How to Use Azure Table Storage

Azure Table storage is a NoSQL key-attribute store that you can use to store large amounts of structured, non-relational data. It's a cost-effective way to store data that requires flexible schemas. This guide will walk you through the fundamental operations for using Azure Table storage.

Prerequisites

An Azure Subscription.
An Azure Storage Account.
Install the Azure SDK for your preferred language (e.g., .NET, Python, Java, Node.js).

Creating a Table

Before you can store data, you need to create a table. Tables in Azure Table storage are schemaless, meaning you don't define column types upfront. Each entity within a table can have a different set of properties.

Using the Azure SDK (.NET Example)


using Azure.Data.Tables;

string connectionString = "YOUR_AZURE_STORAGE_CONNECTION_STRING";
string tableName = "MyProducts";

TableServiceClient tableServiceClient = new TableServiceClient(connectionString);
TableClient tableClient = await tableServiceClient.CreateTableIfNotExistsAsync(tableName);

Console.WriteLine($"Table '{tableName}' created or already exists.");

Adding an Entity to a Table

An entity is a record in a table, similar to a row in a relational database. Each entity must have two properties: PartitionKey and RowKey. These two properties together uniquely identify an entity.

PartitionKey: Groups entities that share a common partition. All entities in the same partition are stored together.
RowKey: Uniquely identifies an entity within a partition.

Using the Azure SDK (.NET Example)


using Azure;
using Azure.Data.Tables;

// Assume tableClient is already created as shown above

var productEntity = new TableEntity("Electronics", "ProductID123")
{
    ["Name"] = "Laptop",
    ["Price"] = 1200.50m,
    ["Category"] = "Computers",
    ["Stock"] = 50,
    ["IsAvailable"] = true
};

await tableClient.AddEntityAsync(productEntity);

Console.WriteLine("Entity added successfully.");

Querying Entities

You can retrieve entities from a table using various query methods. You can filter by partition key, row key, or other properties.

Retrieving a Single Entity


using Azure;
using Azure.Data.Tables;

// Assume tableClient is already created

Response<TableEntity> response = await tableClient.GetEntityAsync<TableEntity>("Electronics", "ProductID123");
TableEntity entity = response.Value;

Console.WriteLine($"Name: {entity["Name"]}, Price: {entity["Price"]}");

Retrieving Multiple Entities (Query)


using Azure;
using Azure.Data.Tables;

// Assume tableClient is already created

string filter = "Category eq 'Computers'";
var queryResults = tableClient.QueryAsync<TableEntity>(filter: filter);

await foreach (var page in queryResults.AsPages())
{
    foreach (TableEntity entity in page.Values)
    {
        Console.WriteLine($"PartitionKey: {entity.PartitionKey}, RowKey: {entity.RowKey}, Name: {entity["Name"]}");
    }
}

Updating an Entity

You can update existing entities. If the entity does not exist, it can be inserted.

Using the Azure SDK (.NET Example)


using Azure;
using Azure.Data.Tables;

// Assume tableClient is already created and entity exists

var updatedEntity = new TableEntity("Electronics", "ProductID123")
{
    ["Price"] = 1150.75m,
    ["Stock"] = 45
};

await tableClient.UpsertEntityAsync(updatedEntity, TableUpdateMode.Replace); // Use Replace to overwrite or Merge to update specific properties

Console.WriteLine("Entity updated successfully.");

Deleting an Entity

You can delete an entity by providing its partition key and row key.

Using the Azure SDK (.NET Example)


using Azure;
using Azure.Data.Tables;

// Assume tableClient is already created

await tableClient.DeleteEntityAsync("Electronics", "ProductID123");

Console.WriteLine("Entity deleted successfully.");

Deleting a Table

You can delete an entire table. This action is irreversible.

Using the Azure SDK (.NET Example)


using Azure;
using Azure.Data.Tables;

// Assume tableClient is already created

await tableServiceClient.DeleteTableAsync(tableName);

Console.WriteLine($"Table '{tableName}' deleted successfully.");

Tip: When designing your table schema, consider how you will query your data. Choosing an effective PartitionKey can significantly improve query performance and reduce costs, especially for large datasets.

Note: Azure Table storage is designed for structured NoSQL data. For semi-structured or unstructured data, consider Azure Blob Storage.

Important: Always secure your storage account connection strings. Do not embed them directly in client-side code.

Azure Documentation