Crea y administra secuencias

En esta página, se describe cómo crear, modificar y descartar una secuencia en Spanner con declaraciones de lenguaje de definición de datos (DDL). También puedes ver cómo usar un en un valor predeterminado para propagar una columna de clave primaria.

Consulta la referencia de sintaxis de DDL de secuencia completa para (Bases de datos de dialectos de GoogleSQL y bases de datos de dialectos de PostgreSQL).

Nota: Para explorar Spanner con una instancia de prueba gratuita de 90 días, consulta Cómo crear una instancia de prueba gratuita de Spanner.

Crea una secuencia

En el siguiente ejemplo de código, se crea una secuencia Seq que se usa en la clave primaria valor predeterminado de la tabla Customers e inserta tres filas nuevas en la Tabla Customers.

GoogleSQL

C++

void CreateSequence(
    google::cloud::spanner_admin::DatabaseAdminClient admin_client,
    google::cloud::spanner::Client 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);
  std::vector<std::string> statements;
  statements.emplace_back(R"""(
      CREATE SEQUENCE Seq
          OPTIONS (sequence_kind = 'bit_reversed_positive')
  )""");
  statements.emplace_back(R"""(
      CREATE TABLE Customers (
          CustomerId INT64 DEFAULT (GET_NEXT_SEQUENCE_VALUE(SEQUENCE Seq)),
          CustomerName STRING(1024)
      ) PRIMARY KEY (CustomerId)
  )""");
  auto metadata =
      admin_client.UpdateDatabaseDdl(database.FullName(), std::move(statements))
          .get();
  if (!metadata) throw std::move(metadata).status();
  std::cout << "Created `Seq` sequence and `Customers` table,"
            << " where the key column `CustomerId`"
            << " uses the sequence as a default value,"
            << " new DDL:\n"
            << metadata->DebugString();
  auto commit = client.Commit(
      [&client](google::cloud::spanner::Transaction txn)
          -> google::cloud::StatusOr<google::cloud::spanner::Mutations> {
        auto sql = google::cloud::spanner::SqlStatement(R"""(
            INSERT INTO Customers (CustomerName)
              VALUES ('Alice'),
                     ('David'),
                     ('Marc')
              THEN RETURN CustomerId
        )""");
        using RowType = std::tuple<std::int64_t>;
        auto rows = client.ExecuteQuery(std::move(txn), std::move(sql));
        // Note: This mutator might be re-run, or its effects discarded, so
        // changing non-transactional state (e.g., by producing output) is,
        // in general, not something to be imitated.
        for (auto& row : google::cloud::spanner::StreamOf<RowType>(rows)) {
          if (!row) return std::move(row).status();
          std::cout << "Inserted customer record with CustomerId: "
                    << std::get<0>(*row) << "\n";
        }
        std::cout << "Number of customer records inserted is: "
                  << rows.RowsModified() << "\n";
        return google::cloud::spanner::Mutations{};
      });
  if (!commit) throw std::move(commit).status();
}

C#

using Google.Cloud.Spanner.Admin.Database.V1;
using Google.Cloud.Spanner.Common.V1;
using Google.Cloud.Spanner.Data;
using System;
using System.Collections.Generic;
using System.Threading.Tasks;

public class CreateSequenceSample
{
    public async Task<List<long>> CreateSequenceAsync(string projectId, string instanceId, string databaseId)
    {
        DatabaseAdminClient databaseAdminClient = DatabaseAdminClient.Create();

        DatabaseName databaseName = DatabaseName.FromProjectInstanceDatabase(projectId, instanceId, databaseId);
        string[] statements =
        {
            "CREATE SEQUENCE Seq OPTIONS (sequence_kind = 'bit_reversed_positive')",
            "CREATE TABLE Customers (CustomerId INT64 DEFAULT (GET_NEXT_SEQUENCE_VALUE(SEQUENCE Seq)), CustomerName STRING(1024)) PRIMARY KEY (CustomerId)"
        };
        var operation = await databaseAdminClient.UpdateDatabaseDdlAsync(databaseName, statements);

        var completedResponse = await operation.PollUntilCompletedAsync();

        if (completedResponse.IsFaulted)
        {
            throw completedResponse.Exception;
        }

        Console.WriteLine("Created Seq sequence and Customers table, where the key column CustomerId uses the sequence as a default value");

        string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
        using var connection = new SpannerConnection(connectionString);
        await connection.OpenAsync();

        using var cmd = connection.CreateDmlCommand(
            @"INSERT INTO Customers (CustomerName) VALUES ('Alice'), ('David'), ('Marc') THEN RETURN CustomerId");

        var reader = await cmd.ExecuteReaderAsync();
        var customerIds = new List<long>();
        while (await reader.ReadAsync())
        {
            var customerId = reader.GetFieldValue<long>("CustomerId");
            Console.WriteLine($"Inserted customer record with CustomerId: {customerId}");
            customerIds.Add(customerId);
        }
        Console.WriteLine($"Number of customer records inserted is: {customerIds.Count}");
        return customerIds;
    }
}

Go

import (
	"context"
	"fmt"
	"io"

	"cloud.google.com/go/spanner"
	database "cloud.google.com/go/spanner/admin/database/apiv1"
	adminpb "cloud.google.com/go/spanner/admin/database/apiv1/databasepb"
	"google.golang.org/api/iterator"
)

func createSequence(w io.Writer, db string) error {
	// db := "projects/my-project/instances/my-instance/databases/my-database"
	ctx := context.Background()
	adminClient, err := database.NewDatabaseAdminClient(ctx)
	if err != nil {
		return err
	}
	defer adminClient.Close()

	// List of DDL statements to be applied to the database.
	// Create a sequence, and then use the sequence as auto generated primary key in Customers table.
	ddl := []string{
		"CREATE SEQUENCE Seq OPTIONS (sequence_kind = 'bit_reversed_positive')",
		"CREATE TABLE Customers (CustomerId INT64 DEFAULT (GET_NEXT_SEQUENCE_VALUE(Sequence Seq)), CustomerName STRING(1024)) PRIMARY KEY (CustomerId)",
	}
	op, err := adminClient.UpdateDatabaseDdl(ctx, &adminpb.UpdateDatabaseDdlRequest{
		Database:   db,
		Statements: ddl,
	})
	if err != nil {
		return err
	}
	// Wait for the UpdateDatabaseDdl operation to finish.
	if err := op.Wait(ctx); err != nil {
		return fmt.Errorf("waiting for bit reverse sequence creation to finish failed: %w", err)
	}
	fmt.Fprintf(w, "Created Seq sequence and Customers table, where the key column CustomerId uses the sequence as a default value\n")

	client, err := spanner.NewClient(ctx, db)
	if err != nil {
		return err
	}
	defer client.Close()

	// Inserts records into the Customers table.
	// The ReadWriteTransaction function returns the commit timestamp and an error.
	// The commit timestamp is ignored in this case.
	_, err = client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error {
		stmt := spanner.Statement{
			SQL: `INSERT INTO Customers (CustomerName) VALUES ('Alice'), ('David'), ('Marc') THEN RETURN CustomerId`,
		}
		iter := txn.Query(ctx, stmt)
		defer iter.Stop()
		for {
			row, err := iter.Next()
			if err == iterator.Done {
				break
			}
			if err != nil {
				return err
			}
			var customerId int64
			if err := row.Columns(&customerId); err != nil {
				return err
			}
			fmt.Fprintf(w, "Inserted customer record with CustomerId: %d\n", customerId)
		}
		fmt.Fprintf(w, "Number of customer records inserted is: %d\n", iter.RowCount)
		return nil
	})
	return err
}

Java

import com.google.cloud.spanner.DatabaseClient;
import com.google.cloud.spanner.DatabaseId;
import com.google.cloud.spanner.ResultSet;
import com.google.cloud.spanner.Spanner;
import com.google.cloud.spanner.SpannerExceptionFactory;
import com.google.cloud.spanner.SpannerOptions;
import com.google.cloud.spanner.Statement;
import com.google.cloud.spanner.admin.database.v1.DatabaseAdminClient;
import com.google.common.collect.ImmutableList;
import com.google.spanner.admin.database.v1.DatabaseName;
import java.util.Objects;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

public class CreateSequenceSample {

  static void createSequence() {
    // TODO(developer): Replace these variables before running the sample.
    final String projectId = "my-project";
    final String instanceId = "my-instance";
    final String databaseId = "my-database";
    createSequence(projectId, instanceId, databaseId);
  }

  static void createSequence(String projectId, String instanceId, String databaseId) {

    try (Spanner spanner =
        SpannerOptions.newBuilder().setProjectId(projectId).build().getService();
        DatabaseAdminClient databaseAdminClient = spanner.createDatabaseAdminClient()) {
      databaseAdminClient
          .updateDatabaseDdlAsync(
              DatabaseName.of(projectId, instanceId, databaseId),
              ImmutableList.of(
                  "CREATE SEQUENCE Seq OPTIONS (sequence_kind = 'bit_reversed_positive')",
                  "CREATE TABLE Customers (CustomerId INT64 DEFAULT "
                      + "(GET_NEXT_SEQUENCE_VALUE(SEQUENCE Seq)), CustomerName STRING(1024)) "
                      + "PRIMARY KEY (CustomerId)"))
          .get(5, TimeUnit.MINUTES);

      System.out.println(
          "Created Seq sequence and Customers table, where the key column CustomerId "
              + "uses the sequence as a default value");

      final DatabaseClient dbClient =
          spanner.getDatabaseClient(DatabaseId.of(projectId, instanceId, databaseId));

      Long insertCount =
          dbClient
              .readWriteTransaction()
              .run(
                  transaction -> {
                    try (ResultSet rs =
                        transaction.executeQuery(
                            Statement.of(
                                "INSERT INTO Customers (CustomerName) VALUES "
                                    + "('Alice'), ('David'), ('Marc') THEN RETURN CustomerId"))) {
                      while (rs.next()) {
                        System.out.printf(
                            "Inserted customer record with CustomerId: %d\n", rs.getLong(0));
                      }
                      return Objects.requireNonNull(rs.getStats()).getRowCountExact();
                    }
                  });
      System.out.printf("Number of customer records inserted is: %d\n", insertCount);
    } catch (ExecutionException e) {
      // If the operation failed during execution, expose the cause.
      throw SpannerExceptionFactory.asSpannerException(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);
    } catch (TimeoutException e) {
      // If the operation timed out propagate the timeout
      throw SpannerExceptionFactory.propagateTimeout(e);
    }
  }
}

Nota: Las muestras de código de interfaz de la biblioteca cliente anterior para Java se archivan en GitHub.

