Datastore mode Client Libraries

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

Installing the client library

C#

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

Install-Package Google.Cloud.Datastore.V1

Go

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

Java

For more information, see Setting Up a Java Development Environment. If you are using Maven, add the following to your pom.xml file:

<dependency>
  <groupId>com.google.cloud</groupId>
  <artifactId>google-cloud-datastore</artifactId>
  <version>1.90.0</version>
</dependency>

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

compile 'com.google.cloud:google-cloud-datastore:1.90.0'

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

libraryDependencies += "com.google.cloud" % "google-cloud-datastore" % "1.90.0"

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

• Cloud Code for IntelliJ
• Cloud Tools for Eclipse

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

Note: Cloud Java client libraries do not currently support Android.

Node.js

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

npm install --save @google-cloud/datastore

PHP

composer require google/cloud-datastore

Python

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

pip install --upgrade google-cloud-datastore

Ruby

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

gem install google-cloud-datastore

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 more information, see the GCP authentication documentation .

GCP Console

1. In the GCP Console, go to the Create service account key page.

   Go to the Create Service Account Key page
2. From the Service account list, select New service account.
3. In the Service account name field, enter a name.

4. From the Role list, select Project > Owner.

   Note: The Role field authorizes your service account to access resources. You can view and change this field later by using the GCP Console. If you are developing a production app, specify more granular permissions than Project > Owner. For more information, see granting roles to service accounts.
5. Click Create. A JSON file that contains your key downloads to your computer.

Command line

You can run the following commands using the Cloud SDK on your local machine, or in Cloud Shell.

1. Create the service account. Replace [NAME] with a name for the service account.

   gcloud iam service-accounts create [NAME]

2. Grant permissions to the service account. Replace [PROJECT_ID] with your project ID.

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

   Note: The Role field authorizes your service account to access resources. You can view and change this field later by using GCP Console. If you are developing a production app, specify more granular permissions than Project > Owner. For more information, see granting roles to service accounts.

3. Generate the key file. Replace [FILE_NAME] with a name for the key file.

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

Provide authentication credentials to your application code by setting the environment variable GOOGLE_APPLICATION_CREDENTIALS. Replace [PATH] with the file path of the JSON file that contains your service account key, and [FILE_NAME] with the filename. This variable only applies to your current shell session, so if you open a new session, set the variable again.

Linux or macOS

export GOOGLE_APPLICATION_CREDENTIALS="[PATH]"

For example:

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

Windows

With PowerShell:

$env:GOOGLE_APPLICATION_CREDENTIALS="[PATH]"

For example:

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

With command prompt:

set GOOGLE_APPLICATION_CREDENTIALS=[PATH]

Using the client library

The following example shows how to use the client library.

C#

Before trying this sample, follow the C# setup instructions in Setting Up a C# Development Environment . For more information, see the Datastore mode C# API reference documentation .

View on GitHub Feedback

using Google.Cloud.Datastore.V1;

namespace GoogleCloudSamples
{
    public class QuickStart
    {
        public static void Main(string[] args)
        {
            // Your Google Cloud Platform project ID
            string projectId = "YOUR-PROJECT-ID";

            // Instantiates a client
            DatastoreDb db = DatastoreDb.Create(projectId);

            // The kind for the new entity
            string kind = "Task";
            // The name/ID for the new entity
            string name = "sampletask1";
            KeyFactory keyFactory = db.CreateKeyFactory(kind);
            // The Cloud Datastore key for the new entity
            Key key = keyFactory.CreateKey(name);

            var task = new Entity
            {
                Key = key,
                ["description"] = "Buy milk"
            };
            using (DatastoreTransaction transaction = db.BeginTransaction())
            {
                // Saves the task
                transaction.Upsert(task);
                transaction.Commit();

                Console.WriteLine($"Saved {task.Key.Path[0].Name}: {(string)task["description"]}");
            }
        }
    }
}

Go

To use this sample, prepare your machine for Go development, and complete the Datastore mode quickstart. For more information, see the Datastore mode Go API reference documentation .

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// Sample datastore-quickstart fetches an entity from Google Cloud Datastore.
package main

import (
	"context"
	"fmt"
	"log"

	"cloud.google.com/go/datastore"
)

type Task struct {
	Description string
}

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

	// Set your Google Cloud Platform project ID.
	projectID := "YOUR_PROJECT_ID"

	// Creates a client.
	client, err := datastore.NewClient(ctx, projectID)
	if err != nil {
		log.Fatalf("Failed to create client: %v", err)
	}

	// Sets the kind for the new entity.
	kind := "Task"
	// Sets the name/ID for the new entity.
	name := "sampletask1"
	// Creates a Key instance.
	taskKey := datastore.NameKey(kind, name, nil)

	// Creates a Task instance.
	task := Task{
		Description: "Buy milk",
	}

	// Saves the new entity.
	if _, err := client.Put(ctx, taskKey, &task); err != nil {
		log.Fatalf("Failed to save task: %v", err)
	}

	fmt.Printf("Saved %v: %v\n", taskKey, task.Description)
}

Java

Before trying this sample, follow the Java setup instructions in Setting Up a Java Development Environment . For more information, see the Datastore mode Java API reference documentation .

