Azure Tables input bindings for Azure Functions

An isolated worker process class library compiled C# function runs in a process isolated from the runtime.

An in-process class library is a compiled C# function runs in the same process as the Functions runtime.

The following example shows a C# function that reads a single table row. For every message sent to the queue, the function will be triggered.

The row key value {queueTrigger} binds the row key to the message metadata, which is the message string.

public class TableStorage
{
    public class MyPoco : Azure.Data.Tables.ITableEntity
    {
        public string Text { get; set; }

        public string PartitionKey { get; set; }
        public string RowKey { get; set; }
        public DateTimeOffset? Timestamp { get; set; }
        public ETag ETag { get; set; }
    }


    [FunctionName("TableInput")]
    public static void TableInput(
        [QueueTrigger("table-items")] string input, 
        [Table("MyTable", "MyPartition", "{queueTrigger}")] MyPoco poco, 
        ILogger log)
    {
        log.LogInformation($"PK={poco.PartitionKey}, RK={poco.RowKey}, Text={poco.Text}");
    }
}

Use a TableClient method parameter to read the table by using the Azure SDK. Here's an example of a function that queries an Azure Functions log table:

using Microsoft.Azure.WebJobs;
using Microsoft.Extensions.Logging;
using Azure.Data.Tables;
using System;
using System.Threading.Tasks;
using Azure;
namespace FunctionAppCloudTable2
{
    public class LogEntity : ITableEntity
    {
        public string OriginalName { get; set; }

        public string PartitionKey { get; set; }
        public string RowKey { get; set; }
        public DateTimeOffset? Timestamp { get; set; }
        public ETag ETag { get; set; }
    }
    public static class CloudTableDemo
    {
        [FunctionName("CloudTableDemo")]
        public static async Task Run(
            [TimerTrigger("0 */1 * * * *")] TimerInfo myTimer,
            [Table("AzureWebJobsHostLogscommon")] TableClient tableClient,
            ILogger log)
        {
            log.LogInformation($"C# Timer trigger function executed at: {DateTime.Now}");
            AsyncPageable<LogEntity> queryResults = tableClient.QueryAsync<LogEntity>(filter: $"PartitionKey eq 'FD2' and RowKey gt 't'");
            await foreach (LogEntity entity in queryResults)
            {
                log.LogInformation($"{entity.PartitionKey}\t{entity.RowKey}\t{entity.Timestamp}\t{entity.OriginalName}");
            }
        }
    }
}

For more information about how to use TableClient, see the Azure.Data.Tables API Reference.

The following example shows a C# function that reads a single table row. For every message sent to the queue, the function will be triggered.

The row key value {queueTrigger} binds the row key to the message metadata, which is the message string.

public class TableStorage
{
    public class MyPoco
    {
        public string PartitionKey { get; set; }
        public string RowKey { get; set; }
        public string Text { get; set; }
    }

    [FunctionName("TableInput")]
    public static void TableInput(
        [QueueTrigger("table-items")] string input, 
        [Table("MyTable", "MyPartition", "{queueTrigger}")] MyPoco poco, 
        ILogger log)
    {
        log.LogInformation($"PK={poco.PartitionKey}, RK={poco.RowKey}, Text={poco.Text}");
    }
}

Use a CloudTable method parameter to read the table by using the Azure Storage SDK. Here's an example of a function that queries an Azure Functions log table:

using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Host;
using Microsoft.Extensions.Logging;
using Microsoft.Azure.Cosmos.Table;
using System;
using System.Threading.Tasks;

namespace FunctionAppCloudTable2
{
    public class LogEntity : TableEntity
    {
        public string OriginalName { get; set; }
    }
    public static class CloudTableDemo
    {
        [FunctionName("CloudTableDemo")]
        public static async Task Run(
            [TimerTrigger("0 */1 * * * *")] TimerInfo myTimer, 
            [Table("AzureWebJobsHostLogscommon")] CloudTable cloudTable,
            ILogger log)
        {
            log.LogInformation($"C# Timer trigger function executed at: {DateTime.Now}");

            TableQuery<LogEntity> rangeQuery = new TableQuery<LogEntity>().Where(
                TableQuery.CombineFilters(
                    TableQuery.GenerateFilterCondition("PartitionKey", QueryComparisons.Equal, 
                        "FD2"),
                    TableOperators.And,
                    TableQuery.GenerateFilterCondition("RowKey", QueryComparisons.GreaterThan, 
                        "t")));

            // Execute the query and loop through the results
            foreach (LogEntity entity in 
                await cloudTable.ExecuteQuerySegmentedAsync(rangeQuery, null))
            {
                log.LogInformation(
                    $"{entity.PartitionKey}\t{entity.RowKey}\t{entity.Timestamp}\t{entity.OriginalName}");
            }
        }
    }
}

For more information about how to use CloudTable, see Get started with Azure Table storage.

