId, string databaseId)
    {
        string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
        string createStatement = "CREATE INDEX AlbumsByAlbumTitle ON Albums(AlbumTitle)";

        using var connection = new SpannerConnection(connectionString);
        using var createCmd = connection.CreateDdlCommand(createStatement);
        await createCmd.ExecuteNonQueryAsync();
        Console.WriteLine("Added the AlbumsByAlbumTitle index.");
    }
}

Go

Per scoprire come installare e utilizzare la libreria client per Spanner, consulta la pagina relativa alle librerie client di Spanner.

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import (
	"context"
	"fmt"
	"io"

	database "cloud.google.com/go/spanner/admin/database/apiv1"
	adminpb "google.golang.org/genproto/googleapis/spanner/admin/database/v1"
)

func addIndex(ctx context.Context, w io.Writer, db string) error {
	adminClient, err := database.NewDatabaseAdminClient(ctx)
	if err != nil {
		return err
	}
	defer adminClient.Close()

	op, err := adminClient.UpdateDatabaseDdl(ctx, &adminpb.UpdateDatabaseDdlRequest{
		Database: db,
		Statements: []string{
			"CREATE INDEX AlbumsByAlbumTitle ON Albums(AlbumTitle)",
		},
	})
	if err != nil {
		return err
	}
	if err := op.Wait(ctx); err != nil {
		return err
	}
	fmt.Fprintf(w, "Added index\n")
	return nil
}

Java

Per scoprire come installare e utilizzare la libreria client per Spanner, consulta la pagina relativa alle librerie client di Spanner.

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static void addIndex(DatabaseAdminClient adminClient, DatabaseId dbId) {
  OperationFuture<Void, UpdateDatabaseDdlMetadata> op =
      adminClient.updateDatabaseDdl(
          dbId.getInstanceId().getInstance(),
          dbId.getDatabase(),
          Arrays.asList("CREATE INDEX AlbumsByAlbumTitle ON Albums(AlbumTitle)"),
          null);
  try {
    // Initiate the request which returns an OperationFuture.
    op.get();
    System.out.println("Added AlbumsByAlbumTitle index");
  } catch (ExecutionException e) {
    // If the operation failed during execution, expose the cause.
    throw (SpannerException) e.getCause();
  } catch (InterruptedException e) {
    // Throw when a thread is waiting, sleeping, or otherwise occupied,
    // and the thread is interrupted, either before or during the activity.
    throw SpannerExceptionFactory.propagateInterrupt(e);
  }
}

Node.js

Per scoprire come installare e utilizzare la libreria client per Spanner, consulta la pagina relativa alle librerie client di Spanner.

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// Imports the Google Cloud client library
const {Spanner} = require('@google-cloud/spanner');

/**
 * TODO(developer): Uncomment the following lines before running the sample.
 */
// const projectId = 'my-project-id';
// const instanceId = 'my-instance';
// const databaseId = 'my-database';

// Creates a client
const spanner = new Spanner({
  projectId: projectId,
});

// Gets a reference to a Cloud Spanner instance and database
const instance = spanner.instance(instanceId);
const database = instance.database(databaseId);

const request = ['CREATE INDEX AlbumsByAlbumTitle ON Albums(AlbumTitle)'];

// Creates a new index in the database
try {
  const [operation] = await database.updateSchema(request);

  console.log('Waiting for operation to complete...');
  await operation.promise();

  console.log('Added the AlbumsByAlbumTitle index.');
} catch (err) {
  console.error('ERROR:', err);
} finally {
  // Close the database when finished.
  database.close();
}

PHP

Per scoprire come installare e utilizzare la libreria client per Spanner, consulta la pagina relativa alle librerie client di Spanner.

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use Google\Cloud\Spanner\SpannerClient;

/**
 * Adds a simple index to the example database.
 * Example:
 * ```
 * create_index($instanceId, $databaseId);
 * ```
 *
 * @param string $instanceId The Spanner instance ID.
 * @param string $databaseId The Spanner database ID.
 */
function create_index(string $instanceId, string $databaseId): void
{
    $spanner = new SpannerClient();
    $instance = $spanner->instance($instanceId);
    $database = $instance->database($databaseId);

    $operation = $database->updateDdl(
        'CREATE INDEX AlbumsByAlbumTitle ON Albums(AlbumTitle)'
    );

    print('Waiting for operation to complete...' . PHP_EOL);
    $operation->pollUntilComplete();

    printf('Added the AlbumsByAlbumTitle index.' . PHP_EOL);
}

Python

Per scoprire come installare e utilizzare la libreria client per Spanner, consulta la pagina relativa alle librerie client di Spanner.

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def add_index(instance_id, database_id):
    """Adds a simple index to the example database."""
    spanner_client = spanner.Client()
    instance = spanner_client.instance(instance_id)
    database = instance.database(database_id)

    operation = database.update_ddl(
        ["CREATE INDEX AlbumsByAlbumTitle ON Albums(AlbumTitle)"]
    )

    print("Waiting for operation to complete...")
    operation.result(OPERATION_TIMEOUT_SECONDS)

    print("Added the AlbumsByAlbumTitle index.")

Ruby

Per scoprire come installare e utilizzare la libreria client per Spanner, consulta la pagina relativa alle librerie client di Spanner.

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# project_id  = "Your Google Cloud project ID"
# instance_id = "Your Spanner instance ID"
# database_id = "Your Spanner database ID"

require "google/cloud/spanner"
require "google/cloud/spanner/admin/database"

database_admin_client = Google::Cloud::Spanner::Admin::Database.database_admin

db_path = database_admin_client.database_path project: project_id,
                                              instance: instance_id,
                                              database: database_id

job = database_admin_client.update_database_ddl database: db_path,
                                                statements: [
                                                  "CREATE INDEX AlbumsByAlbumTitle ON Albums(AlbumTitle)"
                                                ]

puts "Waiting for database update to complete"

job.wait_until_done!

puts "Added the AlbumsByAlbumTitle index"

Passaggi successivi

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