Azure Cosmos DB: Build a DocumentDB API app with Python and the Azure portal

Azure Cosmos DB is Microsoft’s globally distributed multi-model database service. You can quickly create and query document, key/value, and graph databases, all of which benefit from the global distribution and horizontal scale capabilities at the core of Azure Cosmos DB.

This quick start demonstrates how to create an Azure Cosmos DB account, document database, and collection using the Azure portal. You then build and run a console app built on the DocumentDB Python API.

Prerequisites

  • Before you can run this sample, you must have the following prerequisites:
    • If you don’t already have Visual Studio 2017 installed, you can download and use the free Visual Studio 2017 Community Edition. Make sure that you enable Azure development during the Visual Studio setup.
    • Python Tools for Visual Studio from GitHub. This tutorial uses Python Tools for VS 2015.
    • Python 2.7 from python.org

If you don't have an Azure subscription, create a free account before you begin.

Alternatively, you can Try Azure Cosmos DB for free without an Azure subscription, free of charge and commitments. Or you can use the Azure Cosmos DB Emulator for this tutorial with a URI of https://localhost:8081 and a key of

C2y6yDjf5/R+ob0N8A7Cgv30VRDJIWEHLM+4QDU5DE2nQ9nDuVTqobD4b8mGGyPMbIZnqyMsEcaGQy67XIw/Jw==

Create a database account

  1. In a new window, sign in to the Azure portal.
  2. In the left pane, click New, click Databases, and then under Azure Cosmos DB, click Create.

    The Azure portal Databases pane

  3. On the New account blade, specify the configuration that you want for this Azure Cosmos DB account.

    With Azure Cosmos DB, you can choose one of four programming models: Gremlin (graph), MongoDB, SQL (DocumentDB), and Table (key-value), each which currently require a separate account.

    In this quick-start article we program against the DocumentDB API, so choose SQL (DocumentDB) as you fill out the form. If you have graph data for a social media app, or key/value (table) data, or data migrated from a MongoDB app, realize that Azure Cosmos DB can provide a highly available, globally distributed database service platform for all your mission-critical applications.

    Complete the fields on the New account blade, using the information in the following screenshot as a guide- your values may be different than the values in the screenshot.

    The new account blade for Azure Cosmos DB

    Setting Suggested value Description
    ID Unique value A unique name that identifies this Azure Cosmos DB account. Because documents.azure.com is appended to the ID that you provide to create your URI, use a unique but identifiable ID. The ID can contain only lowercase letters, numbers, and the hyphen (-) character, and it must contain 3 to 50 characters.
    API SQL (DocumentDB) We program against the DocumentDB API later in this article.
    Subscription Your subscription The Azure subscription that you want to use for this Azure Cosmos DB account.
    Resource Group The same value as ID The new resource-group name for your account. For simplicity, you can use the same name as your ID.
    Location The region closest to your users The geographic location in which to host your Azure Cosmos DB account. Choose the location that's closest to your users to give them the fastest access to the data.
  4. Click Create to create the account.
  5. On the top toolbar, click the Notifications icon The notification icon to monitor the deployment process.

    The Azure portal Notifications pane

  6. When the Notifications window indicates the deployment succeeded, close the notification window and open the new account from the All Resources tile on the Dashboard.

    The Azure Cosmos DB account on the All Resources tile

Add a collection

You can now use the Data Explorer tool in the Azure portal to create a database and collection.

  1. In the Azure portal, in the left navigation menu, click Data Explorer (Preview).

  2. On the Data Explorer (Preview) blade, click New Collection, and then provide the following information:

    The Azure portal Data Explorer blade

    Setting Suggested value Description
    Database id Tasks The name for your new database. Database names must contain from 1 through 255 characters, and they cannot contain /, \, #, ?, or a trailing space.
    Collection id Items The name for your new collection. Collection names have the same character requirements as database IDs.
    Storage capacity Fixed (10 GB) Use the default value. This value is the storage capacity of the database.
    Throughput 400 RU Use the default value. If you want to reduce latency, you can scale up the throughput later.
    Partition key /category A partition key that distributes data evenly to each partition. Selecting the correct partition key is important in creating a performant collection. To learn more, see Designing for partitioning.
  3. After you've completed the form, click OK.