If you try to bind to CloudTable and get an error message, make sure that you have a reference to the correct Storage SDK version.

The following example shows a C# function that reads a single table row. For every message sent to the queue, the function will be triggered.

The row key value {queueTrigger} binds the row key to the message metadata, which is the message string.

public class TableStorage
{
    public class MyPoco
    {
        public string PartitionKey { get; set; }
        public string RowKey { get; set; }
        public string Text { get; set; }
    }

    [FunctionName("TableInput")]
    public static void TableInput(
        [QueueTrigger("table-items")] string input, 
        [Table("MyTable", "MyPartition", "{queueTrigger}")] MyPoco poco, 
        ILogger log)
    {
        log.LogInformation($"PK={poco.PartitionKey}, RK={poco.RowKey}, Text={poco.Text}");
    }
}

The following example shows a C# function that reads multiple table rows where the MyPoco class derives from TableEntity.

public class TableStorage
{
    public class MyPoco : TableEntity
    {
        public string Text { get; set; }
    }

    [FunctionName("TableInput")]
    public static void TableInput(
        [QueueTrigger("table-items")] string input, 
        [Table("MyTable", "MyPartition")] IQueryable<MyPoco> pocos, 
        ILogger log)
    {
        foreach (MyPoco poco in pocos)
        {
            log.LogInformation($"PK={poco.PartitionKey}, RK={poco.RowKey}, Text={poco.Text}");
        }
    }
}

The following MyTableData class represents a row of data in the table:

public class MyTableData : Azure.Data.Tables.ITableEntity
{
    public string Text { get; set; }

    public string PartitionKey { get; set; }
    public string RowKey { get; set; }
    public DateTimeOffset? Timestamp { get; set; }
    public ETag ETag { get; set; }
}

The following function, which is started by a Queue Storage trigger, reads a row key from the queue, which is used to get the row from the input table. The expression {queueTrigger} binds the row key to the message metadata, which is the message string.

[Function("TableFunction")]
[TableOutput("OutputTable", Connection = "AzureWebJobsStorage")]
public static MyTableData Run(
    [QueueTrigger("table-items")] string input,
    [TableInput("MyTable", "<PartitionKey>", "{queueTrigger}")] MyTableData tableInput,
    FunctionContext context)
{
    var logger = context.GetLogger("TableFunction");

    logger.LogInformation($"PK={tableInput.PartitionKey}, RK={tableInput.RowKey}, Text={tableInput.Text}");

    return new MyTableData()
    {
        PartitionKey = "queue",
        RowKey = Guid.NewGuid().ToString(),
        Text = $"Output record with rowkey {input} created at {DateTime.Now}"
    };
}

The following Queue-triggered function returns the first 5 entities as an IEnumerable<T>, with the partition key value set as the queue message.

[Function("TestFunction")]
public static void Run([QueueTrigger("myqueue", Connection = "AzureWebJobsStorage")] string partition,
    [TableInput("inTable", "{queueTrigger}", Take = 5, Filter = "Text eq 'test'", 
    Connection = "AzureWebJobsStorage")] IEnumerable<MyTableData> tableInputs,
    FunctionContext context)
{
    var logger = context.GetLogger("TestFunction");
    logger.LogInformation(partition);
    foreach (MyTableData tableInput in tableInputs)
    {
        logger.LogInformation($"PK={tableInput.PartitionKey}, RK={tableInput.RowKey}, Text={tableInput.Text}");
    }
}

The Filter and Take properties are used to limit the number of entities returned.

