Cloud Spanner Client Libraries

This page shows how to get started with the Cloud Client Libraries for the Cloud Spanner API. Read more about the client libraries for Cloud APIs, including the older Google APIs Client Libraries, in Client Libraries Explained.

The Cloud Spanner client libraries mentioned on this page are supported on Compute Engine, App Engine flexible environment, Google Kubernetes Engine, and Cloud Functions. The Cloud Spanner client library for Java is supported on App Engine standard environment with Java 8.

If you are using the App Engine standard environment with Go, PHP, or Python, use the REST interface to access Cloud Spanner.

Note: Additional client libraries are available for Java applications.

Installing the client library

C#

For more information, see Setting Up a C# Development Environment. To install the Google.Cloud.Spanner.Data client library in Visual Studio, do the following:

1. Right-click your solution in Visual Studio and select Manage Nuget packages for solution.

2. Select the Include prerelease checkbox.

3. Search for and install the package named Google.Cloud.Spanner.Data.

Go

go get -u cloud.google.com/go/spanner/...

Java

For more information, see Setting Up a Java Development Environment.

Nota: Si tu aplicación usa el marco de trabajo de Spring, también estará disponible un módulo de Spring Data.

Si usas Maven, agrega lo siguiente al archivo pom.xml:

<dependency>
  <groupId>com.google.cloud</groupId>
  <artifactId>google-cloud-spanner</artifactId>
  <version>1.45.0</version>
</dependency>

Si usas Gradle, agrega lo siguiente a tus dependencias:

compile 'com.google.cloud:google-cloud-spanner:1.45.0'

Si usas SBT, agrega lo siguiente a tus dependencias:

libraryDependencies += "com.google.cloud" % "google-cloud-spanner" % "1.45.0"

Si usas IntelliJ o Eclipse, puedes agregar bibliotecas cliente a tu proyecto mediante los siguientes complementos IDE:

• Cloud Code para IntelliJ
• Cloud Tools for Eclipse

Los complementos brindan funcionalidades adicionales, como administración de claves para las cuentas de servicio. Consulta la documentación de cada complemento para obtener más detalles.

Nota: En este momento, las bibliotecas cliente de Cloud para Java no son compatibles con Android.

Node.js

For more information, see Setting Up a Node.js Development Environment.

npm install --save @google-cloud/spanner

PHP

composer require google/cloud-spanner

Note: The Cloud Spanner Client Library requires that you install and enable the gRPC extension for PHP.

Python

For more information, see Setting Up a Python Development Environment.

pip install --upgrade google-cloud-spanner

Ruby

For more information, see Setting Up a Ruby Development Environment.

gem install google-cloud-spanner

Setting up authentication

To run the client library, you must first set up authentication by creating a service account and setting an environment variable. Complete the following steps to set up authentication. For other ways to authenticate, see the GCP authentication documentation.

GCP Console

1. En GCP Console, ve a la página Crear clave de la cuenta de servicio.

   Ir a la página Crear clave de la cuenta de servicio
2. En la lista Cuenta de servicio, selecciona Cuenta de servicio nueva.
3. Ingresa un nombre en el campo Nombre de cuenta de servicio.

4. En la lista Función, selecciona Proyecto > Propietario.

   Nota: El campo Función autoriza tu cuenta de servicio para acceder a los recursos. Puedes ver y cambiar este campo luego con GCP Console. Si desarrollas una app de producción, especifica permisos más detallados que Proyecto > Propietario. Para obtener más información, consulta Cómo otorgar funciones a las cuentas de servicio.
5. Haz clic en Crear. Se descargará un archivo JSON a tu computadora que contiene tus descargas de claves.

Línea de comandos

Puedes ejecutar los siguientes comandos con el SDK de Cloud en tu máquina local o en Cloud Shell.

1. Crea la cuenta de servicio. Reemplaza [NOMBRE] por un nombre para la cuenta de servicio.

   gcloud iam service-accounts create [NAME]

2. Otorga permisos a la cuenta de servicio. Reemplaza [PROJECT_ID] por el ID del proyecto.

   gcloud projects add-iam-policy-binding [PROJECT_ID] --member "serviceAccount:[NAME]@[PROJECT_ID].iam.gserviceaccount.com" --role "roles/owner"

   Nota: El campo Función autoriza a tu cuenta de servicio para acceder a los recursos. Puedes ver y cambiar este campo luego con GCP Console. Si desarrollas una app de producción, especifica permisos más detallados que Proyecto > Propietario. Para obtener más información, consulta Cómo otorgar funciones a las cuentas de servicio.

