Spanner client libraries

This page shows how to get started with the Cloud Client Libraries for the Cloud Spanner API. Client libraries make it easier to access Google Cloud APIs from a supported language. Although you can use Google Cloud APIs directly by making raw requests to the server, client libraries provide simplifications that significantly reduce the amount of code you need to write.

Read more about the Cloud Client Libraries and the older Google API Client Libraries in Client libraries explained.

Spanner provides client libraries for popular programming languages, including C++, C#, Go, Java, Node.js, PHP, Python, and Ruby. The client libraries connect to the Spanner service using gRPC over a TLS-encrypted HTTP/2 connection, so you don't need to manually configure SSL or TLS.

The Spanner client libraries are supported on Compute Engine, App Engine flexible environment, Google Kubernetes Engine, and Cloud Run functions. The Spanner client library for Java is also 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 Spanner.

Install the client library

C++

For more information about installing the C++ library, see the Setting up a C++ development environment guide.

C#

To install the Google.Cloud.Spanner.Data client library in Visual Studio, do the following:

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

Select the Include prerelease checkbox.

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

For more information, see Setting Up a C# Development Environment.

Go

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

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

Java

If you are using Maven, add the following to your pom.xml file. For more information about BOMs, see The Google Cloud Platform Libraries BOM.

<dependencyManagement>
  <dependencies>
    <dependency>
      <groupId>com.google.cloud</groupId>
      <artifactId>libraries-bom</artifactId>
      <version>26.78.0</version>
      <type>pom</type>
      <scope>import</scope>
    </dependency>
  </dependencies>
</dependencyManagement>

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

If you are using Gradle, add the following to your dependencies:

implementation platform('com.google.cloud:libraries-bom:26.78.0')

implementation 'com.google.cloud:google-cloud-spanner'

If you are using sbt, add the following to your dependencies:

libraryDependencies += "com.google.cloud" % "google-cloud-spanner" % "6.113.0"

If you're using Visual Studio Code or IntelliJ, you can add client libraries to your project using the following IDE plugins:

The plugins provide additional functionality, such as key management for service accounts. Refer to each plugin's documentation for details.

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

Node.js

npm install @google-cloud/spanner

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

PHP

composer require google/cloud-spanner

For more information, see Using PHP on Google Cloud.

Python

pip install --upgrade google-cloud-spanner

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

Ruby

gem install google-cloud-spanner

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

Set up authentication

To authenticate calls to Google Cloud APIs, client libraries support Application Default Credentials (ADC); the libraries look for credentials in a set of defined locations and use those credentials to authenticate requests to the API. With ADC, you can make credentials available to your application in a variety of environments, such as local development or production, without needing to modify your application code.

For production environments, the way you set up ADC depends on the service and context. For more information, see Set up Application Default Credentials.

For a local development environment, you can set up ADC with the credentials that are associated with your Google Account:

Install the Google Cloud CLI. After installation, initialize the Google Cloud CLI by running the following command:
```
gcloud init
```
If you're using an external identity provider (IdP), you must first sign in to the gcloud CLI with your federated identity.
If you're using a local shell, then create local authentication credentials for your user account:
```
gcloud auth application-default login
```
You don't need to do this if you're using Cloud Shell.

If an authentication error is returned, and you are using an external identity provider (IdP), confirm that you have signed in to the gcloud CLI with your federated identity.

A sign-in screen appears. After you sign in, your credentials are stored in the local credential file used by ADC.

Use the client library

The following example shows how to use the client library.

C++

#include "google/cloud/spanner/client.h"
void Quickstart(std::string const& project_id, std::string const& instance_id,
                std::string const& database_id) {
  namespace spanner = ::google::cloud::spanner;

  auto database = spanner::Database(project_id, instance_id, database_id);
  auto connection = spanner::MakeConnection(database);
  auto client = spanner::Client(connection);

  auto rows =
      client.ExecuteQuery(spanner::SqlStatement("SELECT 'Hello World'"));
  using RowType = std::tuple<std::string>;
  for (auto& row : spanner::StreamOf<RowType>(rows)) {
    if (!row) throw std::move(row).status();
    std::cout << std::get<0>(*row) << "\n";
  }
}

C#


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


// 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

// 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

// 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

# 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

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

# Your Cloud Spanner instance ID.
# instance_id = "my-instance-id"
#
# Your Cloud Spanner database ID.
# database_id = "my-database-id"
# Instantiate a client.
spanner_client = spanner.Client()

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

# 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
results = database_client.execute_query "SELECT 1"
results.rows.each do |row|
  puts row
end

Use the client library for administrator operations

The following list contains links to all the administrator operations you can use in the Spanner client library:

Use Spanner Graph with client libraries

You can use client libraries to setup, modify, and query property graphs in Spanner Graph. The following list contains links to learn about and get started with Spanner Graph using client libraries:

Additional resources

C++

Spanner client libraries Stay organized with collections Save and categorize content based on your preferences.

Install the client library

C++

C#

Go

Java

Node.js

PHP

Python

Ruby

Set up authentication

Use the client library

C++

C#

Go

Java

Node.js

PHP

Python

Ruby

Use the client library for administrator operations

Use Spanner Graph with client libraries

Additional resources

C++

C#

Go

Java

Node.js

PHP

Python

Ruby

Additional client libraries

Spanner client libraries