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// Imports the Google Cloud client library
import com.google.cloud.datastore.Datastore;
import com.google.cloud.datastore.DatastoreOptions;
import com.google.cloud.datastore.Entity;
import com.google.cloud.datastore.Key;

public class QuickstartSample {
  public static void main(String... args) throws Exception {
    // Instantiates a client
    Datastore datastore = DatastoreOptions.getDefaultInstance().getService();

    // The kind for the new entity
    String kind = "Task";
    // The name/ID for the new entity
    String name = "sampletask1";
    // The Cloud Datastore key for the new entity
    Key taskKey = datastore.newKeyFactory().setKind(kind).newKey(name);

    // Prepares the new entity
    Entity task = Entity.newBuilder(taskKey)
        .set("description", "Buy milk")
        .build();

    // Saves the entity
    datastore.put(task);

    System.out.printf("Saved %s: %s%n", task.getKey().getName(), task.getString("description"));

    //Retrieve entity
    Entity retrieved = datastore.get(taskKey);

    System.out.printf("Retrieved %s: %s%n", taskKey.getName(), retrieved.getString("description"));

  }
}

Node.js

Before trying this sample, follow the Node.js setup instructions in Setting Up a Node.js Development Environment . For more information, see the Datastore mode Node.js API reference documentation .

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

async function quickStart() {
  // Your Google Cloud Platform project ID
  const projectId = 'YOUR_PROJECT_ID';

  // Creates a client
  const datastore = new Datastore({
    projectId: projectId,
  });

  // The kind for the new entity
  const kind = 'Task';
  // The name/ID for the new entity
  const name = 'sampletask1';
  // The Cloud Datastore key for the new entity
  const taskKey = datastore.key([kind, name]);

  // Prepares the new entity
  const task = {
    key: taskKey,
    data: {
      description: 'Buy milk',
    },
  };

  // Saves the entity
  await datastore.save(task);
  console.log(`Saved ${task.key.name}: ${task.data.description}`);
}
quickStart().catch(console.error);

PHP

To use this sample, prepare your machine for PHP development, and complete the Datastore mode quickstart. For more information, see the Datastore mode PHP API reference documentation .

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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\Datastore\DatastoreClient;

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

# Instantiates a client
$datastore = new DatastoreClient([
    'projectId' => $projectId
]);

# The kind for the new entity
$kind = 'Task';

# The name/ID for the new entity
$name = 'sampletask1';

# The Cloud Datastore key for the new entity
$taskKey = $datastore->key($kind, $name);

# Prepares the new entity
$task = $datastore->entity($taskKey, ['description' => 'Buy milk']);

# Saves the entity
$datastore->upsert($task);

echo 'Saved ' . $task->key() . ': ' . $task['description'] . PHP_EOL;

Python

Before trying this sample, follow the Python setup instructions in Setting Up a Python Development Environment . For more information, see the Datastore mode Python API reference documentation .

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# Imports the Google Cloud client library
from google.cloud import datastore

# Instantiates a client
datastore_client = datastore.Client()

# The kind for the new entity
kind = 'Task'
# The name/ID for the new entity
name = 'sampletask1'
# The Cloud Datastore key for the new entity
task_key = datastore_client.key(kind, name)

# Prepares the new entity
task = datastore.Entity(key=task_key)
task['description'] = 'Buy milk'

# Saves the entity
datastore_client.put(task)

print('Saved {}: {}'.format(task.key.name, task['description']))

Ruby

Before trying this sample, follow the Ruby setup instructions in Setting Up a Ruby Development Environment . For more information, see the Datastore mode Ruby API reference documentation .

View on GitHub Feedback

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

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

# Instantiates a client
datastore = Google::Cloud::Datastore.new project: project_id

# The kind for the new entity
kind = "Task"
# The name/ID for the new entity
name = "sampletask1"
# The Cloud Datastore key for the new entity
task_key = datastore.key kind, name

# Prepares the new entity
task = datastore.entity task_key do |t|
  t["description"] = "Buy milk"
end

# Saves the entity
datastore.save task

puts "Saved #{task.key.name}: #{task['description']}"

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

Dependency on App Engine application

If you are using a Google Cloud library to access Datastore mode, your Cloud project requires an active App Engine application. Open the App Engine dashboard and confirm your Cloud project has an active App Engine app. Create an App Engine app if needed. The app must not be disabled.

Google App Engine Standard Environment Client Libraries

Integrate Datastore mode with your App Engine Standard Environment applications by using the App Engine client libraries.

Language	Library
Go	Google App Engine SDK for Go
Java	Google App Engine SDK for Java
Python 2	Google Datastore NDB Client Library
Python 3	Google Cloud Datastore client library.

Note: For App Engine applications that are written in Python 2, the Google Datastore DB Client Library is no longer recommended; use the Google Datastore NDB Client Library instead.

Third party Datastore API client libraries

In addition to the Google-supported client libraries listed in the tables above, a set of third-party libraries are available.

Language	Library
Java	Objectify
Java	Catatumbo
PHP	Datastore Library for PHP
Node.js	js-data-cloud-datastore