Node.js

// 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,
});

async function createSequence(instanceId, databaseId) {
  // Gets a reference to a Cloud Spanner Database Admin Client object
  const databaseAdminClient = spanner.getDatabaseAdminClient();

  const request = [
    "CREATE SEQUENCE Seq OPTIONS (sequence_kind = 'bit_reversed_positive')",
    'CREATE TABLE Customers (CustomerId INT64 DEFAULT (GET_NEXT_SEQUENCE_VALUE(Sequence Seq)), CustomerName STRING(1024)) PRIMARY KEY (CustomerId)',
  ];

  // Creates a new table with sequence
  try {
    const [operation] = await databaseAdminClient.updateDatabaseDdl({
      database: databaseAdminClient.databasePath(
        projectId,
        instanceId,
        databaseId
      ),
      statements: request,
    });

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

    console.log(
      'Created Seq sequence and Customers table, where the key column CustomerId uses the sequence as a default value.'
    );
  } catch (err) {
    console.error('ERROR:', err);
  }

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

  database.runTransaction(async (err, transaction) => {
    if (err) {
      console.error(err);
      return;
    }
    try {
      const [rows, stats] = await transaction.run({
        sql: "INSERT INTO Customers (CustomerName) VALUES ('Alice'), ('David'), ('Marc') THEN RETURN CustomerId",
      });

      rows.forEach(row => {
        console.log(
          `Inserted customer record with CustomerId: ${
            row.toJSON({wrapNumbers: true}).CustomerId.value
          }`
        );
      });

      const rowCount = Math.floor(stats[stats.rowCount]);
      console.log(`Number of customer records inserted is: ${rowCount}`);

      await transaction.commit();
    } catch (err) {
      console.error('ERROR:', err);
    } finally {
      // Close the database when finished.
      await database.close();
    }
  });
}
await createSequence(instanceId, databaseId);

Nota: Las muestras de código de interfaz de la biblioteca cliente anterior para Node.js se archivan en GitHub.

PHP

use Google\Cloud\Spanner\Admin\Database\V1\Client\DatabaseAdminClient;
use Google\Cloud\Spanner\Admin\Database\V1\UpdateDatabaseDdlRequest;
use Google\Cloud\Spanner\SpannerClient;
use Google\Cloud\Spanner\Result;

/**
 * Creates a sequence.
 *
 * Example:
 * ```
 * create_sequence($projectId, $instanceId, $databaseId);
 * ```
 *
 * @param string $projectId The Google Cloud project ID.
 * @param string $instanceId The Spanner instance ID.
 * @param string $databaseId The Spanner database ID.
 */
function create_sequence(string $projectId, string $instanceId, string $databaseId): void
{
    $databaseAdminClient = new DatabaseAdminClient();
    $spanner = new SpannerClient();

    $instance = $spanner->instance($instanceId);
    $database = $instance->database($databaseId);
    $databaseName = DatabaseAdminClient::databaseName($projectId, $instanceId, $databaseId);

    $request = new UpdateDatabaseDdlRequest([
        'database' => $databaseName,
        'statements' => [
            "CREATE SEQUENCE Seq OPTIONS (sequence_kind = 'bit_reversed_positive')",
            'CREATE TABLE Customers (CustomerId INT64 DEFAULT (GET_NEXT_SEQUENCE_VALUE(' .
            'Sequence Seq)), CustomerName STRING(1024)) PRIMARY KEY (CustomerId)'
        ]
    ]);

    $operation = $databaseAdminClient->updateDatabaseDdl($request);

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

    printf(
        'Created Seq sequence and Customers table, where ' .
        'the key column CustomerId uses the sequence as a default value' .
        PHP_EOL
    );

    $transaction = $database->transaction();
    $res = $transaction->execute(
        'INSERT INTO Customers (CustomerName) VALUES ' .
        "('Alice'), ('David'), ('Marc') THEN RETURN CustomerId"
    );
    $rows = $res->rows(Result::RETURN_ASSOCIATIVE);

    foreach ($rows as $row) {
        printf('Inserted customer record with CustomerId: %d %s',
            $row['CustomerId'],
            PHP_EOL
        );
    }
    $transaction->commit();

    printf(sprintf(
        'Number of customer records inserted is: %d %s',
        $res->stats()['rowCountExact'],
        PHP_EOL
    ));
}

Nota: Las muestras de código de interfaz de la biblioteca cliente anterior para PHP están archivadas en GitHub.

Python

def create_sequence(instance_id, database_id):
    """Creates the Sequence and insert data"""

    from google.cloud.spanner_admin_database_v1.types import \
        spanner_database_admin

    spanner_client = spanner.Client()
    database_admin_api = spanner_client.database_admin_api

    request = spanner_database_admin.UpdateDatabaseDdlRequest(
        database=database_admin_api.database_path(
            spanner_client.project, instance_id, database_id
        ),
        statements=[
            "CREATE SEQUENCE Seq OPTIONS (sequence_kind = 'bit_reversed_positive')",
            """CREATE TABLE Customers (
            CustomerId     INT64 DEFAULT (GET_NEXT_SEQUENCE_VALUE(Sequence Seq)),
            CustomerName      STRING(1024)
            ) PRIMARY KEY (CustomerId)""",
        ],
    )

    operation = database_admin_api.update_database_ddl(request)

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

    print(
        "Created Seq sequence and Customers table, where the key column CustomerId uses the sequence as a default value on database {} on instance {}".format(
            database_id, instance_id
        )
    )

    def insert_customers(transaction):
        results = transaction.execute_sql(
            "INSERT INTO Customers (CustomerName) VALUES "
            "('Alice'), "
            "('David'), "
            "('Marc') "
            "THEN RETURN CustomerId"
        )
        for result in results:
            print("Inserted customer record with Customer Id: {}".format(*result))
        print(
            "Number of customer records inserted is {}".format(
                results.stats.row_count_exact
            )
        )

    instance = spanner_client.instance(instance_id)
    database = instance.database(database_id)

    database.run_in_transaction(insert_customers)

Nota: Las muestras de código de la interfaz de la biblioteca cliente anterior para Python se archivan en GitHub:

Ruby

require "google/cloud/spanner"

##
# This is a snippet for showcasing how to create a sequence.
#
# @param project_id  [String] The ID of the Google Cloud project.
# @param instance_id [String] The ID of the spanner instance.
# @param database_id [String] The ID of the database.
#
def spanner_create_sequence project_id:, instance_id:, database_id:
  db_admin_client = Google::Cloud::Spanner::Admin::Database.database_admin

  database_path = db_admin_client.database_path project: project_id,
                                                instance: instance_id,
                                                database: database_id


  job = db_admin_client.update_database_ddl database: database_path, statements: [
    "CREATE SEQUENCE Seq OPTIONS (sequence_kind = 'bit_reversed_positive')",
    "CREATE TABLE Customers (CustomerId INT64 DEFAULT (GET_NEXT_SEQUENCE_VALUE(Sequence Seq)), CustomerName STRING(1024)) PRIMARY KEY (CustomerId)"
  ]

  puts "Waiting for operation to complete..."
  job.wait_until_done!
  puts "Created Seq sequence and Customers table, where the key column CustomerId uses the sequence as a default value"
end

PostgreSQL

C++

void CreateSequence(
    google::cloud::spanner_admin::DatabaseAdminClient admin_client,
    google::cloud::spanner::Database const& database,
    google::cloud::spanner::Client client) {
  std::vector<std::string> statements;
  statements.emplace_back(R"""(
      CREATE SEQUENCE Seq BIT_REVERSED_POSITIVE
  )""");
  statements.emplace_back(R"""(
      CREATE TABLE Customers (
          CustomerId    BIGINT DEFAULT NEXTVAL('Seq'),
          CustomerName  CHARACTER VARYING(1024),
          PRIMARY KEY (CustomerId)
      )
  )""");
  auto metadata =
      admin_client.UpdateDatabaseDdl(database.FullName(), std::move(statements))
          .get();
  if (!metadata) throw std::move(metadata).status();
  std::cout << "Created `Seq` sequence and `Customers` table,"
            << " where the key column `CustomerId`"
            << " uses the sequence as a default value,"
            << " new DDL:\n"
            << metadata->DebugString();
  auto commit = client.Commit(
      [&client](google::cloud::spanner::Transaction txn)
          -> google::cloud::StatusOr<google::cloud::spanner::Mutations> {
        auto sql = google::cloud::spanner::SqlStatement(R"""(
            INSERT INTO Customers (CustomerName)
                VALUES ('Alice'),
                       ('David'),
                       ('Marc')
                RETURNING CustomerId
        )""");
        using RowType = std::tuple<std::int64_t>;
        auto rows = client.ExecuteQuery(std::move(txn), std::move(sql));
        // Note: This mutator might be re-run, or its effects discarded, so
        // changing non-transactional state (e.g., by producing output) is,
        // in general, not something to be imitated.
        for (auto& row : google::cloud::spanner::StreamOf<RowType>(rows)) {
          if (!row) return std::move(row).status();
          std::cout << "Inserted customer record with CustomerId: "
                    << std::get<0>(*row) << "\n";
        }
        std::cout << "Number of customer records inserted is: "
                  << rows.RowsModified() << "\n";
        return google::cloud::spanner::Mutations{};
      });
  if (!commit) throw std::move(commit).status();
}

C#

using Google.Cloud.Spanner.Common.V1;
using System.Threading.Tasks;
using System;
using Google.Cloud.Spanner.Admin.Database.V1;
using Google.Cloud.Spanner.Data;
using System.Collections.Generic;

public class CreateSequencePostgresqlSample
{
    public async Task<List<long>> CreateSequencePostgresqlSampleAsync(string projectId, string instanceId, string databaseId)
    {
        DatabaseAdminClient databaseAdminClient = DatabaseAdminClient.Create();

        DatabaseName databaseName = DatabaseName.FromProjectInstanceDatabase(projectId, instanceId, databaseId);
        string[] statements =
        {
            "CREATE SEQUENCE Seq BIT_REVERSED_POSITIVE ;",
            "CREATE TABLE Customers (CustomerId BIGINT DEFAULT nextval('Seq'), CustomerName character varying(1024), PRIMARY KEY (CustomerId))"
        };
        var operation = await databaseAdminClient.UpdateDatabaseDdlAsync(databaseName, statements);

        var completedResponse = await operation.PollUntilCompletedAsync();
        if (completedResponse.IsFaulted)
        {
            throw completedResponse.Exception;
        }

