Beginners Guide for Azure CosmosDB

CosmosDB is a globally distributed database which can be used to build highly scalable and reliable applications. It supports document, key-value, wide-column, and graph databases. CosmosDB is a schema-free database. Developers don’t need to worry about the schema of the database. Another cool feature is index management. It automatically indexes the data. It supports Multi-API for accessing the data. Users can access the data using SQL, Gremlin, Cassandra, Table, and MongoDB APIs. Pricing is based on data storage and throughput. Throughput can be changed dynamically also which is another advantage of CosmosDB. Dynamic throughput can be used to reduce costs.

Demo Time:
Now without wasting our time, let’s jump into the azure portal and start playing with CosmosDB.
1. Open Azure Portal and create a new resource
2. From the menu select Azure Cosmos DB
3. Enter the basic setting into the page and press Review+Create

https://www.dropbox.com/s/spk123qte9bjmt3/Screen Shot 2019-11-28 at 8.17.48 PM.png?dl=0

Now let’s create a container and collection and start putting data into it.
1. Open the created CosmosDB database and go to Data Explorer
2. Now click on New Container. Inside the popup fill all the details like database id, throughput, partition key, etc. and press OK. Later we’ll see how we can dynamically change the throughput.
3. Now inside the created database, you can see a container. Expand it and click on Items, then New Item.
4. Inside it create a JSON object

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{
  "id": "1",
  "category": "development",
  "name": "blog",
  "description": "Lorem ipsum"
}

Now let’s try to create containers and documents using Python SQL API.
P.S. For this while creating the CosmosDB account we need to select SQL API in the basic settings page.

1. First, we need to install Azure Cosmos DB SQL API client library for Python
   pip install azure-cosmos

2. Now get the Endpoint URI and Primary Key for the database. For that open the cosmos DB account in the Azure portal and go to QuickStart.

3. Import cosmos_client from the Python SQL library
   import azure.cosmos.cosmos_client as cosmos_client

4. Now initialize the cosmos client

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config = {
  'ENDPOINT': 'https://YOUR_DB_NAME.documents.azure.com:443/',
  'PRIMARYKEY': 'PRIMARY_KEY',
  'DATABASE': 'CosmosDatabase'
}

# Initialize the Cosmos client
client = cosmos_client.CosmosClient(url_connection = config['ENDPOINT'], auth = {
  'masterKey': config['PRIMARYKEY']
})

5. Create a database

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db = client.CreateDatabase({
  'id': config['DATABASE']
})
db_link = db['_self']

6. Create a container

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options = {
  'offerThroughput': 10000
}

container_definition = {
  'id': collection_name
}
container = client.CreateContainer(db_link, container_definition, options)
coll_link = container['_self']

7. Create a document in the container

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document = {
  'id': 1,
  'name': 'test_data',
  'description': 'Container Item'
}
client.CreateItem(coll_link, document)

Here is the final code:

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import azure.cosmos.cosmos_client as cosmos_client
config = {
  'ENDPOINT': 'https://YOUR_DB_NAME.documents.azure.com:443/',
  'PRIMARYKEY': 'PRIMARY_KEY',
  'DATABASE': 'CosmosDatabase'
}

# Initialize the Cosmos client
client = cosmos_client.CosmosClient(url_connection = config['ENDPOINT'], auth = {
  'masterKey': config['PRIMARYKEY']
})

#create db
try:
db = client.CreateDatabase({
  'id': config['DATABASE']
})
db_link = db['_self']
except Exception as e:
  #
if DB is already there
db_id = config['DATABASE']
db_query = "select * from r where r.id = '{0}'".format(db_id)
db = list(client.QueryDatabases(db_query))[0]
db_link = db['_self']

# Create container options
options = {
  'offerThroughput': 10000
}

container_definition = {
  'id': collection_name
}

try:
# Create a container
container = client.CreateContainer(db_link, container_definition, options)
coll_link = container['_self']
except Exception as e:
  #
if collection is already there
coll_id = collection_name
coll_query = "select * from r where r.id = '{0}'".format(coll_id)
coll = list(client.QueryContainers(db_link, coll_query))[0]
coll_link = coll['_self']

#insert data
document = {
  'id': 1,
  'name': 'test_data',
  'description': 'Container Item'
}
client.CreateItem(coll_link, document)

I hope you guys liked this post. In our next blog, we’ll go deeper into Azure cosmos DB and try few more techniques. Till then happy coding :)

References:

1. Azure Cosmos Python

2. Microsoft Docs

3. Getting started with Azure Cosmos DB