Build A Daily Sales Report Email Job Using Twilio SendGrid and .Net Azure Functions

June 11, 2024
Written by
Eman Hassan
Contributor
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Build A Daily Sales Report Email Job Using Twilio SendGrid, Azure SQL and .Net Azure Functions

Introduction

Reporting and notifications are crucial across industries for tracking progress, sales, and performance. One common example is a sales summary report, which consolidates the total amounts and number of items sold over a specific period. In this tutorial, you will learn how to build a daily sales report summary from an Azure SQL database table and send this summary via email.

Prerequisites

In order to be successful in this tutorial, you will need the following:

Building the app

You will start by creating the application in Visual Studio. Then you will include your database connection string in the application, so that the application can track the daily sales saved in the SQL database.

Visual Studio function app setup

Open Visual Studio. Click on Create a new project, then search for Azure Function. Click Azure Functions and click Next.

Create Azure function project

Name your project SalesReportJob and click Next. Then select the .Net runtime as .Net 8 and the function type as Timer trigger. You also need to set the schedule for when the job is going to run with the format of: {second} {minute} {hour} {day} {month} {day of week}. Set it as 0 0 * * * *, which corresponds to daily at 12 AM. Then click Create.

Additional function information

Retrieve your database’s connection string from the Azure portal by following the guidelines here . Then get back to Visual Studio, and add the connection string to local.settings.json file as shown below.

Add DB connection string

SendGrid API key

Before you can start sending emails, there are a few more mandatory steps you’ll need to complete.

Once you’ve completed the above steps, you’ll need to create a new API Key . Keep this key somewhere safe as you will need it in the subsequent steps.

Go to the file local.settings.json and add the API key as shown below

Add SendGrid connection string

Create SQL sales tables

Next, you need to open SQL Server Management Studio and connect to your Azure SQL database following the guidelines here. Make sure to allow public access in the SQL server on Azure portal by clicking on Security > Networking, then enable the option to allow public access. Then, right click the database and click on New Query. Add the following script to create two tables, one called Sales and the other called DailyReports, as shown below. Click Execute to run the queries.

create table Sales (
id int primary key identity not null,
amount decimal(10,2) not null,
saleDate datetime not null
)
Go
create table DailyReports (
reportDate datetime not null,
totalSales decimal(10,2) not null
)

Then, add some sample data to the sales table for the previous day to be able to test the job when the processing is done. Paste the following into a new query, and click Execute to run the queries.

INSERT [dbo].[Sales] ([Amount], [SaleDate]) VALUES (CAST(100.00 AS Decimal(10, 2)), DATEADD(DAY, -1, GETDATE()))
GO
INSERT [dbo].[Sales] ([Amount], [SaleDate]) VALUES (CAST(100.50 AS Decimal(10, 2)), DATEADD(DAY, -1, GETDATE()))

Add necessary packages to Visual Studio

In order to be able to get and save data from/to your SQL server, you need to install a Nuget packet called “SQL Client." Click on Tools -> Nuget Package Manager -> Manage Nuget Packages For Solution.

Visual Studio showing Tools menu

Then browse for the SQL Client package and install it to the project as shown below.

Visual Studio Nuget package manager showing selection of SQL Client package

You need to also install SendGrid’s package as shown below.

Visual Studio Nuget package manager showing selection of SendGrid

Function Implementation

Rename the file Function1.cs to Total.cs. Replace the file’s content with the following code. This code adds the queries to select the total amount from the Sales table on yesterday’s date, then connects to the database and saves these amounts to the DailyReports table. It is configured for local testing, so if you are in DEBUG mode it will run the job immediately without having to wait until 12 am to run.

using System;
using System.Data.SqlClient;
using Microsoft.AspNetCore.Mvc;
using System.Net.Mail;
using Microsoft.Azure.Functions.Worker;
using Microsoft.Extensions.Logging;
using static System.Runtime.InteropServices.JavaScript.JSType;
using SendGrid;
using SendGrid.Helpers.Mail;

namespace SalesReportJob
{
    public class Total
    {
        private readonly ILogger _logger;

        public Total(ILoggerFactory loggerFactory)
        {
            _logger = loggerFactory.CreateLogger<Total>();
        }

        [Function("Total")]
        public async Task Run([TimerTrigger("* 0 0 * * *"
#if DEBUG
            , RunOnStartup=true
#endif
            )]TimerInfo myTimer)
        {
            _logger.LogInformation($"C# Timer trigger function executed at: {DateTime.Now}");
            
            if (myTimer.ScheduleStatus is not null)
            {
                _logger.LogInformation($"Next timer schedule at: {myTimer.ScheduleStatus.Next}");
                // Get connection string of the sales SQL database
                var connectionString = Environment.GetEnvironmentVariable("DBCONNECTION_STRING");
                var yesterday = DateTime.UtcNow.Date.AddDays(-1); // For the previous day's sales