3. Genera el archivo de claves. Reemplaza [FILE_NAME] por un nombre para el archivo de claves.

   gcloud iam service-accounts keys create [FILE_NAME].json --iam-account [NAME]@[PROJECT_ID].iam.gserviceaccount.com

Proporciona credenciales de autenticación a tu código de la aplicación configurando la variable de entorno GOOGLE_APPLICATION_CREDENTIALS. Reemplaza [PATH] con la ruta de acceso al archivo JSON que contiene la clave de tu cuenta de servicio y [FILE_NAME] con el nombre del archivo. Esta variable solo se aplica a la sesión actual de shell. Por lo tanto, si abres una sesión nueva, deberás volver a configurar la variable.

Linux o macOS

export GOOGLE_APPLICATION_CREDENTIALS="[PATH]"

Por ejemplo:

export GOOGLE_APPLICATION_CREDENTIALS="/home/user/Downloads/[FILE_NAME].json"

Windows

Con PowerShell:

$env:GOOGLE_APPLICATION_CREDENTIALS="[PATH]"

Por ejemplo:

$env:GOOGLE_APPLICATION_CREDENTIALS="C:\Users\username\Downloads\[FILE_NAME].json"

Con el símbolo del sistema:

set GOOGLE_APPLICATION_CREDENTIALS=[PATH]

Using the client library

The following example shows how to use the client library.

C#

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

namespace GoogleCloudSamples.Spanner
{
    public class QuickStart
    {
        static async Task MainAsync()
        {
            string projectId = "YOUR-PROJECT-ID";
            string instanceId = "my-instance";
            string databaseId = "my-database";
            string connectionString =
                $"Data Source=projects/{projectId}/instances/{instanceId}/"
                + $"databases/{databaseId}";
            // Create connection to Cloud Spanner.
            using (var connection = new SpannerConnection(connectionString))
            {
                // Execute a simple SQL statement.
                var cmd = connection.CreateSelectCommand(
                    @"SELECT ""Hello World"" as test");
                using (var reader = await cmd.ExecuteReaderAsync())
                {
                    while (await reader.ReadAsync())
                    {
                        Console.WriteLine(
                            reader.GetFieldValue<string>("test"));
                    }
                }
            }
        }
        public static void Main(string[] args)
        {
            MainAsync().Wait();
        }
    }
}

Go

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// Sample spanner_quickstart is a basic program that uses Cloud Spanner.
package main

import (
	"context"
	"fmt"
	"log"

	"cloud.google.com/go/spanner"
	"google.golang.org/api/iterator"
)

func main() {
	ctx := context.Background()

	// This database must exist.
	databaseName := "projects/your-project-id/instances/your-instance-id/databases/your-database-id"

	client, err := spanner.NewClient(ctx, databaseName)
	if err != nil {
		log.Fatalf("Failed to create client %v", err)
	}
	defer client.Close()

	stmt := spanner.Statement{SQL: "SELECT 1"}
	iter := client.Single().Query(ctx, stmt)
	defer iter.Stop()

	for {
		row, err := iter.Next()
		if err == iterator.Done {
			fmt.Println("Done")
			return
		}
		if err != nil {
			log.Fatalf("Query failed with %v", err)
		}

		var i int64
		if row.Columns(&i) != nil {
			log.Fatalf("Failed to parse row %v", err)
		}
		fmt.Printf("Got value %v\n", i)
	}
}

Java

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// Imports the Google Cloud client library
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.SpannerOptions;
import com.google.cloud.spanner.Statement;

/**
 * A quick start code for Cloud Spanner. It demonstrates how to setup the Cloud Spanner client and
 * execute a simple query using it against an existing database.
 */
public class QuickstartSample {
  public static void main(String... args) throws Exception {

    if (args.length != 2) {
      System.err.println("Usage: QuickStartSample <instance_id> <database_id>");
      return;
    }
    // Instantiates a client
    SpannerOptions options = SpannerOptions.newBuilder().build();
    Spanner spanner = options.getService();

