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.

Installing the client library

C++

See the GitHub quickstart documents for details about this client library's requirements and install dependencies.

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

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

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

Java

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

如果您使用的是 Maven,请将以下代码添加到您的 pom.xml 文件中。如需详细了解 BOM,请参阅 Google Cloud Platform 库 BOM

<dependencyManagement>
  <dependencies>
    <dependency>
      <groupId>com.google.cloud</groupId>
      <artifactId>libraries-bom</artifactId>
      <version>16.2.1</version>
      <type>pom</type>
      <scope>import</scope>
    </dependency>
  </dependencies>
</dependencyManagement>

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

如果您使用的是 Gradle,请将以下代码添加到您的依赖项中:

implementation platform('com.google.cloud:libraries-bom:16.2.1')

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

如果您使用的是 sbt,请将以下代码添加到您的依赖项中:

libraryDependencies += "com.google.cloud" % "google-cloud-spanner" % "3.3.0"

如果您使用的是 IntelliJ 或 Eclipse,请通过以下 IDE 插件将客户端库添加到您的项目中:

上述插件还提供其他功能,例如服务帐号密钥管理。如需了解详情,请参阅各个插件相应的文档。

Node.js

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

npm install --save @google-cloud/spanner

PHP

For more information, see Using PHP on Google Cloud.

composer require google/cloud-spanner

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.

Cloud Console

  1. 在 Cloud Console 中,转到创建服务帐号密钥页面。

    转到“创建服务帐号密钥”页面
  2. 服务帐号列表中,选择新的服务帐号
  3. 服务帐号名称字段中,输入一个名称。
  4. 角色列表中,选择 Project > Owner

  5. 点击创建。包含密钥的 JSON 文件就会下载到计算机。

命令行

您可以使用本地机器上的 Cloud SDK 或在 Cloud Shell 中运行以下命令。

  1. 创建服务帐号。将 NAME 替换为服务帐号的名称。

    gcloud iam service-accounts create NAME
  2. 向服务帐号授予权限。将 PROJECT_ID 替换为您的项目 ID。

    gcloud projects add-iam-policy-binding PROJECT_ID --member="serviceAccount:NAME@PROJECT_ID.iam.gserviceaccount.com" --role="roles/owner"
  3. 生成密钥文件。将 FILE_NAME 替换为密钥文件的名称。

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

通过设置环境变量 GOOGLE_APPLICATION_CREDENTIALS 向应用代码提供身份验证凭据。 将 [PATH] 替换为包含您的服务帐号密钥的 JSON 文件的路径。此变量仅适用于当前的 Shell 会话,因此,如果您打开新的会话,请重新设置该变量。

Linux 或 macOS

export GOOGLE_APPLICATION_CREDENTIALS="[PATH]"

例如:

export GOOGLE_APPLICATION_CREDENTIALS="/home/user/Downloads/my-key.json"

Windows

使用 PowerShell:

$env:GOOGLE_APPLICATION_CREDENTIALS="[PATH]"

例如:

$env:GOOGLE_APPLICATION_CREDENTIALS="C:\Users\username\Downloads\my-key.json"

使用命令提示符:

set GOOGLE_APPLICATION_CREDENTIALS=[PATH]

Using 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 const& row : spanner::StreamOf<RowType>(rows)) {
    if (!row) throw std::runtime_error(row.status().message());
    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

# 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

# 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

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.