The following MyTableData class represents a row of data in the table:

{
    var tableEntities = table.QueryAsync<TableEntity>(filter: $"RowKey eq '{rowKey}'");

    await foreach (TableEntity entity in tableEntities)
    {
        _logger.LogInformation("PK={pk}, RK={rk}, Text={t}", entity.PartitionKey, entity.RowKey, entity["Text"]);
    }

The following function, which is started by a Queue Storage trigger, reads a row key from the queue, which is used to get the row from the input table. The expression {queueTrigger} binds the row key to the message metadata, which is the message string.

namespace SampleApp
{
    public class TableFunction
    {
        private readonly ILogger<TableFunction> _logger;

        public TableFunction(ILogger<TableFunction> logger)
        {
            _logger = logger;
        }

        /// <summary>
        /// This function demonstrates binding to a single <see cref="TableClient"/>
        /// and using the client for output.
        /// </summary>
        [Function(nameof(TableFunction))]
        public async Task Run(
            [QueueTrigger("table-items")] string rowKey,

The following Queue-triggered function returns the first 5 entities as an IEnumerable<T>, with the partition key value set as the queue message.

[Function("TestFunction")]
public static void Run([QueueTrigger("myqueue", Connection = "AzureWebJobsStorage")] string partition,
    [TableInput("inTable", "{queueTrigger}", Take = 5, Filter = "Text eq 'test'", 
    Connection = "AzureWebJobsStorage")] IEnumerable<MyTableData> tableInputs,
    FunctionContext context)
{
    var logger = context.GetLogger("TestFunction");
    logger.LogInformation(partition);
    foreach (MyTableData tableInput in tableInputs)
    {
        logger.LogInformation($"PK={tableInput.PartitionKey}, RK={tableInput.RowKey}, Text={tableInput.Text}");
    }
}

The Filter and Take properties are used to limit the number of entities returned.

Functions version 1.x doesn't support isolated worker process.

import { app, input, InvocationContext } from '@azure/functions';

const tableInput = input.table({
    tableName: 'Person',
    partitionKey: 'Test',
    rowKey: '{queueTrigger}',
    connection: 'MyStorageConnectionAppSetting',
});

interface PersonEntity {
    PartitionKey: string;
    RowKey: string;
    Name: string;
}

export async function storageQueueTrigger1(queueItem: unknown, context: InvocationContext): Promise<void> {
    context.log('Node.js queue trigger function processed work item', queueItem);
    const person = <PersonEntity>context.extraInputs.get(tableInput);
    context.log('Person entity name: ' + person.Name);
}

app.storageQueue('storageQueueTrigger1', {
    queueName: 'myqueue-items',
    connection: 'MyStorageConnectionAppSetting',
    extraInputs: [tableInput],
    handler: storageQueueTrigger1,
});

TypeScript samples are not documented for model v3.

const { app, input } = require('@azure/functions');

const tableInput = input.table({
    tableName: 'Person',
    partitionKey: 'Test',
    rowKey: '{queueTrigger}',
    connection: 'MyStorageConnectionAppSetting',
});

app.storageQueue('storageQueueTrigger1', {
    queueName: 'myqueue-items',
    connection: 'MyStorageConnectionAppSetting',
    extraInputs: [tableInput],
    handler: (queueItem, context) => {
        context.log('Node.js queue trigger function processed work item', queueItem);
        const person = context.extraInputs.get(tableInput);
        context.log('Person entity name: ' + person.Name);
    },
});

{
  "bindings": [
    {
      "queueName": "myqueue-items",
      "connection": "MyStorageConnectionAppSetting",
      "name": "myQueueItem",
      "type": "queueTrigger",
      "direction": "in"
    },
    {
      "name": "personEntity",
      "type": "table",
      "tableName": "Person",
      "partitionKey": "Test",
      "rowKey": "{queueTrigger}",
      "connection": "MyStorageConnectionAppSetting",
      "direction": "in"
    }
  ],
  "disabled": false
}

The configuration section explains these properties.

Here's the JavaScript code:

module.exports = async function (context, myQueueItem) {
    context.log('Node.js queue trigger function processed work item', myQueueItem);
    context.log('Person entity name: ' + context.bindings.personEntity.Name);
};

import json
import azure.functions as func

app = func.FunctionApp()

@app.route(route="messages/{id}")
@app.table_input(arg_name="messageJSON",
                 connection="AzureWebJobsStorage",
                 table_name="messages",
                 row_key='{id}',
                 partition_key="message")
def table_in_binding(req: func.HttpRequest, messageJSON):
    message = json.loads(messageJSON)
    return func.HttpResponse(f"Table row: {messageJSON}")

With this simple binding, you can't programmatically handle a case in which no row that has a row key ID is found. For more fine-grained data selection, use the storage SDK.