        Console.WriteLine("Created Seq sequence and Customers table, where the key column CustomerId uses the sequence as a default value");

        string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
        using var connection = new SpannerConnection(connectionString);
        await connection.OpenAsync();

        using var cmd = connection.CreateDmlCommand(
            @"INSERT INTO Customers (CustomerName) VALUES ('Alice'), ('David'), ('Marc') RETURNING CustomerId");

        var reader = await cmd.ExecuteReaderAsync();
        var customerIds = new List<long>();
        while (await reader.ReadAsync())
        {
            var customerId = reader.GetFieldValue<long>("customerid");
            Console.WriteLine($"Inserted customer record with CustomerId: {customerId}");
            customerIds.Add(customerId);
        }
        Console.WriteLine($"Number of customer records inserted is: {customerIds.Count}");
        return customerIds;
    }
}

Go

import (
	"context"
	"fmt"
	"io"

	"cloud.google.com/go/spanner"
	database "cloud.google.com/go/spanner/admin/database/apiv1"
	adminpb "cloud.google.com/go/spanner/admin/database/apiv1/databasepb"
	"google.golang.org/api/iterator"
)

func pgCreateSequence(w io.Writer, db string) error {
	// db := "projects/my-project/instances/my-instance/databases/my-database"
	ctx := context.Background()
	adminClient, err := database.NewDatabaseAdminClient(ctx)
	if err != nil {
		return err
	}
	defer adminClient.Close()

	// List of DDL statements to be applied to the database.
	// Create a sequence, and then use the sequence as auto generated primary key in Customers table.
	ddl := []string{
		"CREATE SEQUENCE Seq BIT_REVERSED_POSITIVE",
		"CREATE TABLE Customers (CustomerId BIGINT DEFAULT nextval('Seq'), CustomerName character varying(1024), PRIMARY KEY (CustomerId))",
	}
	op, err := adminClient.UpdateDatabaseDdl(ctx, &adminpb.UpdateDatabaseDdlRequest{
		Database:   db,
		Statements: ddl,
	})
	if err != nil {
		return err
	}
	// Wait for the UpdateDatabaseDdl operation to finish.
	if err := op.Wait(ctx); err != nil {
		return fmt.Errorf("waiting for bit reverse sequence creation to finish failed: %w", err)
	}
	fmt.Fprintf(w, "Created Seq sequence and Customers table, where its key column CustomerId uses the sequence as a default value\n")

	client, err := spanner.NewClient(ctx, db)
	if err != nil {
		return err
	}
	defer client.Close()

	// Inserts records into the Customers table.
	// The ReadWriteTransaction function returns the commit timestamp and an error.
	// The commit timestamp is ignored in this case.
	_, err = client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error {
		stmt := spanner.Statement{
			SQL: `INSERT INTO Customers (CustomerName) VALUES ('Alice'), ('David'), ('Marc') RETURNING CustomerId`,
		}
		iter := txn.Query(ctx, stmt)
		defer iter.Stop()
		for {
			row, err := iter.Next()
			if err == iterator.Done {
				break
			}
			if err != nil {
				return err
			}
			var customerId int64
			if err := row.Columns(&customerId); err != nil {
				return err
			}
			fmt.Fprintf(w, "Inserted customer record with CustomerId: %d\n", customerId)
		}
		fmt.Fprintf(w, "Number of customer records inserted is: %d\n", iter.RowCount)
		return nil
	})
	return err
}

Java

import com.google.cloud.spanner.DatabaseClient;
import com.google.cloud.spanner.DatabaseId;
import com.google.cloud.spanner.ResultSet;
import com.google.cloud.spanner.Spanner;
import com.google.cloud.spanner.SpannerExceptionFactory;
import com.google.cloud.spanner.SpannerOptions;
import com.google.cloud.spanner.Statement;
import com.google.cloud.spanner.admin.database.v1.DatabaseAdminClient;
import com.google.common.collect.ImmutableList;
import com.google.spanner.admin.database.v1.DatabaseName;
import java.util.Objects;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

public class PgCreateSequenceSample {

  static void pgCreateSequence() {
    // TODO(developer): Replace these variables before running the sample.
    final String projectId = "my-project";
    final String instanceId = "my-instance";
    final String databaseId = "my-database";
    pgCreateSequence(projectId, instanceId, databaseId);
  }

  static void pgCreateSequence(String projectId, String instanceId, String databaseId) {
    try (Spanner spanner =
        SpannerOptions.newBuilder().setProjectId(projectId).build().getService();
        DatabaseAdminClient databaseAdminClient = spanner.createDatabaseAdminClient()) {
      databaseAdminClient
          .updateDatabaseDdlAsync(DatabaseName.of(projectId, instanceId, databaseId).toString(),
              ImmutableList.of(
                  "CREATE SEQUENCE Seq BIT_REVERSED_POSITIVE;",
                  "CREATE TABLE Customers (CustomerId BIGINT DEFAULT nextval('Seq'), "
                      + "CustomerName character varying(1024), PRIMARY KEY (CustomerId))"))
          .get(5, TimeUnit.MINUTES);

      System.out.println(
          "Created Seq sequence and Customers table, where the key column "
              + "CustomerId uses the sequence as a default value");

      final DatabaseClient dbClient =
          spanner.getDatabaseClient(DatabaseId.of(projectId, instanceId, databaseId));

      Long insertCount =
          dbClient
              .readWriteTransaction()
              .run(
                  transaction -> {
                    try (ResultSet rs =
                        transaction.executeQuery(
                            Statement.of(
                                "INSERT INTO Customers (CustomerName) VALUES "
                                    + "('Alice'), ('David'), ('Marc') RETURNING CustomerId"))) {
                      while (rs.next()) {
                        System.out.printf(
                            "Inserted customer record with CustomerId: %d\n", rs.getLong(0));
                      }
                      return Objects.requireNonNull(rs.getStats()).getRowCountExact();
                    }
                  });
      System.out.printf("Number of customer records inserted is: %d\n", insertCount);
    } catch (ExecutionException e) {
      // If the operation failed during execution, expose the cause.
      throw SpannerExceptionFactory.asSpannerException(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);
    } catch (TimeoutException e) {
      // If the operation timed out propagate the timeout
      throw SpannerExceptionFactory.propagateTimeout(e);
    }
  }
}

Nota: Las muestras de código de interfaz de la biblioteca cliente anterior para Java se archivan en GitHub.

Node.js

// 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,
});

async function createSequence(instanceId, databaseId) {
  // Gets a reference to a Cloud Spanner Database Admin Client object
  const databaseAdminClient = spanner.getDatabaseAdminClient();

  const request = [
    'CREATE SEQUENCE Seq BIT_REVERSED_POSITIVE',
    "CREATE TABLE Customers (CustomerId BIGINT DEFAULT nextval('Seq'), CustomerName character varying(1024), PRIMARY KEY (CustomerId))",
  ];

  // Creates a new table with sequence
  try {
    const [operation] = await databaseAdminClient.updateDatabaseDdl({
      database: databaseAdminClient.databasePath(
        projectId,
        instanceId,
        databaseId
      ),
      statements: request,
    });

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

    console.log(
      'Created Seq sequence and Customers table, where the key column CustomerId uses the sequence as a default value'
    );
  } catch (err) {
    console.error('ERROR:', err);
  }

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

  database.runTransaction(async (err, transaction) => {
    if (err) {
      console.error(err);
      return;
    }
    try {
      const [rows, stats] = await transaction.run({
        sql: "INSERT INTO Customers (CustomerName) VALUES ('Alice'), ('David'), ('Marc') RETURNING CustomerId",
      });

      rows.forEach(row => {
        console.log(
          `Inserted customer record with CustomerId: ${
            row.toJSON({wrapNumbers: true}).customerid.value
          }`
        );
      });

      const rowCount = Math.floor(stats[stats.rowCount]);
      console.log(`Number of customer records inserted is: ${rowCount}`);

      await transaction.commit();
    } catch (err) {
      console.error('ERROR:', err);
    } finally {
      // Close the spanner client when finished.
      // The databaseAdminClient does not require explicit closure. The closure of the Spanner client will automatically close the databaseAdminClient.
      spanner.close();
    }
  });
}
await createSequence(instanceId, databaseId);

Nota: Las muestras de código de la interfaz de la biblioteca cliente anterior para Node.js se archivan en GitHub:

PHP

use Google\Cloud\Spanner\Admin\Database\V1\Client\DatabaseAdminClient;
use Google\Cloud\Spanner\Admin\Database\V1\UpdateDatabaseDdlRequest;
use Google\Cloud\Spanner\SpannerClient;
use Google\Cloud\Spanner\Result;

/**
 * Creates a sequence.
 * Example:
 * ```
 * pg_create_sequence($projectId, $instanceId, $databaseId);
 * ```
 *
 * @param string $projectId The Google Cloud Project ID.
 * @param string $instanceId The Spanner instance ID.
 * @param string $databaseId The Spanner database ID.
 */
function pg_create_sequence(
    string $projectId,
    string $instanceId,
    string $databaseId
): void {
    $databaseAdminClient = new DatabaseAdminClient();
    $spanner = new SpannerClient();
    $instance = $spanner->instance($instanceId);
    $database = $instance->database($databaseId);
    $transaction = $database->transaction();
    $operation = $databaseAdminClient->updateDatabaseDdl(new UpdateDatabaseDdlRequest([
        'database' => DatabaseAdminClient::databaseName($projectId, $instanceId, $databaseId),
        'statements' => [
            'CREATE SEQUENCE Seq BIT_REVERSED_POSITIVE',
            "CREATE TABLE Customers (
            CustomerId           BIGINT DEFAULT nextval('Seq'), 
            CustomerName         CHARACTER VARYING(1024), 
            PRIMARY KEY (CustomerId))"
        ]
    ]));

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

    printf(
        'Created Seq sequence and Customers table, where ' .
        'the key column CustomerId uses the sequence as a default value' .
        PHP_EOL
    );

    $res = $transaction->execute(
        'INSERT INTO Customers (CustomerName) VALUES ' .
        "('Alice'), ('David'), ('Marc') RETURNING CustomerId"
    );
    $rows = $res->rows(Result::RETURN_ASSOCIATIVE);

    foreach ($rows as $row) {
        printf('Inserted customer record with CustomerId: %d %s',
            $row['customerid'],
            PHP_EOL
        );
    }
    $transaction->commit();

    printf(sprintf(
        'Number of customer records inserted is: %d %s',
        $res->stats()['rowCountExact'],
        PHP_EOL
    ));
}

