Azure Storage Tables: How-to Guide

Introduction to Azure Storage Tables

Azure Table Storage is a NoSQL key-attribute store that allows you to store large amounts of structured, non-relational data. It's ideal for applications that require flexible data schemas and fast access to data. This guide will walk you through the essential operations for managing your Azure Storage Tables.

Prerequisites

Before you begin, ensure you have the following:

• An Azure Subscription.
• An Azure Storage Account.
• Appropriate permissions to manage the storage account.

Creating Tables

Tables are the fundamental containers for your data. You can create them using several methods.

Using the Azure Portal

1. Navigate to your Storage Account in the Azure portal.
2. Under "Data storage", select "Tables".
3. Click "+ Table".
4. Enter a unique table name (e.g., MyApplicationData). Table names must follow specific naming conventions (alphanumeric, start with a letter, 3-63 characters).
5. Click "OK".

Using Azure CLI

Use the following Azure CLI command:

az storage table create --name MyNewTable --account-name  --account-key 

Replace <your-storage-account-name> and <your-storage-account-key> with your actual storage account name and key.

Using SDKs

You can also create tables programmatically using Azure SDKs for various languages (e.g., .NET, Python, Java, Node.js).

Example using Azure SDK for Python:

from azure.storage.table import TableServiceClient

service_client = TableServiceClient.from_connection_string("YOUR_CONNECTION_STRING")
table = service_client.create_table("MyProgrammaticTable")
print(f"Table '{table.table_name}' created.")

Managing Entities

Entities are the individual records within a table. Each entity is a set of properties (name-value pairs).

Inserting Entities

An entity requires a PartitionKey and a RowKey to uniquely identify it. The Timestamp is automatically managed by Azure.

from azure.storage.table import TableService, Entity

table_service = TableService(account_name='your_account_name', account_key='your_account_key')

entity = {
    'PartitionKey': 'Customers',
    'RowKey': 'user123',
    'Name': 'Alice Wonderland',
    'Email': 'alice@example.com',
    'Age': 30
}

table_service.insert_entity('MyApplicationData', entity)
print("Entity inserted successfully.")

Querying Entities

You can query entities based on PartitionKey, RowKey, and other properties. OData filter expressions are supported.

from azure.storage.table import TableService, Entity

table_service = TableService(account_name='your_account_name', account_key='your_account_key')

# Query all entities in the 'Customers' partition
entities = table_service.query_entities('MyApplicationData', "PartitionKey eq 'Customers'")
for entity in entities:
    print(f"Name: {entity.Name}, Email: {entity.Email}")

# Query a specific entity by PartitionKey and RowKey
specific_entity = table_service.get_entity('MyApplicationData', 'Customers', 'user123')
print(f"Found entity: {specific_entity}")

# Query with a filter on another property
old_customers = table_service.query_entities('MyApplicationData', "PartitionKey eq 'Customers' and Age gt 25")
for customer in old_customers:
    print(f"Older customer: {customer.Name}")

Updating Entities

You can update an entity using insert_or_replace_entity (replaces if exists, inserts if not) or update_entity (updates only if it exists).

from azure.storage.table import TableService, Entity

table_service = TableService(account_name='your_account_name', account_key='your_account_key')

# Example using insert_or_replace_entity
updated_entity_data = {
    'PartitionKey': 'Customers',
    'RowKey': 'user123',
    'Name': 'Alice W. Smith',
    'Email': 'alice.smith@example.com',
    'Age': 31,
    'City': 'New York' # Adding a new property
}

table_service.insert_or_replace_entity('MyApplicationData', updated_entity_data)
print("Entity updated or inserted.")

Deleting Entities

Delete an entity by specifying its PartitionKey and RowKey.

from azure.storage.table import TableService

table_service = TableService(account_name='your_account_name', account_key='your_account_key')

table_service.delete_entity('MyApplicationData', 'Customers', 'user123')
print("Entity deleted.")

Understanding Partitions and Rows

PartitionKey: Entities with the same PartitionKey are co-located within the same partition. This is crucial for query performance and transaction guarantees. Design your PartitionKey to group logically related entities.

RowKey: Within a partition, entities are sorted by their RowKey. This allows for efficient range queries. Typically, you'd use a GUID or a unique identifier.

Performance Considerations

• Partition Key Design: Use a PartitionKey that distributes data evenly across partitions to avoid hot spots.
• Query Efficiency: Querying by PartitionKey and RowKey (especially a range) is the fastest. Filters on other properties can be less performant.
• Batch Operations: Use batch operations for inserting, updating, or deleting multiple entities within the same partition.
• Entity Size: Keep entities relatively small. The maximum size of an entity is 1 MB.

Security

Secure access to your Table Storage using:

• Shared Access Signatures (SAS): Grant limited, time-bound access to tables or entities.
• Access Control Lists (ACLs): Manage permissions at the table level.
• Azure AD Integration: Use Azure Active Directory for role-based access control.

Best Practices

• Choose appropriate data types for your properties.
• Implement robust error handling for all operations.
• Monitor storage metrics for performance and cost.
• Regularly review and manage your data lifecycle.
• Consider using Azure Cosmos DB for more complex querying or transactional needs if Table Storage becomes a bottleneck.