    // Name of your instance & database.
    String instanceId = args[0];
    String databaseId = args[1];
    try {
      // Creates a database client
      DatabaseClient dbClient = spanner.getDatabaseClient(DatabaseId.of(
          options.getProjectId(), instanceId, databaseId));
      // Queries the database
      ResultSet resultSet = dbClient.singleUse().executeQuery(Statement.of("SELECT 1"));

      System.out.println("\n\nResults:");
      // Prints the results
      while (resultSet.next()) {
        System.out.printf("%d\n\n", resultSet.getLong(0));
      }
    } finally {
      // Closes the client which will free up the resources used
      spanner.close();
    }
  }
}

Node.js

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

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

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

// The query to execute
const query = {
  sql: 'SELECT 1',
};

// Execute a simple SQL statement
const [rows] = await database.run(query);
console.log(`Query: ${rows.length} found.`);
rows.forEach(row => console.log(row));

PHP

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# Includes the autoloader for libraries installed with composer
require __DIR__ . '/vendor/autoload.php';

# Imports the Google Cloud client library
use Google\Cloud\Spanner\SpannerClient;

# Your Google Cloud Platform project ID
$projectId = 'YOUR_PROJECT_ID';

# Instantiates a client
$spanner = new SpannerClient([
    'projectId' => $projectId
]);

# Your Cloud Spanner instance ID.
$instanceId = 'your-instance-id';

# Get a Cloud Spanner instance by ID.
$instance = $spanner->instance($instanceId);

# Your Cloud Spanner database ID.
$databaseId = 'your-database-id';

# Get a Cloud Spanner database by ID.
$database = $instance->database($databaseId);

# Execute a simple SQL statement.
$results = $database->execute('SELECT "Hello World" as test');

foreach ($results as $row) {
    print($row['test'] . PHP_EOL);
}

Python

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# Imports the Google Cloud Client Library.
from google.cloud import spanner

# Instantiate a client.
spanner_client = spanner.Client()

# Your Cloud Spanner instance ID.
instance_id = 'my-instance-id'

# Get a Cloud Spanner instance by ID.
instance = spanner_client.instance(instance_id)

# Your Cloud Spanner database ID.
database_id = 'my-database-id'

# Get a Cloud Spanner database by ID.
database = instance.database(database_id)

# Execute a simple SQL statement.
with database.snapshot() as snapshot:
    results = snapshot.execute_sql('SELECT 1')

    for row in results:
        print(row)

Ruby

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# Imports the Google Cloud client library
require "google/cloud/spanner"

# Your Google Cloud Platform project ID
project_id = "YOUR_PROJECT_ID"

# Instantiates a client
spanner = Google::Cloud::Spanner.new project: project_id

# Your Cloud Spanner instance ID
instance_id = "my-instance"

# Your Cloud Spanner database ID
database_id = "my-database"

# Gets a reference to a Cloud Spanner instance database
database_client = spanner.client instance_id, database_id

# Execute a simple SQL statement
database_client.transaction do |transaction|
  results = transaction.execute "SELECT 1"

  results.rows.each do |row|
    puts row
  end
end

Additional resources

C#

• API Reference Documentation
• Source Code
• GitHub Issue Tracker
• Stack Overflow

Go

• API Reference Documentation
• Source Code
• GitHub Issue Tracker
• Stack Overflow

Java

• API Reference Documentation
• Source Code
• GitHub Issue Tracker
• Stack Overflow

Node.js

• API Reference Documentation
• Source Code
• GitHub Issue Tracker
• Stack Overflow

PHP

• API Reference Documentation
• Source Code
• GitHub Issue Tracker
• Stack Overflow

Python

• API Reference Documentation
• Source Code
• GitHub Issue Tracker
• Stack Overflow

Ruby

• API Reference Documentation
• Source Code
• GitHub Issue Tracker
• Stack Overflow

Additional client libraries

In addition to the libraries shown above, a Spring Data module is available for Java applications. Spring Data Cloud Spanner helps you use Cloud Spanner in any application that's built with the Spring Framework.

To get started, learn how to add Spring Data Cloud Spanner to your application.