Nota: Las muestras de código de la interfaz de la biblioteca cliente anterior para PHP se archivan en GitHub:

Python

def create_sequence(instance_id, database_id):
    """Creates the Sequence and insert data"""

    from google.cloud.spanner_admin_database_v1.types import \
        spanner_database_admin

    spanner_client = spanner.Client()
    database_admin_api = spanner_client.database_admin_api

    request = spanner_database_admin.UpdateDatabaseDdlRequest(
        database=database_admin_api.database_path(
            spanner_client.project, instance_id, database_id
        ),
        statements=[
            "CREATE SEQUENCE Seq BIT_REVERSED_POSITIVE",
            """CREATE TABLE Customers (
        CustomerId  BIGINT DEFAULT nextval('Seq'),
        CustomerName  character varying(1024),
        PRIMARY KEY (CustomerId)
        )""",
        ],
    )
    operation = database_admin_api.update_database_ddl(request)
    print("Waiting for operation to complete...")
    operation.result(OPERATION_TIMEOUT_SECONDS)

    print(
        "Created Seq sequence and Customers table, where the key column CustomerId uses the sequence as a default value on database {} on instance {}".format(
            database_id, instance_id
        )
    )

    def insert_customers(transaction):
        results = transaction.execute_sql(
            "INSERT INTO Customers (CustomerName) VALUES "
            "('Alice'), "
            "('David'), "
            "('Marc') "
            "RETURNING CustomerId"
        )
        for result in results:
            print("Inserted customer record with Customer Id: {}".format(*result))
        print(
            "Number of customer records inserted is {}".format(
                results.stats.row_count_exact
            )
        )

    instance = spanner_client.instance(instance_id)
    database = instance.database(database_id)

    database.run_in_transaction(insert_customers)

Nota: Las muestras de código de la interfaz de la biblioteca cliente anterior para Python se archivan en GitHub:

Ruby

require "google/cloud/spanner"

##
# This is a snippet for showcasing how to create a sequence using postgresql.
#
# @param project_id  [String] The ID of the Google Cloud project.
# @param instance_id [String] The ID of the spanner instance.
# @param database_id [String] The ID of the database.
#
def spanner_postgresql_create_sequence project_id:, instance_id:, database_id:
  db_admin_client = Google::Cloud::Spanner::Admin::Database.database_admin

  database_path = db_admin_client.database_path project: project_id,
                                                instance: instance_id,
                                                database: database_id


  job = db_admin_client.update_database_ddl database: database_path, statements: [
    "CREATE SEQUENCE Seq BIT_REVERSED_POSITIVE",
    "CREATE TABLE Customers (CustomerId BIGINT DEFAULT nextval('Seq'), CustomerName character varying(1024), PRIMARY KEY (CustomerId))"
  ]

  puts "Waiting for operation to complete..."
  job.wait_until_done!
  puts "Created Seq sequence and Customers table, where its key column CustomerId uses the sequence as a default value"
end

Modificar una secuencia

En el siguiente ejemplo de código, se altera la secuencia Seq para omitir un rango de valores de 1,000 a 5 millones. Luego, inserta tres filas nuevas en la tabla Customers.

GoogleSQL

C++

void AlterSequence(
    google::cloud::spanner_admin::DatabaseAdminClient admin_client,
    google::cloud::spanner::Client 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);
  std::vector<std::string> statements;
  statements.emplace_back(R"""(
      ALTER SEQUENCE Seq
          SET OPTIONS (skip_range_min = 1000, skip_range_max = 5000000)
  )""");
  auto metadata =
      admin_client.UpdateDatabaseDdl(database.FullName(), std::move(statements))
          .get();
  if (!metadata) throw std::move(metadata).status();
  std::cout << "Altered `Seq` sequence"
            << "  to skip an inclusive range between 1000 and 5000000,"
            << " new DDL:\n"
            << metadata->DebugString();
  auto commit = client.Commit(
      [&client](google::cloud::spanner::Transaction txn)
          -> google::cloud::StatusOr<google::cloud::spanner::Mutations> {
        auto sql = google::cloud::spanner::SqlStatement(R"""(
            INSERT INTO Customers (CustomerName)
              VALUES ('Lea'),
                     ('Catalina'),
                     ('Smith')
              THEN RETURN CustomerId
        )""");
        using RowType = std::tuple<std::int64_t>;
        auto rows = client.ExecuteQuery(std::move(txn), std::move(sql));
        // Note: This mutator might be re-run, or its effects discarded, so
        // changing non-transactional state (e.g., by producing output) is,
        // in general, not something to be imitated.
        for (auto& row : google::cloud::spanner::StreamOf<RowType>(rows)) {
          if (!row) return std::move(row).status();
          std::cout << "Inserted customer record with CustomerId: "
                    << std::get<0>(*row) << "\n";
        }
        std::cout << "Number of customer records inserted is: "
                  << rows.RowsModified() << "\n";
        return google::cloud::spanner::Mutations{};
      });
  if (!commit) throw std::move(commit).status();
}

C#

using Google.Cloud.Spanner.Admin.Database.V1;
using Google.Cloud.Spanner.Common.V1;
using Google.Cloud.Spanner.Data;
using System;
using System.Collections.Generic;
using System.Threading.Tasks;

public class AlterSequenceSample
{
    public async Task<List<long>> AlterSequenceSampleAsync(string projectId, string instanceId, string databaseId)
    {
        DatabaseAdminClient databaseAdminClient = DatabaseAdminClient.Create();

        DatabaseName databaseName = DatabaseName.FromProjectInstanceDatabase(projectId, instanceId, databaseId);
        string[] statements =
        {
            "ALTER SEQUENCE Seq SET OPTIONS (skip_range_min = 1000, skip_range_max = 5000000)"
        };
        var operation = await databaseAdminClient.UpdateDatabaseDdlAsync(databaseName, statements);

        var completedResponse = await operation.PollUntilCompletedAsync();
        if (completedResponse.IsFaulted)
        {
            throw completedResponse.Exception;
        }
        Console.WriteLine("Altered Seq sequence to skip an inclusive range between 1000 and 5000000");

        string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
        using var connection = new SpannerConnection(connectionString);
        await connection.OpenAsync();

        using var cmd = connection.CreateDmlCommand(
            @"INSERT INTO Customers (CustomerName) VALUES ('Alice'), ('David'), ('Marc') THEN RETURN CustomerId");

        var reader = await cmd.ExecuteReaderAsync();
        var customerIds = new List<long>();
        while (await reader.ReadAsync())
        {
            long customerId = reader.GetFieldValue<long>("CustomerId");
            Console.WriteLine($"Inserted customer record with CustomerId: {customerId}");
            customerIds.Add(customerId);
        }
        Console.WriteLine($"Number of customer records inserted is: {customerIds.Count}");

        return customerIds;
    }
}

Go

import (
	"context"
	"fmt"
	"io"

	"cloud.google.com/go/spanner"
	database "cloud.google.com/go/spanner/admin/database/apiv1"
	adminpb "cloud.google.com/go/spanner/admin/database/apiv1/databasepb"
	"google.golang.org/api/iterator"
)

func alterSequence(w io.Writer, db string) error {
	// db := "projects/my-project/instances/my-instance/databases/my-database"
	ctx := context.Background()
	adminClient, err := database.NewDatabaseAdminClient(ctx)
	if err != nil {
		return err
	}
	defer adminClient.Close()

	// List of DDL statements to be applied to the database.
	// Alter the sequence to skip range [1000-5000000] for new keys.
	ddl := []string{
		"ALTER SEQUENCE Seq SET OPTIONS (skip_range_min = 1000, skip_range_max = 5000000)",
	}
	op, err := adminClient.UpdateDatabaseDdl(ctx, &adminpb.UpdateDatabaseDdlRequest{
		Database:   db,
		Statements: ddl,
	})
	if err != nil {
		return err
	}
	// Wait for the UpdateDatabaseDdl operation to finish.
	if err := op.Wait(ctx); err != nil {
		return fmt.Errorf("waiting for bit reverse sequence skip range to finish failed: %w", err)
	}
	fmt.Fprintf(w, "Altered Seq sequence to skip an inclusive range between 1000 and 5000000\n")

	client, err := spanner.NewClient(ctx, db)
	if err != nil {
		return err
	}
	defer client.Close()

	// Inserts records into the Customers table.
	// The ReadWriteTransaction function returns the commit timestamp and an error.
	// The commit timestamp is ignored in this case.
	_, err = client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error {
		stmt := spanner.Statement{
			SQL: `INSERT INTO Customers (CustomerName) VALUES ('Lea'), ('Catalina'), ('Smith') THEN RETURN CustomerId`,
		}
		iter := txn.Query(ctx, stmt)
		defer iter.Stop()
		for {
			row, err := iter.Next()
			if err == iterator.Done {
				break
			}
			if err != nil {
				return err
			}
			var customerId int64
			if err := row.Columns(&customerId); err != nil {
				return err
			}
			fmt.Fprintf(w, "Inserted customer record with CustomerId: %d\n", customerId)
		}
		fmt.Fprintf(w, "Number of customer records inserted is: %d\n", iter.RowCount)
		return nil
	})
	return err
}

Java

import com.google.cloud.spanner.DatabaseClient;
import com.google.cloud.spanner.DatabaseId;
import com.google.cloud.spanner.ResultSet;
import com.google.cloud.spanner.Spanner;
import com.google.cloud.spanner.SpannerExceptionFactory;
import com.google.cloud.spanner.SpannerOptions;
import com.google.cloud.spanner.Statement;
import com.google.cloud.spanner.admin.database.v1.DatabaseAdminClient;
import com.google.common.collect.ImmutableList;
import com.google.spanner.admin.database.v1.DatabaseName;
import java.util.Objects;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

public class AlterSequenceSample {

  static void alterSequence() {
    // TODO(developer): Replace these variables before running the sample.
    final String projectId = "my-project";
    final String instanceId = "my-instance";
    final String databaseId = "my-database";
    alterSequence(projectId, instanceId, databaseId);
  }

  static void alterSequence(String projectId, String instanceId, String databaseId) {
    try (Spanner spanner =
        SpannerOptions.newBuilder().setProjectId(projectId).build().getService();
        DatabaseAdminClient databaseAdminClient = spanner.createDatabaseAdminClient()) {

      databaseAdminClient
          .updateDatabaseDdlAsync(DatabaseName.of(projectId, instanceId, databaseId),
              ImmutableList.of(
                  "ALTER SEQUENCE Seq SET OPTIONS "
                      + "(skip_range_min = 1000, skip_range_max = 5000000)"))
          .get(5, TimeUnit.MINUTES);