Data Explorer shows the new Database and collection.

Clone the sample application

Now let's clone a DocumentDB API app from github, set the connection string, and run it. You see how easy it is to work with data programmatically.

  1. Open a git terminal window, such as git bash, and cd to a working directory.

  2. Run the following command to clone the sample repository.

    git clone https://github.com/Azure-Samples/azure-cosmos-db-documentdb-python-getting-started.git
    

    Review the code

Let's make a quick review of what's happening in the app. Open the DocumentDBGetStarted.py file and you'll find that these lines of code create the Azure Cosmos DB resources.

  • The DocumentClient is initialized.

    # Initialize the Python DocumentDB client
    client = document_client.DocumentClient(config['ENDPOINT'], {'masterKey': config['MASTERKEY']})
    
  • A new database is created.

    # Create a database
    db = client.CreateDatabase({ 'id': config['DOCUMENTDB_DATABASE'] })
    
  • A new collection is created.

    # Create collection options
    options = {
        'offerEnableRUPerMinuteThroughput': True,
        'offerVersion': "V2",
        'offerThroughput': 400
    }
    
    # Create a collection
    collection = client.CreateCollection(db['_self'], { 'id': config['DOCUMENTDB_COLLECTION'] }, options)
    
  • Some documents are created.

    # Create some documents
    document1 = client.CreateDocument(collection['_self'],
        { 
            'id': 'server1',
            'Web Site': 0,
            'Cloud Service': 0,
            'Virtual Machine': 0,
            'name': 'some' 
        })
    
  • A query is performed using SQL

    # Query them in SQL
    query = { 'query': 'SELECT * FROM server s' }    
    
    options = {} 
    options['enableCrossPartitionQuery'] = True
    options['maxItemCount'] = 2
    
    result_iterable = client.QueryDocuments(collection['_self'], query, options)
    results = list(result_iterable);
    
    print(results)
    

Update your connection string

Now go back to the Azure portal to get your connection string information and copy it into the app.

  1. In the Azure portal, in your Azure Cosmos DB account, in the left navigation click Keys, and then click Read-write Keys. You'll use the copy buttons on the right side of the screen to copy the URI and Primary Key into the DocumentDBGetStarted.py file in the next step.

    View and copy an access key in the Azure portal, Keys blade

  2. In Open the DocumentDBGetStarted.py file.

  3. Copy your URI value from the portal (using the copy button) and make it the value of the endpoint key in DocumentDBGetStarted.py.

    config.ENDPOINT : "https://FILLME.documents.azure.com"

  4. Then copy your PRIMARY KEY value from the portal and make it the value of the config.MASTERKEY in DocumentDBGetStarted.py. You've now updated your app with all the info it needs to communicate with Azure Cosmos DB.

    config.MASTERKEY : "FILLME"

Run the app

  1. In Visual Studio, right-click on the project in Solution Explorer, select the current Python environment, then right click.

  2. Select Install Python Package, then type in pydocumentdb

  3. Run F5 to run the application. Your app displays in your browser.

You can now go back to Data Explorer and see query, modify, and work with this new data.

Review SLAs in the Azure portal

Now that your app is up and running, you'll want to ensure business continuity and watch user access to ensure high availability. You can use the Azure portal to review the availability, latency, throughput, and consistency of your collection.

Each graph that's associated with the Azure Cosmos DB Service Level Agreements (SLAs) provides a line that shows the quota required to meet the SLA and your actual usage. This information gives you a clear view into your database performance. Additional metrics, such as storage usage and number of requests per minute, are also included in the portal.

  • In the Azure portal, in the pane on the left, under Monitoring, select Metrics.

    Todo app with sample data

Clean up resources

If you're not going to continue to use this app, delete all resources created by this quickstart in the Azure portal with the following steps:

  1. From the left-hand menu in the Azure portal, click Resource groups and then click the name of the resource you created.
  2. On your resource group page, click Delete, type the name of the resource to delete in the text box, and then click Delete.

Next steps

In this quickstart, you've learned how to create an Azure Cosmos DB account, create a collection using the Data Explorer, and run an app. You can now import additional data to your Cosmos DB account.