Crea database

Creare un database.

Per saperne di più

Per la documentazione dettagliata che include questo esempio di codice, vedi quanto segue:

• Creare e gestire database
• Introduzione a Spanner in C#
• Guida introduttiva a Spanner in C++
• Guida introduttiva a Spanner in Go
• Introduzione a Spanner in Java
• Introduzione a Spanner in Node.js
• Introduzione a Spanner in PHP
• Introduzione a Spanner in Python
• Guida introduttiva a Spanner in Ruby

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 CreateDatabase(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);
  google::spanner::admin::database::v1::CreateDatabaseRequest request;
  request.set_parent(database.instance().FullName());
  request.set_create_statement("CREATE DATABASE `" + database.database_id() +
                               "`");
  request.add_extra_statements(R"""(
      CREATE TABLE Singers (
          SingerId   INT64 NOT NULL,
          FirstName  STRING(1024),
          LastName   STRING(1024),
          SingerInfo BYTES(MAX),
          FullName   STRING(2049)
              AS (ARRAY_TO_STRING([FirstName, LastName], " ")) STORED
      ) PRIMARY KEY (SingerId))""");
  request.add_extra_statements(R"""(
      CREATE TABLE Albums (
          SingerId     INT64 NOT NULL,
          AlbumId      INT64 NOT NULL,
          AlbumTitle   STRING(MAX)
      ) PRIMARY KEY (SingerId, AlbumId),
          INTERLEAVE IN PARENT Singers ON DELETE CASCADE)""");
  auto db = client.CreateDatabase(request).get();
  if (!db) throw std::move(db).status();
  std::cout << "Database " << db->name() << " created.\n";
}

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.Threading.Tasks;

public class CreateDatabaseAsyncSample
{
    public async Task CreateDatabaseAsync(string projectId, string instanceId, string databaseId)
    {
        string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}";

        using var connection = new SpannerConnection(connectionString);
        var createDatabase = $"CREATE DATABASE `{databaseId}`";
        // Define create table statement for table #1.
        var createSingersTable =
        @"CREATE TABLE Singers (
                     SingerId INT64 NOT NULL,
                     FirstName STRING(1024),
                     LastName STRING(1024),
                     ComposerInfo BYTES(MAX),
                     FullName STRING(2048) AS (ARRAY_TO_STRING([FirstName, LastName], "" "")) STORED
                 ) PRIMARY KEY (SingerId)";
        // Define create table statement for table #2.
        var createAlbumsTable =
        @"CREATE TABLE Albums (
                     SingerId INT64 NOT NULL,
                     AlbumId INT64 NOT NULL,
                     AlbumTitle STRING(MAX)
                 ) PRIMARY KEY (SingerId, AlbumId),
                 INTERLEAVE IN PARENT Singers ON DELETE CASCADE";

        using var createDbCommand = connection.CreateDdlCommand(createDatabase, createSingersTable, createAlbumsTable);
        await createDbCommand.ExecuteNonQueryAsync();
    }
}

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"
	"regexp"

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

func createDatabase(ctx context.Context, w io.Writer, db string) error {
	matches := regexp.MustCompile("^(.*)/databases/(.*)$").FindStringSubmatch(db)
	if matches == nil || len(matches) != 3 {
		return fmt.Errorf("Invalid database id %s", db)
	}

	adminClient, err := database.NewDatabaseAdminClient(ctx)
	if err != nil {
		return err
	}
	defer adminClient.Close()

	op, err := adminClient.CreateDatabase(ctx, &adminpb.CreateDatabaseRequest{
		Parent:          matches[1],
		CreateStatement: "CREATE DATABASE `" + matches[2] + "`",
		ExtraStatements: []string{
			`CREATE TABLE Singers (
				SingerId   INT64 NOT NULL,
				FirstName  STRING(1024),
				LastName   STRING(1024),
				SingerInfo BYTES(MAX),
				FullName   STRING(2048) AS (
					ARRAY_TO_STRING([FirstName, LastName], " ")
				) STORED
			) PRIMARY KEY (SingerId)`,
			`CREATE TABLE Albums (
				SingerId     INT64 NOT NULL,
				AlbumId      INT64 NOT NULL,
				AlbumTitle   STRING(MAX)
			) PRIMARY KEY (SingerId, AlbumId),
			INTERLEAVE IN PARENT Singers ON DELETE CASCADE`,
		},
	})
	if err != nil {
		return err
	}
	if _, err := op.Wait(ctx); err != nil {
		return err
	}
	fmt.Fprintf(w, "Created database [%s]\n", db)
	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 createDatabase(DatabaseAdminClient dbAdminClient, DatabaseId id) {
  OperationFuture<Database, CreateDatabaseMetadata> op =
      dbAdminClient.createDatabase(
          id.getInstanceId().getInstance(),
          id.getDatabase(),
          Arrays.asList(
              "CREATE TABLE Singers ("
                  + "  SingerId   INT64 NOT NULL,"
                  + "  FirstName  STRING(1024),"
                  + "  LastName   STRING(1024),"
                  + "  SingerInfo BYTES(MAX),"
                  + "  FullName STRING(2048) AS "
                  + "  (ARRAY_TO_STRING([FirstName, LastName], \" \")) STORED"
                  + ") PRIMARY KEY (SingerId)",
              "CREATE TABLE Albums ("
                  + "  SingerId     INT64 NOT NULL,"
                  + "  AlbumId      INT64 NOT NULL,"
                  + "  AlbumTitle   STRING(MAX)"
                  + ") PRIMARY KEY (SingerId, AlbumId),"
                  + "  INTERLEAVE IN PARENT Singers ON DELETE CASCADE"));
  try {
    // Initiate the request which returns an OperationFuture.
    Database db = op.get();
    System.out.println("Created database [" + db.getId() + "]");
  } 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
const instance = spanner.instance(instanceId);