      System.out.println(
          "Altered Seq sequence to skip an inclusive range between 1000 and 5000000");

      final DatabaseClient dbClient =
          spanner.getDatabaseClient(DatabaseId.of(projectId, instanceId, databaseId));

      Long insertCount =
          dbClient
              .readWriteTransaction()
              .run(
                  transaction -> {
                    try (ResultSet rs =
                        transaction.executeQuery(
                            Statement.of(
                                "INSERT INTO Customers (CustomerName) VALUES "
                                    + "('Lea'), ('Catalina'), ('Smith') "
                                    + "THEN RETURN CustomerId"))) {
                      while (rs.next()) {
                        System.out.printf(
                            "Inserted customer record with CustomerId: %d\n", rs.getLong(0));
                      }
                      return Objects.requireNonNull(rs.getStats()).getRowCountExact();
                    }
                  });
      System.out.printf("Number of customer records inserted is: %d\n", insertCount);
    } catch (ExecutionException e) {
      // If the operation failed during execution, expose the cause.
      throw SpannerExceptionFactory.asSpannerException(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);
    } catch (TimeoutException e) {
      // If the operation timed out propagate the timeout
      throw SpannerExceptionFactory.propagateTimeout(e);
    }
  }
}

Nota: Las muestras de código de la interfaz de la biblioteca cliente anterior para Java se archivan en GitHub:

Node.js

// 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,
});

async function alterSequence(instanceId, databaseId) {
  // Gets a reference to a Cloud Spanner Database Admin Client object
  const databaseAdminClient = spanner.getDatabaseAdminClient();

  const request = [
    'ALTER SEQUENCE Seq SET OPTIONS (skip_range_min = 1000, skip_range_max = 5000000)',
  ];

  try {
    const [operation] = await databaseAdminClient.updateDatabaseDdl({
      database: databaseAdminClient.databasePath(
        projectId,
        instanceId,
        databaseId
      ),
      statements: request,
    });

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

    console.log(
      'Altered Seq sequence to skip an inclusive range between 1000 and 5000000.'
    );
  } catch (err) {
    console.error('ERROR:', err);
  }

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

  database.runTransaction(async (err, transaction) => {
    if (err) {
      console.error(err);
      return;
    }
    try {
      const [rows, stats] = await transaction.run({
        sql: "INSERT INTO Customers (CustomerName) VALUES ('Lea'), ('Catalina'), ('Smith') THEN RETURN CustomerId",
      });

      rows.forEach(row => {
        console.log(
          `Inserted customer record with CustomerId: ${
            row.toJSON({wrapNumbers: true}).CustomerId.value
          }`
        );
      });

      const rowCount = Math.floor(stats[stats.rowCount]);
      console.log(`Number of customer records inserted is: ${rowCount}`);

      await transaction.commit();
    } catch (err) {
      console.error('ERROR:', err);
    } finally {
      // Close the database when finished.
      await database.close();
    }
  });
}
await alterSequence(instanceId, databaseId);

Nota: Las muestras de código de interfaz de la biblioteca cliente anterior para Node.js se archivan en GitHub.

PHP

use Google\Cloud\Spanner\Admin\Database\V1\Client\DatabaseAdminClient;
use Google\Cloud\Spanner\Admin\Database\V1\UpdateDatabaseDdlRequest;
use Google\Cloud\Spanner\Result;
use Google\Cloud\Spanner\SpannerClient;

/**
 * Alters a sequence.
 * Example:
 * ```
 * alter_sequence($projectId, $instanceId, $databaseId);
 * ```
 *
 * @param string $projectId The Google Cloud project ID.
 * @param string $instanceId The Spanner instance ID.
 * @param string $databaseId The Spanner database ID.
 */
function alter_sequence(string $projectId, string $instanceId, string $databaseId): void
{
    $databaseAdminClient = new DatabaseAdminClient();
    $spanner = new SpannerClient();

    $databaseName = DatabaseAdminClient::databaseName($projectId, $instanceId, $databaseId);
    $instance = $spanner->instance($instanceId);
    $database = $instance->database($databaseId);
    $transaction = $database->transaction();

    $statements = [
         'ALTER SEQUENCE Seq SET OPTIONS ' .
        '(skip_range_min = 1000, skip_range_max = 5000000)'
    ];
    $request = new UpdateDatabaseDdlRequest([
        'database' => $databaseName,
        'statements' => $statements
    ]);

    $operation = $databaseAdminClient->updateDatabaseDdl($request);

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

    printf(
        'Altered Seq sequence to skip an inclusive range between 1000 and 5000000' .
        PHP_EOL
    );

    $res = $transaction->execute(
        'INSERT INTO Customers (CustomerName) VALUES ' .
        "('Lea'), ('Catalina'), ('Smith') THEN RETURN CustomerId"
    );
    $rows = $res->rows(Result::RETURN_ASSOCIATIVE);

    foreach ($rows as $row) {
        printf('Inserted customer record with CustomerId: %d %s',
            $row['CustomerId'],
            PHP_EOL
        );
    }
    $transaction->commit();

    printf(sprintf(
        'Number of customer records inserted is: %d %s',
        $res->stats()['rowCountExact'],
        PHP_EOL
    ));
}

Nota: Las muestras de código de interfaz de la biblioteca cliente anterior para PHP están archivadas en GitHub.

Python

def alter_sequence(instance_id, database_id):
    """Alters the Sequence and insert data"""

    from google.cloud.spanner_admin_database_v1.types import \
        spanner_database_admin

    spanner_client = spanner.Client()
    database_admin_api = spanner_client.database_admin_api

    request = spanner_database_admin.UpdateDatabaseDdlRequest(
        database=database_admin_api.database_path(
            spanner_client.project, instance_id, database_id
        ),
        statements=[
            "ALTER SEQUENCE Seq SET OPTIONS (skip_range_min = 1000, skip_range_max = 5000000)",
        ],
    )

    operation = database_admin_api.update_database_ddl(request)

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

    print(
        "Altered Seq sequence to skip an inclusive range between 1000 and 5000000 on database {} on instance {}".format(
            database_id, instance_id
        )
    )

    def insert_customers(transaction):
        results = transaction.execute_sql(
            "INSERT INTO Customers (CustomerName) VALUES "
            "('Lea'), "
            "('Cataline'), "
            "('Smith') "
            "THEN RETURN CustomerId"
        )
        for result in results:
            print("Inserted customer record with Customer Id: {}".format(*result))
        print(
            "Number of customer records inserted is {}".format(
                results.stats.row_count_exact
            )
        )

    instance = spanner_client.instance(instance_id)
    database = instance.database(database_id)

    database.run_in_transaction(insert_customers)

Nota: Las muestras de código de la interfaz de la biblioteca cliente anterior para Python están archivadas en GitHub.

Ruby

require "google/cloud/spanner"

##
# This is a snippet for showcasing how to alter a sequence.
#
# @param project_id  [String] The ID of the Google Cloud project.
# @param instance_id [String] The ID of the spanner instance.
# @param database_id [String] The ID of the database.
#
def spanner_alter_sequence project_id:, instance_id:, database_id:
  db_admin_client = Google::Cloud::Spanner::Admin::Database.database_admin

  database_path = db_admin_client.database_path project: project_id,
                                                instance: instance_id,
                                                database: database_id


  job = db_admin_client.update_database_ddl database: database_path, statements: [
    "ALTER SEQUENCE Seq SET OPTIONS (skip_range_min = 1000, skip_range_max = 5000000)"
  ]

  puts "Waiting for operation to complete..."
  job.wait_until_done!
  puts "Altered Seq sequence to skip an inclusive range between 1000 and 5000000"
end

PostgreSQL

C++

void AlterSequence(
    google::cloud::spanner_admin::DatabaseAdminClient admin_client,
    google::cloud::spanner::Database const& database,
    google::cloud::spanner::Client client) {
  std::vector<std::string> statements;
  statements.emplace_back(R"""(
      ALTER SEQUENCE Seq SKIP RANGE 1000 5000000
  )""");
  auto metadata =
      admin_client.UpdateDatabaseDdl(database.FullName(), std::move(statements))
          .get();
  if (!metadata) throw std::move(metadata).status();
  std::cout << "Altered `Seq` sequence"
            << "  to skip an inclusive range between 1000 and 5000000,"
            << " new DDL:\n"
            << metadata->DebugString();
  auto commit = client.Commit(
      [&client](google::cloud::spanner::Transaction txn)
          -> google::cloud::StatusOr<google::cloud::spanner::Mutations> {
        auto sql = google::cloud::spanner::SqlStatement(R"""(
            INSERT INTO Customers (CustomerName)
                VALUES ('Lea'),
                       ('Catalina'),
                       ('Smith')
                RETURNING CustomerId
        )""");
        using RowType = std::tuple<std::int64_t>;
        auto rows = client.ExecuteQuery(std::move(txn), std::move(sql));
        // Note: This mutator might be re-run, or its effects discarded, so
        // changing non-transactional state (e.g., by producing output) is,
        // in general, not something to be imitated.
        for (auto& row : google::cloud::spanner::StreamOf<RowType>(rows)) {
          if (!row) return std::move(row).status();
          std::cout << "Inserted customer record with CustomerId: "
                    << std::get<0>(*row) << "\n";
        }
        std::cout << "Number of customer records inserted is: "
                  << rows.RowsModified() << "\n";
        return google::cloud::spanner::Mutations{};
      });
  if (!commit) throw std::move(commit).status();
}