Binding configuration in the function.json file:

{
  "scriptFile": "__init__.py",
  "bindings": [
    {
      "name": "messageJSON",
      "type": "table",
      "tableName": "messages",
      "partitionKey": "message",
      "rowKey": "{id}",
      "connection": "AzureWebJobsStorage",
      "direction": "in"
    },
    {
      "authLevel": "function",
      "type": "httpTrigger",
      "direction": "in",
      "name": "req",
      "methods": [
        "get",
        "post"
      ],
      "route": "messages/{id}"
    },
    {
      "type": "http",
      "direction": "out",
      "name": "$return"
    }
  ],
  "disabled": false
}

Python code in the __init__.py file:

import json

import azure.functions as func

def main(req: func.HttpRequest, messageJSON) -> func.HttpResponse:

    message = json.loads(messageJSON)
    return func.HttpResponse(f"Table row: {messageJSON}")

With this simple binding, you can't programmatically handle a case in which no row that has a row key ID is found. For more fine-grained data selection, use the storage SDK.

In C# class libraries, the TableInputAttribute supports the following properties:

In C# class libraries, the TableAttribute supports the following properties:

The attribute's constructor takes the table name, partition key, and row key, as shown in the following example:

[FunctionName("TableInput")]
public static void Run(
    [QueueTrigger("table-items")] string input, 
    [Table("MyTable", "Http", "{queueTrigger}")] MyPoco poco, 
    ILogger log)
{
    ...
}

You can set the Connection property to specify the connection to the table service, as shown in the following example:

[FunctionName("TableInput")]
public static void Run(
    [QueueTrigger("table-items")] string input, 
    [Table("MyTable", "Http", "{queueTrigger}", Connection = "StorageConnectionAppSetting")] MyPoco poco, 
    ILogger log)
{
    ...
}

While the attribute takes a Connection property, you can also use the StorageAccountAttribute to specify a storage account connection. You can do this when you need to use a different storage account than other functions in the library. The constructor takes the name of an app setting that contains a storage connection string. The attribute can be applied at the parameter, method, or class level. The following example shows class level and method level:

[StorageAccount("ClassLevelStorageAppSetting")]
public static class AzureFunctions
{
    [FunctionName("StorageTrigger")]
    [StorageAccount("FunctionLevelStorageAppSetting")]
    public static void Run( //...
{
    ...
}

The storage account to use is determined in the following order:

• The trigger or binding attribute's Connection property.
• The StorageAccount attribute applied to the same parameter as the trigger or binding attribute.
• The StorageAccount attribute applied to the function.
• The StorageAccount attribute applied to the class.
• The default storage account for the function app, which is defined in the AzureWebJobsStorage application setting.

The following table explains the properties that you can set on the options object passed to the input.table() method.

The following table explains the binding configuration properties that you set in the function.json file.

An isolated worker process class library compiled C# function runs in a process isolated from the runtime.

An in-process class library is a compiled C# function that runs in the same process as the Functions runtime.

To return a specific entity by key, use a binding parameter that derives from TableEntity.

To execute queries that return multiple entities, bind to a [TableClient] object. You can then use this object to create and execute queries against the bound table. Note that [TableClient] and related APIs belong to the Azure.Data.Tables namespace.

To return a specific entity by key, use a binding parameter that derives from TableEntity.

To execute queries that return multiple entities, bind to a CloudTable object. You can then use this object to create and execute queries against the bound table. Note that CloudTable and related APIs belong to the Microsoft.Azure.Cosmos.Table namespace.

To return a specific entity by key, use a binding parameter that derives from TableEntity. The specific TableName, PartitionKey, and RowKey are used to try and get a specific entity from the table.

To execute queries that return multiple entities, bind to an IQueryable<T> of a type that inherits from TableEntity.

When working with a single table entity, the Azure Tables input binding can bind to the following types:

When working with multiple entities from a query, the Azure Tables input binding can bind to the following types:

¹ To use these types, you need to reference Microsoft.Azure.Functions.Worker.Extensions.Tables 1.2.0 or later and the common dependencies for SDK type bindings.

To return a specific entity by key, use a plain-old CLR object (POCO). The specific TableName, PartitionKey, and RowKey are used to try and get a specific entity from the table.

When returning multiple entities as an IEnumerable<T>, you can instead use Take and Filter properties to restrict the result set.

Functions version 1.x doesn't support isolated worker process.

Get the input row data by using context.extraInputs.get().

Get the input row data by using context.bindings.<name> where <name> is the value specified in the name property of function.json.