Quickstart: Azure Cosmos DB for Table for .NET
APPLIES TO: Table
This quickstart shows how to get started with the Azure Cosmos DB for Table from a .NET application. The Azure Cosmos DB for Table is a schemaless data store allowing applications to store structured table data in the cloud. You learn how to create tables, rows, and perform basic tasks within your Azure Cosmos DB resource using the Azure.Data.Tables Package (NuGet).
Note
The example code snippets are available on GitHub as a .NET project.
API for Table reference documentation | Azure.Data.Tables Package (NuGet)
Prerequisites
- An Azure account with an active subscription. Create an account for free.
- GitHub account
- An Azure account with an active subscription. Create an account for free.
- Azure Developer CLI
- Docker Desktop
Setting up
Deploy this project's development container to your environment. Then, use the Azure Developer CLI (azd) to create an Azure Cosmos DB for Table account and deploy a containerized sample application. The sample application uses the client library to manage, create, read, and query sample data.
Important
GitHub accounts include an entitlement of storage and core hours at no cost. For more information, see included storage and core hours for GitHub accounts.
Open a terminal in the root directory of the project.
Authenticate to the Azure Developer CLI using
azd auth login
. Follow the steps specified by the tool to authenticate to the CLI using your preferred Azure credentials.azd auth login
Use
azd init
to initialize the project.azd init
During initialization, configure a unique environment name.
Tip
The environment name will also be used as the target resource group name. For this quickstart, consider using
msdocs-cosmos-db
.Deploy the Azure Cosmos DB account using
azd up
. The Bicep templates also deploy a sample web application.azd up
During the provisioning process, select your subscription and desired location. Wait for the provisioning process to complete. The process can take approximately five minutes.
Once the provisioning of your Azure resources is done, a URL to the running web application is included in the output.
Deploying services (azd deploy) (✓) Done: Deploying service web - Endpoint: <https://[container-app-sub-domain].azurecontainerapps.io> SUCCESS: Your application was provisioned and deployed to Azure in 5 minutes 0 seconds.
Use the URL in the console to navigate to your web application in the browser. Observe the output of the running app.
Install the client library
The client library is available through NuGet, as the Microsoft.Azure.Cosmos
package.
Open a terminal and navigate to the
/src/web
folder.cd ./src/web
If not already installed, install the
Azure.Data.Tables
package usingdotnet add package
.dotnet add package Azure.Data.Tables --version 12.*
Also, install the
Azure.Identity
package if not already installed.dotnet add package Azure.Identity --version 1.*
Open and review the src/web/Cosmos.Samples.Table.Quickstart.Web.csproj file to validate that the
Azure.Data.Tables
andAzure.Identity
entries both exist.
Object model
Name | Description |
---|---|
TableServiceClient | This class is the primary client class and is used to manage account-wide metadata or databases. |
TableClient | This class represents the client for a table within the account. |
Code examples
The sample code in the template uses a table named cosmicworks-products
. The table contains details such as name, category, quantity, a unique identifier, and a sale flag for each product.
Authenticate the clients
Application requests to most Azure services must be authorized. Use the DefaultAzureCredential
type as the preferred way to implement a passwordless connection between your applications and Azure Cosmos DB for NoSQL. DefaultAzureCredential
supports multiple authentication methods and determines which method should be used at runtime.
Important
You can also authorize requests to Azure services using passwords, connection strings, or other credentials directly. However, this approach should be used with caution. Developers must be diligent to never expose these secrets in an unsecure location. Anyone who gains access to the password or secret key is able to authenticate to the database service. DefaultAzureCredential
offers improved management and security benefits over the account key to allow passwordless authentication without the risk of storing keys.
This sample creates a new instance of the TableServiceClient
and TableClient
classes and authenticates using a DefaultAzureCredential
instance.
DefaultAzureCredential credential = new();
TableServiceClient serviceClient = new(
endpoint: new Uri("<azure-cosmos-db-table-account-endpoint>"),
tokenCredential: credential
);
TableClient client = serviceClient.GetTableClient(
tableName: "<azure-cosmos-db-table-name>"
);
Create an item
The easiest way to create a new item in a table is to create a class that implements the ITableEntity
interface. You can then add your own properties to the class to populate columns of data in that table row.
public record Product : ITableEntity
{
public string RowKey { get; set; } = $"{Guid.NewGuid()}";
public string PartitionKey { get; set; } = String.Empty;
public string Name { get; set; } = String.Empty;
public int Quantity { get; set; } = 0;
public decimal Price { get; set; } = 0.0m;
public bool Clearance { get; set; } = false;
public ETag ETag { get; set; } = ETag.All;
public DateTimeOffset? Timestamp { get; set; }
};
Create an item in the collection using the Product
class by calling TableClient.AddEntityAsync<T>
.
Product entity = new()
{
RowKey = "68719518391",
PartitionKey = "gear-surf-surfboards",
Name = "Surfboard",
Quantity = 10,
Price = 300.00m,
Clearance = true
};
Response response = await client.UpsertEntityAsync<Product>(
entity: entity,
mode: TableUpdateMode.Replace
);
Get an item
You can retrieve a specific item from a table using the TableClient.GetEntityAsync<T>
method. Provide the partitionKey
and rowKey
as parameters to identify the correct row to perform a quick point read of that item.
Response<Product> response = await client.GetEntityAsync<Product>(
rowKey: "68719518391",
partitionKey: "gear-surf-surfboards"
);
Query items
After you insert an item, you can also run a query to get all items that match a specific filter by using the TableClient.Query<T>
method. This example filters products by category using Linq syntax, which is a benefit of using typed ITableEntity
models like the Product
class.
Note
You can also query items using OData syntax. You can see an example of this approach in the Query Data tutorial.
string category = "gear-surf-surfboards";
AsyncPageable<Product> results = client.QueryAsync<Product>(
product => product.PartitionKey == category
);
Parse the paginated results of the query by looping through each page of results using asynchronous loop to determine if there are any results left at the start of each loop.
Clean up resources
When you no longer need the Azure Cosmos DB for Table account, you can delete the corresponding resource group.
Use the az group delete
command to delete the resource group.
az group delete --name $resourceGroupName