C#

using Google.Cloud.Spanner.Admin.Database.V1;
using Google.Cloud.Spanner.Common.V1;
using Google.Cloud.Spanner.Data;
using Google.LongRunning;
using System;
using System.Collections.Generic;
using System.Threading.Tasks;

public class AlterSequencePostgresqlSample
{
    public async Task<List<long>> AlterSequencePostgresqlSampleAsync(string projectId, string instanceId, string databaseId)
    {
        DatabaseAdminClient databaseAdminClient = DatabaseAdminClient.Create();
        DatabaseName databaseName = DatabaseName.FromProjectInstanceDatabase(projectId, instanceId, databaseId);
        string[] statements =
        {
            "ALTER SEQUENCE Seq SKIP RANGE 1000 5000000;"
        };
        var operation = await databaseAdminClient.UpdateDatabaseDdlAsync(databaseName, statements);
        var completedResponse = await operation.PollUntilCompletedAsync();
        if (completedResponse.IsFaulted)
        {
            throw completedResponse.Exception;
        }
        Console.WriteLine("Altered Seq sequence to skip an inclusive range between 1000 and 5000000");

        string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
        using var connection = new SpannerConnection(connectionString);
        await connection.OpenAsync();

        using var cmd = connection.CreateDmlCommand(
            @"INSERT INTO Customers (CustomerName) VALUES ('Alice'), ('David'), ('Marc') RETURNING CustomerId");

        var reader = await cmd.ExecuteReaderAsync();
        var customerIds = new List<long>();
        while (await reader.ReadAsync())
        {
            var customerId = reader.GetFieldValue<long>("customerid");
            Console.WriteLine($"Inserted customer record with CustomerId: {customerId}");
            customerIds.Add(customerId);
        }
        Console.WriteLine($"Number of customer records inserted is: {customerIds.Count}");
        return customerIds;
    }
}

Go

import (
	"context"
	"fmt"
	"io"

	"cloud.google.com/go/spanner"
	database "cloud.google.com/go/spanner/admin/database/apiv1"
	adminpb "cloud.google.com/go/spanner/admin/database/apiv1/databasepb"
	"google.golang.org/api/iterator"
)

func pgAlterSequence(w io.Writer, db string) error {
	// db := "projects/my-project/instances/my-instance/databases/my-database"
	ctx := context.Background()
	adminClient, err := database.NewDatabaseAdminClient(ctx)
	if err != nil {
		return err
	}
	defer adminClient.Close()

	// List of DDL statements to be applied to the database.
	// Alter the sequence to skip range [1000-5000000] for new keys.
	ddl := []string{
		"ALTER SEQUENCE Seq SKIP RANGE 1000 5000000",
	}
	op, err := adminClient.UpdateDatabaseDdl(ctx, &adminpb.UpdateDatabaseDdlRequest{
		Database:   db,
		Statements: ddl,
	})
	if err != nil {
		return err
	}
	// Wait for the UpdateDatabaseDdl operation to finish.
	if err := op.Wait(ctx); err != nil {
		return fmt.Errorf("waiting for bit reverse sequence skip range to finish failed: %w", err)
	}
	fmt.Fprintf(w, "Altered Seq sequence to skip an inclusive range between 1000 and 5000000\n")

	client, err := spanner.NewClient(ctx, db)
	if err != nil {
		return err
	}
	defer client.Close()

	// Inserts records into the Customers table.
	// The ReadWriteTransaction function returns the commit timestamp and an error.
	// The commit timestamp is ignored in this case.
	_, err = client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error {
		stmt := spanner.Statement{
			SQL: `INSERT INTO Customers (CustomerName) VALUES ('Lea'), ('Catalina'), ('Smith') RETURNING CustomerId`,
		}
		iter := txn.Query(ctx, stmt)
		defer iter.Stop()
		for {
			row, err := iter.Next()
			if err == iterator.Done {
				break
			}
			if err != nil {
				return err
			}
			var customerId int64
			if err := row.Columns(&customerId); err != nil {
				return err
			}
			fmt.Fprintf(w, "Inserted customer record with CustomerId: %d\n", customerId)
		}
		fmt.Fprintf(w, "Number of customer records inserted is: %d\n", iter.RowCount)
		return nil
	})
	return err
}

Java

import com.google.cloud.spanner.DatabaseClient;
import com.google.cloud.spanner.DatabaseId;
import com.google.cloud.spanner.ResultSet;
import com.google.cloud.spanner.Spanner;
import com.google.cloud.spanner.SpannerExceptionFactory;
import com.google.cloud.spanner.SpannerOptions;
import com.google.cloud.spanner.Statement;
import com.google.cloud.spanner.admin.database.v1.DatabaseAdminClient;
import com.google.common.collect.ImmutableList;
import com.google.spanner.admin.database.v1.DatabaseName;
import java.util.Objects;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

public class PgAlterSequenceSample {

  static void pgAlterSequence() {
    // TODO(developer): Replace these variables before running the sample.
    final String projectId = "my-project";
    final String instanceId = "my-instance";
    final String databaseId = "my-database";
    pgAlterSequence(projectId, instanceId, databaseId);
  }

  static void pgAlterSequence(String projectId, String instanceId, String databaseId) {
    try (Spanner spanner =
        SpannerOptions.newBuilder().setProjectId(projectId).build().getService();
        DatabaseAdminClient databaseAdminClient = spanner.createDatabaseAdminClient()) {

      databaseAdminClient
          .updateDatabaseDdlAsync(
              DatabaseName.of(projectId, instanceId, databaseId),
              ImmutableList.of("ALTER SEQUENCE Seq SKIP RANGE 1000 5000000"))
          .get(5, TimeUnit.MINUTES);
      System.out.println(
          "Altered Seq sequence to skip an inclusive range between 1000 and 5000000");
      final DatabaseClient dbClient =
          spanner.getDatabaseClient(DatabaseId.of(projectId, instanceId, databaseId));
      Long insertCount =
          dbClient
              .readWriteTransaction()
              .run(
                  transaction -> {
                    try (ResultSet rs =
                        transaction.executeQuery(
                            Statement.of(
                                "INSERT INTO Customers (CustomerName) VALUES "
                                    + "('Lea'), ('Catalina'), ('Smith') RETURNING CustomerId"))) {
                      while (rs.next()) {
                        System.out.printf(
                            "Inserted customer record with CustomerId: %d\n", rs.getLong(0));
                      }
                      return Objects.requireNonNull(rs.getStats()).getRowCountExact();
                    }
                  });
      System.out.printf("Number of customer records inserted is: %d\n", insertCount);
    } catch (ExecutionException e) {
      // If the operation failed during execution, expose the cause.
      throw SpannerExceptionFactory.asSpannerException(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);
    } catch (TimeoutException e) {
      // If the operation timed out propagate the timeout
      throw SpannerExceptionFactory.propagateTimeout(e);
    }
  }
}

Nota: Las muestras de código de la interfaz de la biblioteca cliente anterior para Java se archivan en GitHub:

Node.js

// 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,
});

async function alterSequence(instanceId, databaseId) {
  // Gets a reference to a Cloud Spanner Database Admin Client object
  const databaseAdminClient = spanner.getDatabaseAdminClient();

  const request = ['ALTER SEQUENCE Seq SKIP RANGE 1000 5000000'];

  try {
    const [operation] = await databaseAdminClient.updateDatabaseDdl({
      database: databaseAdminClient.databasePath(
        projectId,
        instanceId,
        databaseId
      ),
      statements: request,
    });

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

    console.log(
      'Altered Seq sequence to skip an inclusive range between 1000 and 5000000.'
    );
  } catch (err) {
    console.error('ERROR:', err);
  }

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

  database.runTransaction(async (err, transaction) => {
    if (err) {
      console.error(err);
      return;
    }
    try {
      const [rows, stats] = await transaction.run({
        sql: "INSERT INTO Customers (CustomerName) VALUES ('Lea'), ('Catalina'), ('Smith') RETURNING CustomerId",
      });

      rows.forEach(row => {
        console.log(
          `Inserted customer record with CustomerId: ${
            row.toJSON({wrapNumbers: true}).customerid.value
          }`
        );
      });

      const rowCount = Math.floor(stats[stats.rowCount]);
      console.log(`Number of customer records inserted is: ${rowCount}`);

      await transaction.commit();
    } catch (err) {
      console.error('ERROR:', err);
    } finally {
      // Close the spanner client when finished.
      // The databaseAdminClient does not require explicit closure. The closure of the Spanner client will automatically close the databaseAdminClient.
      spanner.close();
    }
  });
}
await alterSequence(instanceId, databaseId);

Nota: Las muestras de código de la interfaz de la biblioteca cliente anterior para Node.js se archivan en GitHub:

PHP

use Google\Cloud\Spanner\Admin\Database\V1\Client\DatabaseAdminClient;
use Google\Cloud\Spanner\Admin\Database\V1\UpdateDatabaseDdlRequest;
use Google\Cloud\Spanner\SpannerClient;
use Google\Cloud\Spanner\Result;

/**
 * Alters a sequence.
 * Example:
 * ```
 * pg_alter_sequence($projectId, $instanceId, $databaseId);
 * ```
 *
 * @param string $projectId The Google Cloud project ID.
 * @param string $instanceId The Spanner instance ID.
 * @param string $databaseId The Spanner database ID.
 */
function pg_alter_sequence(
    string $projectId,
    string $instanceId,
    string $databaseId
): void {
    $databaseAdminClient = new DatabaseAdminClient();
    $spanner = new SpannerClient();
    $instance = $spanner->instance($instanceId);
    $database = $instance->database($databaseId);
    $transaction = $database->transaction();
    $databaseName = DatabaseAdminClient::databaseName($projectId, $instanceId, $databaseId);
    $statement = 'ALTER SEQUENCE Seq SKIP RANGE 1000 5000000';
    $request = new UpdateDatabaseDdlRequest([
        'database' => $databaseName,
        'statements' => [$statement]
    ]);

    $operation = $databaseAdminClient->updateDatabaseDdl($request);

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

    printf(
        'Altered Seq sequence to skip an inclusive range between 1000 and 5000000' .
        PHP_EOL
    );

    $res = $transaction->execute(
        'INSERT INTO Customers (CustomerName) VALUES ' .
        "('Lea'), ('Catalina'), ('Smith') RETURNING CustomerId"
    );
    $rows = $res->rows(Result::RETURN_ASSOCIATIVE);

    foreach ($rows as $row) {
        printf('Inserted customer record with CustomerId: %d %s',
            $row['customerid'],
            PHP_EOL
        );
    }
    $transaction->commit();

    printf(sprintf(
        'Number of customer records inserted is: %d %s',
        $res->stats()['rowCountExact'],
        PHP_EOL
    ));
}

Nota: Las muestras de código de la interfaz de la biblioteca cliente anterior para PHP se archivan en GitHub:

Python

def alter_sequence(instance_id, database_id):
    """Alters the Sequence and insert data"""

    from google.cloud.spanner_admin_database_v1.types import \
        spanner_database_admin

    spanner_client = spanner.Client()
    database_admin_api = spanner_client.database_admin_api

    request = spanner_database_admin.UpdateDatabaseDdlRequest(
        database=database_admin_api.database_path(
            spanner_client.project, instance_id, database_id
        ),
        statements=["ALTER SEQUENCE Seq SKIP RANGE 1000 5000000"],
    )
    operation = database_admin_api.update_database_ddl(request)

