Azure Functions

Table Storage Input Bindings

Table storage input bindings allow you to read data from an Azure Table Storage table directly into your Azure Function. This is a convenient way to access structured NoSQL data without writing explicit SDK code.

Supported Types

You can bind to the following types when using a Table Storage input binding:

• string: Reads a single entity as a JSON string.
• dynamic (C#/PowerShell): Reads a single entity as a dynamic object.
• T (where T is a POCO class in C#): Reads a single entity and deserializes it into an object of type T. The properties of your class must match the column names in the table.
• IEnumerable (C#): Reads multiple entities.
• IQueryable (C#): Allows for more complex querying using LINQ.
• CloudTable: Provides access to the underlying Azure Table Storage SDK object.

Configuration

Table storage input bindings are configured in the function.json file. The primary parameters are:

• type: Set to table.
• name: The name of the parameter in your function code that will hold the data.
• tableName: The name of the Azure Table Storage table to read from.
• connection: The name of the application setting that contains the Azure Storage connection string.
• partitionKey (optional): Specifies the partition to query.
• rowKey (optional): Specifies the row within the partition to retrieve.
• filter (optional): Allows you to specify an OData filter expression for more advanced querying.

Example function.json

{
  "bindings": [
    {
      "name": "product",
      "type": "table",
      "tableName": "Products",
      "partitionKey": "{category}",
      "rowKey": "{productId}",
      "connection": "AzureWebJobsStorage",
      "direction": "in"
    },
    {
      "name": "outputQueueItem",
      "type": "queue",
      "queueName": "output-messages",
      "connection": "AzureWebJobsStorage",
      "direction": "out"
    }
  ],
  "disabled": false
}

C# Example

This example shows a C# function that reads a product from Table Storage based on route parameters (e.g., /api/products/{category}/{productId}).

using Microsoft.Azure.WebJobs;
using Microsoft.Extensions.Logging;

public static class GetProduct
{
    public static class Product
    {
        public string PartitionKey { get; set; }
        public string RowKey { get; set; }
        public string Name { get; set; }
        public decimal Price { get; set; }
    }

    [FunctionName("GetProduct")]
    public static void Run(
        [HttpTrigger(AuthorizationLevel.Function, "get", Route = "products/{category}/{productId}")] HttpRequest req,
        string category,
        string productId,
        [Table("Products", partitionKey = "{category}", rowKey = "{productId}", Connection = "AzureWebJobsStorage")] Product product,
        ILogger log)
    {
        if (product == null)
        {
            log.LogWarning($"Product not found: Category={category}, ProductId={productId}");
            // Handle not found case, e.g., return a 404
            return;
        }

        log.LogInformation($"Retrieved product: {product.Name}");
        // Process the product data
        // ...
    }
}

PowerShell Example

A PowerShell function reading a single entity.

param($req, $log)

$category = $req.Query.category
$productId = $req.Query.productId

# Assuming 'product' is defined in function.json as an input binding
# Example function.json:
# {
#   "bindings": [
#     {
#       "name": "product",
#       "type": "table",
#       "tableName": "Products",
#       "partitionKey": "{category}",
#       "rowKey": "{productId}",
#       "connection": "AzureWebJobsStorage",
#       "direction": "in"
#     }
#   ], ...
# }

if ($product) {
    $log.LogInformation("Retrieved product: $($product.Name)")
    # Output the product details
    Push-OutputBinding -Name resp -Value ([HttpResponseContext]@{
        StatusCode = 200
        Body = $product | ConvertTo-Json
    })
} else {
    $log.LogWarning("Product not found.")
    Push-OutputBinding -Name resp -Value ([HttpResponseContext]@{
        StatusCode = 404
        Body = "Product not found"
    })
}