// Note: Cloud Spanner interprets Node.js numbers as FLOAT64s, so they
// must be converted to strings before being inserted as INT64s
const request = {
  schema: [
    `CREATE TABLE Singers (
      SingerId    INT64 NOT NULL,
      FirstName   STRING(1024),
      LastName    STRING(1024),
      SingerInfo  BYTES(MAX),
      FullName    STRING(2048) AS (ARRAY_TO_STRING([FirstName, LastName], " ")) STORED,
    ) PRIMARY KEY (SingerId)`,
    `CREATE TABLE Albums (
      SingerId    INT64 NOT NULL,
      AlbumId     INT64 NOT NULL,
      AlbumTitle  STRING(MAX)
    ) PRIMARY KEY (SingerId, AlbumId),
    INTERLEAVE IN PARENT Singers ON DELETE CASCADE`,
  ],
};

// Creates a database
const [database, operation] = await instance.createDatabase(
  databaseId,
  request
);

console.log(`Waiting for operation on ${database.id} to complete...`);
await operation.promise();

console.log(`Created database ${databaseId} on instance ${instanceId}.`);

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;

/**
 * Creates a database and tables for sample data.
 * Example:
 * ```
 * create_database($instanceId, $databaseId);
 * ```
 *
 * @param string $instanceId The Spanner instance ID.
 * @param string $databaseId The Spanner database ID.
 */
function create_database(string $instanceId, string $databaseId): void
{
    $spanner = new SpannerClient();
    $instance = $spanner->instance($instanceId);

    if (!$instance->exists()) {
        throw new \LogicException("Instance $instanceId does not exist");
    }

    $operation = $instance->createDatabase($databaseId, ['statements' => [
        'CREATE TABLE Singers (
            SingerId     INT64 NOT NULL,
            FirstName    STRING(1024),
            LastName     STRING(1024),
            SingerInfo   BYTES(MAX),
            FullName     STRING(2048) AS
            (ARRAY_TO_STRING([FirstName, LastName], " ")) STORED
        ) PRIMARY KEY (SingerId)',
        'CREATE TABLE Albums (
            SingerId     INT64 NOT NULL,
            AlbumId      INT64 NOT NULL,
            AlbumTitle   STRING(MAX)
        ) PRIMARY KEY (SingerId, AlbumId),
        INTERLEAVE IN PARENT Singers ON DELETE CASCADE'
    ]]);

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

    printf('Created database %s on instance %s' . PHP_EOL,
        $databaseId, $instanceId);
}

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 create_database(instance_id, database_id):
    """Creates a database and tables for sample data."""
    spanner_client = spanner.Client()
    instance = spanner_client.instance(instance_id)

    database = instance.database(
        database_id,
        ddl_statements=[
            """CREATE TABLE Singers (
            SingerId     INT64 NOT NULL,
            FirstName    STRING(1024),
            LastName     STRING(1024),
            SingerInfo   BYTES(MAX),
            FullName   STRING(2048) AS (
                ARRAY_TO_STRING([FirstName, LastName], " ")
            ) STORED
        ) PRIMARY KEY (SingerId)""",
            """CREATE TABLE Albums (
            SingerId     INT64 NOT NULL,
            AlbumId      INT64 NOT NULL,
            AlbumTitle   STRING(MAX)
        ) PRIMARY KEY (SingerId, AlbumId),
        INTERLEAVE IN PARENT Singers ON DELETE CASCADE""",
        ],
    )

    operation = database.create()

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

    print("Created database {} on instance {}".format(database_id, instance_id))

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

instance_path = database_admin_client.instance_path project: project_id, instance: instance_id

job = database_admin_client.create_database parent: instance_path,
                                            create_statement: "CREATE DATABASE `#{database_id}`",
                                            extra_statements: [
                                              "CREATE TABLE Singers (
      SingerId     INT64 NOT NULL,
      FirstName    STRING(1024),
      LastName     STRING(1024),
      SingerInfo   BYTES(MAX)
    ) PRIMARY KEY (SingerId)",

                                              "CREATE TABLE Albums (
      SingerId     INT64 NOT NULL,
      AlbumId      INT64 NOT NULL,
      AlbumTitle   STRING(MAX)
    ) PRIMARY KEY (SingerId, AlbumId),
    INTERLEAVE IN PARENT Singers ON DELETE CASCADE"
                                            ]

puts "Waiting for create database operation to complete"

job.wait_until_done!

puts "Created database #{database_id} on instance #{instance_id}"

Passaggi successivi

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