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

    print(
        "Altered Seq sequence to skip an inclusive range between 1000 and 5000000 on database {} on instance {}".format(
            database_id, instance_id
        )
    )

    def insert_customers(transaction):
        results = transaction.execute_sql(
            "INSERT INTO Customers (CustomerName) VALUES "
            "('Lea'), "
            "('Cataline'), "
            "('Smith') "
            "RETURNING CustomerId"
        )
        for result in results:
            print("Inserted customer record with Customer Id: {}".format(*result))
        print(
            "Number of customer records inserted is {}".format(
                results.stats.row_count_exact
            )
        )

    instance = spanner_client.instance(instance_id)
    database = instance.database(database_id)

    database.run_in_transaction(insert_customers)

Nota: Las muestras de código de la interfaz de la biblioteca cliente anterior para Python se archivan en GitHub:

Ruby

require "google/cloud/spanner"

##
# This is a snippet for showcasing how to alter a sequence using postgresql.
#
# @param project_id  [String] The ID of the Google Cloud project.
# @param instance_id [String] The ID of the spanner instance.
# @param database_id [String] The ID of the database.
#
def spanner_postgresql_alter_sequence project_id:, instance_id:, database_id:
  db_admin_client = Google::Cloud::Spanner::Admin::Database.database_admin

  database_path = db_admin_client.database_path project: project_id,
                                                instance: instance_id,
                                                database: database_id


  job = db_admin_client.update_database_ddl database: database_path, statements: [
    "ALTER SEQUENCE Seq SKIP RANGE 1000 5000000"
  ]

  puts "Waiting for operation to complete..."
  job.wait_until_done!
  puts "Altered Seq sequence to skip an inclusive range between 1000 and 5000000"
end

Cómo soltar una secuencia

En el siguiente ejemplo de código, se altera la tabla Customers para quitar la secuencia Seq del valor predeterminado de la clave primaria y, luego, se descarta la secuencia Seq.

GoogleSQL

C++

void DropSequence(
    google::cloud::spanner_admin::DatabaseAdminClient admin_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);
  std::vector<std::string> statements;
  statements.emplace_back(R"""(
      ALTER TABLE Customers ALTER COLUMN CustomerId DROP DEFAULT
  )""");
  statements.emplace_back(R"""(
      DROP SEQUENCE Seq
  )""");
  auto metadata =
      admin_client.UpdateDatabaseDdl(database.FullName(), std::move(statements))
          .get();
  if (!metadata) throw std::move(metadata).status();
  std::cout << "Altered `Customers` table to"
            << " drop DEFAULT from `CustomerId` column,"
            << " and dropped the `Seq` sequence,"
            << " new DDL:\n"
            << metadata->DebugString();
}

C#

using Google.Cloud.Spanner.Admin.Database.V1;
using Google.Cloud.Spanner.Common.V1;
using System;
using System.Threading.Tasks;

public class DropSequenceSample
{
    public async Task DropSequenceSampleAsync(string projectId, string instanceId, string databaseId)
    {
        DatabaseAdminClient databaseAdminClient = DatabaseAdminClient.Create();

        DatabaseName databaseName = DatabaseName.FromProjectInstanceDatabase(projectId, instanceId, databaseId);
        string[] statements =
        {
            "ALTER TABLE Customers ALTER COLUMN CustomerId DROP DEFAULT",
            "DROP SEQUENCE Seq"
        };
        var operation = await databaseAdminClient.UpdateDatabaseDdlAsync(databaseName, statements);

        var completedResponse = await operation.PollUntilCompletedAsync();
        if (completedResponse.IsFaulted)
        {
            throw completedResponse.Exception;
        }
        Console.WriteLine("Altered Customers table to drop DEFAULT from CustomerId column and dropped the Seq sequence");
    }
}

Go

import (
	"context"
	"fmt"
	"io"

	database "cloud.google.com/go/spanner/admin/database/apiv1"
	adminpb "cloud.google.com/go/spanner/admin/database/apiv1/databasepb"
)

func dropSequence(w io.Writer, db string) error {
	// db := "projects/my-project/instances/my-instance/databases/my-database"
	ctx := context.Background()
	adminClient, err := database.NewDatabaseAdminClient(ctx)
	if err != nil {
		return err
	}
	defer adminClient.Close()

	// List of DDL statements to be applied to the database.
	// Drop the DEFAULT from CustomerId column and drop the sequence.
	ddl := []string{
		"ALTER TABLE Customers ALTER COLUMN CustomerId DROP DEFAULT",
		"DROP SEQUENCE Seq",
	}
	op, err := adminClient.UpdateDatabaseDdl(ctx, &adminpb.UpdateDatabaseDdlRequest{
		Database:   db,
		Statements: ddl,
	})
	if err != nil {
		return err
	}
	// Wait for the UpdateDatabaseDdl operation to finish.
	if err := op.Wait(ctx); err != nil {
		return fmt.Errorf("waiting for bit reverse sequence drop to finish failed: %w", err)
	}
	fmt.Fprintf(w, "Altered Customers table to drop DEFAULT from CustomerId column and dropped the Seq sequence\n")
	return nil
}

Java

import com.google.cloud.spanner.Spanner;
import com.google.cloud.spanner.SpannerExceptionFactory;
import com.google.cloud.spanner.SpannerOptions;
import com.google.cloud.spanner.admin.database.v1.DatabaseAdminClient;
import com.google.common.collect.ImmutableList;
import com.google.spanner.admin.database.v1.DatabaseName;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

public class DropSequenceSample {

  static void dropSequence() {
    // TODO(developer): Replace these variables before running the sample.
    final String projectId = "my-project";
    final String instanceId = "my-instance";
    final String databaseId = "my-database";
    dropSequence(projectId, instanceId, databaseId);
  }

  static void dropSequence(String projectId, String instanceId, String databaseId) {
    try (Spanner spanner =
        SpannerOptions.newBuilder().setProjectId(projectId).build().getService();
        DatabaseAdminClient databaseAdminClient = spanner.createDatabaseAdminClient()) {
      databaseAdminClient
          .updateDatabaseDdlAsync(DatabaseName.of(projectId, instanceId, databaseId),
              ImmutableList.of(
                  "ALTER TABLE Customers ALTER COLUMN CustomerId DROP DEFAULT",
                  "DROP SEQUENCE Seq"))
          .get(5, TimeUnit.MINUTES);
      System.out.println(
          "Altered Customers table to drop DEFAULT from CustomerId column "
              + "and dropped the Seq sequence");
    } catch (ExecutionException e) {
      // If the operation failed during execution, expose the cause.
      throw SpannerExceptionFactory.asSpannerException(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);
    } catch (TimeoutException e) {
      // If the operation timed out propagate the timeout
      throw SpannerExceptionFactory.propagateTimeout(e);
    }
  }
}

Nota: Las muestras de código de la interfaz de la biblioteca cliente anterior para Java se archivan en GitHub:

Node.js

// 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,
});

async function dropSequence(instanceId, databaseId) {
  // Gets a reference to a Cloud Spanner Database Admin Client object
  const databaseAdminClient = spanner.getDatabaseAdminClient();

  const request = [
    'ALTER TABLE Customers ALTER COLUMN CustomerId DROP DEFAULT',
    'DROP SEQUENCE Seq',
  ];

  // Drop sequence from DDL
  try {
    const [operation] = await databaseAdminClient.updateDatabaseDdl({
      database: databaseAdminClient.databasePath(
        projectId,
        instanceId,
        databaseId
      ),
      statements: request,
    });

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

    console.log(
      'Altered Customers table to drop DEFAULT from CustomerId column and dropped the Seq sequence.'
    );
  } catch (err) {
    console.error('ERROR:', err);
  } finally {
    // Close the spanner client when finished.
    // The databaseAdminClient does not require explicit closure. The closure of the Spanner client will automatically close the databaseAdminClient.
    spanner.close();
  }
}
await dropSequence(instanceId, databaseId);

Nota: Las muestras de código de interfaz de la biblioteca cliente anterior para Node.js se archivan en GitHub.

PHP

use Google\Cloud\Spanner\Admin\Database\V1\Client\DatabaseAdminClient;
use Google\Cloud\Spanner\Admin\Database\V1\UpdateDatabaseDdlRequest;

/**
 * Drops a sequence.
 * Example:
 * ```
 * drop_sequence($projectId, $instanceId, $databaseId);
 * ```
 *
 * @param string $projectId The Google Cloud project ID.
 * @param string $instanceId The Spanner instance ID.
 * @param string $databaseId The Spanner database ID.
 */
function drop_sequence(
    string $projectId,
    string $instanceId,
    string $databaseId
): void {
    $databaseAdminClient = new DatabaseAdminClient();
    $databaseName = DatabaseAdminClient::databaseName($projectId, $instanceId, $databaseId);

    $request = new UpdateDatabaseDdlRequest([
        'database' => $databaseName,
        'statements' => [
            'ALTER TABLE Customers ALTER COLUMN CustomerId DROP DEFAULT',
            'DROP SEQUENCE Seq'
        ]
    ]);

    $operation = $databaseAdminClient->updateDatabaseDdl($request);

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

    printf(
        'Altered Customers table to drop DEFAULT from CustomerId ' .
        'column and dropped the Seq sequence' .
        PHP_EOL
    );
}

Nota: Las muestras de código de la interfaz de la biblioteca cliente anterior para PHP se archivan en GitHub:

Python

def drop_sequence(instance_id, database_id):
    """Drops the Sequence"""

    from google.cloud.spanner_admin_database_v1.types import \
        spanner_database_admin

    spanner_client = spanner.Client()
    database_admin_api = spanner_client.database_admin_api

    request = spanner_database_admin.UpdateDatabaseDdlRequest(
        database=database_admin_api.database_path(
            spanner_client.project, instance_id, database_id
        ),
        statements=[
            "ALTER TABLE Customers ALTER COLUMN CustomerId DROP DEFAULT",
            "DROP SEQUENCE Seq",
        ],
    )

    operation = database_admin_api.update_database_ddl(request)

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

    print(
        "Altered Customers table to drop DEFAULT from CustomerId column and dropped the Seq sequence on database {} on instance {}".format(
            database_id, instance_id
        )
    )

Nota: Las muestras de código de la interfaz de la biblioteca cliente anterior para Python están archivadas en GitHub.

Ruby

require "google/cloud/spanner"

##
# This is a snippet for showcasing how to drop a sequence.
#
# @param project_id  [String] The ID of the Google Cloud project.
# @param instance_id [String] The ID of the spanner instance.
# @param database_id [String] The ID of the database.
#
def spanner_drop_sequence project_id:, instance_id:, database_id:
  db_admin_client = Google::Cloud::Spanner::Admin::Database.database_admin

  database_path = db_admin_client.database_path project: project_id,
                                                instance: instance_id,
                                                database: database_id


  job = db_admin_client.update_database_ddl database: database_path, statements: [
    "ALTER TABLE Customers ALTER COLUMN CustomerId DROP DEFAULT",
    "DROP SEQUENCE Seq"
  ]

  puts "Waiting for operation to complete..."
  job.wait_until_done!
  puts "Altered Customers table to drop DEFAULT from CustomerId column and dropped the Seq sequence"
end

PostgreSQL

C++

void DropSequence(
    google::cloud::spanner_admin::DatabaseAdminClient admin_client,
    google::cloud::spanner::Database const& database) {
  std::vector<std::string> statements;
  statements.emplace_back(R"""(
      ALTER TABLE Customers ALTER COLUMN CustomerId DROP DEFAULT
  )""");
  statements.emplace_back(R"""(
      DROP SEQUENCE Seq
  )""");
  auto metadata =
      admin_client.UpdateDatabaseDdl(database.FullName(), std::move(statements))
          .get();
  if (!metadata) throw std::move(metadata).status();
  std::cout << "Altered `Customers` table to"
            << " drop DEFAULT from `CustomerId` column,"
            << " and dropped the `Seq` sequence,"
            << " new DDL:\n"
            << metadata->DebugString();
}

C#

using Google.Cloud.Spanner.Admin.Database.V1;
using Google.Cloud.Spanner.Common.V1;
using System;
using System.Threading.Tasks;

public class DropSequenceSample
{
    public async Task DropSequenceSampleAsync(string projectId, string instanceId, string databaseId)
    {
        DatabaseAdminClient databaseAdminClient = DatabaseAdminClient.Create();

        DatabaseName databaseName = DatabaseName.FromProjectInstanceDatabase(projectId, instanceId, databaseId);
        string[] statements =
        {
            "ALTER TABLE Customers ALTER COLUMN CustomerId DROP DEFAULT",
            "DROP SEQUENCE Seq"
        };
        var operation = await databaseAdminClient.UpdateDatabaseDdlAsync(databaseName, statements);

        var completedResponse = await operation.PollUntilCompletedAsync();
        if (completedResponse.IsFaulted)
        {
            throw completedResponse.Exception;
        }
        Console.WriteLine("Altered Customers table to drop DEFAULT from CustomerId column and dropped the Seq sequence");
    }
}

Go

import (
	"context"
	"fmt"
	"io"

	database "cloud.google.com/go/spanner/admin/database/apiv1"
	adminpb "cloud.google.com/go/spanner/admin/database/apiv1/databasepb"
)

func dropSequence(w io.Writer, db string) error {
	// db := "projects/my-project/instances/my-instance/databases/my-database"
	ctx := context.Background()
	adminClient, err := database.NewDatabaseAdminClient(ctx)
	if err != nil {
		return err
	}
	defer adminClient.Close()

	// List of DDL statements to be applied to the database.
	// Drop the DEFAULT from CustomerId column and drop the sequence.
	ddl := []string{
		"ALTER TABLE Customers ALTER COLUMN CustomerId DROP DEFAULT",
		"DROP SEQUENCE Seq",
	}
	op, err := adminClient.UpdateDatabaseDdl(ctx, &adminpb.UpdateDatabaseDdlRequest{
		Database:   db,
		Statements: ddl,
	})
	if err != nil {
		return err
	}
	// Wait for the UpdateDatabaseDdl operation to finish.
	if err := op.Wait(ctx); err != nil {
		return fmt.Errorf("waiting for bit reverse sequence drop to finish failed: %w", err)
	}
	fmt.Fprintf(w, "Altered Customers table to drop DEFAULT from CustomerId column and dropped the Seq sequence\n")
	return nil
}

Java

import com.google.cloud.spanner.Spanner;
import com.google.cloud.spanner.SpannerExceptionFactory;
import com.google.cloud.spanner.SpannerOptions;
import com.google.cloud.spanner.admin.database.v1.DatabaseAdminClient;
import com.google.common.collect.ImmutableList;
import com.google.spanner.admin.database.v1.DatabaseName;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

public class PgDropSequenceSample {

  static void pgDropSequence() {
    // TODO(developer): Replace these variables before running the sample.
    final String projectId = "my-project";
    final String instanceId = "my-instance";
    final String databaseId = "my-database";
    pgDropSequence(projectId, instanceId, databaseId);
  }

  static void pgDropSequence(String projectId, String instanceId, String databaseId) {

    try (Spanner spanner =
        SpannerOptions.newBuilder().setProjectId(projectId).build().getService();
        DatabaseAdminClient databaseAdminClient = spanner.createDatabaseAdminClient()) {
      databaseAdminClient
          .updateDatabaseDdlAsync(
              DatabaseName.of(projectId, instanceId, databaseId),
              ImmutableList.of(
                  "ALTER TABLE Customers ALTER COLUMN CustomerId DROP DEFAULT",
                  "DROP SEQUENCE Seq"))
          .get(5, TimeUnit.MINUTES);
      System.out.println(
          "Altered Customers table to drop DEFAULT from "
              + "CustomerId column and dropped the Seq sequence");
    } catch (ExecutionException e) {
      // If the operation failed during execution, expose the cause.
      throw SpannerExceptionFactory.asSpannerException(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);
    } catch (TimeoutException e) {
      // If the operation timed out propagate the timeout
      throw SpannerExceptionFactory.propagateTimeout(e);
    }
  }
}

Nota: Las muestras de código de interfaz de la biblioteca cliente anterior para Java se archivan en GitHub.

Node.js

// 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,
});

async function dropSequence(instanceId, databaseId) {
  // Gets a reference to a Cloud Spanner Database Admin Client object
  const databaseAdminClient = spanner.getDatabaseAdminClient();

  const request = [
    'ALTER TABLE Customers ALTER COLUMN CustomerId DROP DEFAULT',
    'DROP SEQUENCE Seq',
  ];

  // Drop sequence from DDL
  try {
    const [operation] = await databaseAdminClient.updateDatabaseDdl({
      database: databaseAdminClient.databasePath(
        projectId,
        instanceId,
        databaseId
      ),
      statements: request,
    });

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

    console.log(
      'Altered Customers table to drop DEFAULT from CustomerId column and dropped the Seq sequence.'
    );
  } catch (err) {
    console.error('ERROR:', err);
  } finally {
    // Close the spanner client when finished.
    // The databaseAdminClient does not require explicit closure. The closure of the Spanner client will automatically close the databaseAdminClient.
    spanner.close();
  }
}
await dropSequence(instanceId, databaseId);

Nota: Las muestras de código de interfaz de la biblioteca cliente anterior para Node.js se archivan en GitHub.

PHP

use Google\Cloud\Spanner\Admin\Database\V1\Client\DatabaseAdminClient;
use Google\Cloud\Spanner\Admin\Database\V1\UpdateDatabaseDdlRequest;

/**
 * Drops a sequence.
 * Example:
 * ```
 * pg_drop_sequence($instanceId, $databaseId);
 * ```
 *
 * @param string $projectId Your Google Cloud project ID.
 * @param string $instanceId The Spanner instance ID.
 * @param string $databaseId The Spanner database ID.
 */
function pg_drop_sequence(
    string $projectId,
    string $instanceId,
    string $databaseId
): void {
    $databaseAdminClient = new DatabaseAdminClient();
    $databaseName = DatabaseAdminClient::databaseName($projectId, $instanceId, $databaseId);
    $statements = [
        'ALTER TABLE Customers ALTER COLUMN CustomerId DROP DEFAULT',
        'DROP SEQUENCE Seq'
    ];

    $request = new UpdateDatabaseDdlRequest([
        'database' => $databaseName,
        'statements' => $statements
    ]);

    $operation = $databaseAdminClient->updateDatabaseDdl($request);

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

    printf(
        'Altered Customers table to drop DEFAULT from CustomerId ' .
        'column and dropped the Seq sequence' .
        PHP_EOL
    );
}

Nota: Las muestras de código de la interfaz de la biblioteca cliente anterior para PHP se archivan en GitHub:

Python

def drop_sequence(instance_id, database_id):
    """Drops the Sequence"""

    from google.cloud.spanner_admin_database_v1.types import \
        spanner_database_admin

    spanner_client = spanner.Client()
    database_admin_api = spanner_client.database_admin_api

    request = spanner_database_admin.UpdateDatabaseDdlRequest(
        database=database_admin_api.database_path(
            spanner_client.project, instance_id, database_id
        ),
        statements=[
            "ALTER TABLE Customers ALTER COLUMN CustomerId DROP DEFAULT",
            "DROP SEQUENCE Seq",
        ],
    )
    operation = database_admin_api.update_database_ddl(request)

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

    print(
        "Altered Customers table to drop DEFAULT from CustomerId column and dropped the Seq sequence on database {} on instance {}".format(
            database_id, instance_id
        )
    )

Nota: Las muestras de código de la interfaz de la biblioteca cliente anterior para Python están archivadas en GitHub.

Ruby

require "google/cloud/spanner"

##
# This is a snippet for showcasing how to drop a sequence using postgresql.
#
# @param project_id  [String] The ID of the Google Cloud project.
# @param instance_id [String] The ID of the spanner instance.
# @param database_id [String] The ID of the database.
#
def spanner_postgresql_drop_sequence project_id:, instance_id:, database_id:
  db_admin_client = Google::Cloud::Spanner::Admin::Database.database_admin

  database_path = db_admin_client.database_path project: project_id,
                                                instance: instance_id,
                                                database: database_id


  job = db_admin_client.update_database_ddl database: database_path, statements: [
    "ALTER TABLE Customers ALTER COLUMN CustomerId DROP DEFAULT",
    "DROP SEQUENCE Seq"
  ]

  puts "Waiting for operation to complete..."
  job.wait_until_done!
  puts "Altered Customers table to drop DEFAULT from CustomerId column and dropped the Seq sequence"
end