                // SQL Queries

                // Get total sales of the previous day
                string queryTotalSales = @"
            SELECT SUM(Amount) AS TotalSales
            FROM Sales
            WHERE SaleDate >= @StartDate AND SaleDate < @EndDate";

                string insertReport = @"
            INSERT INTO DailyReports (ReportDate, TotalSales)
            VALUES (@ReportDate, @TotalSales)";

                try
                {
                    // Initiate the database connection
                    await using (var connection = new SqlConnection(connectionString))
                    {
                        await connection.OpenAsync();

                        // Calculate total sales for the previous day
                        await using (var cmdTotalSales = new SqlCommand(queryTotalSales, connection))
                        {
                            cmdTotalSales.Parameters.AddWithValue("@StartDate", yesterday);
                            cmdTotalSales.Parameters.AddWithValue("@EndDate", yesterday.AddDays(1));

                            var result = await cmdTotalSales.ExecuteScalarAsync();
                            decimal totalSales = result != null && result != DBNull.Value ? (decimal)result : 0;

                            // Insert the total into the DailyReports table
                            await using (var cmdInsertReport = new SqlCommand(insertReport, connection))
                            {
                                cmdInsertReport.Parameters.AddWithValue("@ReportDate", yesterday);
                                cmdInsertReport.Parameters.AddWithValue("@TotalSales", totalSales);

                                await cmdInsertReport.ExecuteNonQueryAsync();
                            }
                            //send notification email
                            await sendEmail(totalSales, yesterday);

                        }
                    }
                    _logger.LogInformation("Total saved successfully!");

                }
                catch (Exception ex)
                {
                    _logger.LogError(ex.Message);
                }
            }
        }

        public async Task sendEmail (decimal total, DateTime date)
        {
           //TODO
        }
    }
}

After the database query saves successfully an email needs to be configured to send that day’s total amount of sales. Replace the content of the sendEmail function with the following code:

try
 {
     string toEmail = "add_your_email";
     string subject = "Daily sales report";
     string template = "<h1>Sales Report for: {0:yyyy-MM-dd}</h1><p><b>Total:</b> {1:C}</p>";
     string message = string.Format(template, date, total);

     var apiKey = Environment.GetEnvironmentVariable("SENDGRID_API_KEY");
     var client = new SendGridClient(apiKey);
     var from = new EmailAddress("add_verified_from_email", "Sales Report");
     var to = new EmailAddress(toEmail);
     var msg = MailHelper.CreateSingleEmail(from, to, subject, message, message);
     await client.SendEmailAsync(msg);
 } catch (Exception ex)
 {
     _logger.LogError(ex.Message);
 }

You will need to add your to email to the variable toEmail by replacing add_your_email,and add the verified from email to the variable from by replacing add_verified_from_email

Testing the application

Before running the application locally, you need to go to local.settings.json and replace the value of AzureWebJobsStorage with : "UseDevelopmentStorage=true". Then add another item AzureWebJobsDashboard with the value: “UseDevelopmentStorage=true”

local settings

You can now run the job by clicking on the project’s name in the toolbar

Run the app

Then after running successfully it will show a log as shown below.

App run output

You can now validate that it ran successfully by checking your email and see the total: 200.5 from the records you added in the SQL database.

Please note that when you inserted the sample data into the Sales table in the SQL database, you set the date to yesterday relative to the time you executed the insert command. Therefore, if you inserted the data and then ran the application two days later, the total will be 0 because the application only queries data from the previous day. To ensure accurate results when running the application, always add test data with the date set to yesterday’s date.

Publish the function to the Azure portal

In order to publish the function to start running daily on Azure, you need to login to the Azure portal . Search for “function app” then click on Function App.

 

Go to function app on Azure

It will take you to the Azure functions window. Click Create to create a new function app.

You can then choose the hosting plan as a Consumption plan. This allows you to pay only when the function executes. Azure gives you the first 1 million executions for free according to the guidelines mentioned here .

Hosting plan

Then add the basic settings as shown below:

Setting function app details

The tabs at the top show other aspects of your function app, but you don't need to change any of the default values. Keep clicking Next until you reach the tab: Review + Create. Click Create.

The create function app page in Azure

It will take a few moments to create the resources for you. When it is done, Azure will notify you that the resource has been created successfully. Click on Go to the resource on the notification popup.

In order to be able to publish your code, you need to go to Settings -> Configuration -> General Settings and set SCM Auth Publishing Credential to ON. Click Save. Your app may need to restart to complete this process.

Turn on basic auth for publishing

In the overview tap click on Get publish profile, and download the file. This is the file that you will attach to Visual Studio to be able to access the function app and publish your local job to Azure.

Go back to Visual Studio. Right click on the project name and click Publish.

configure publish in visual studio

Click on Import Profile and attach the publish profile that you downloaded from the Azure portal. Then click Finish.

Import publish profile

You can now click on Publish on the main publish window. It will show the following output when the publish is complete.

publish output in visual studio
Your published Azure function is going to run daily. Whenever you don’t need it anymore, make sure to disable the function on Azure.

Add connection strings and API Key to Azure

Since the file local.settings.json is only for local settings, you need to also add the SQL database’s connection string and SendGrid’s API key to Azure.

You can do this by clicking on the function app. Then go to Settings -> Environment variables and add these keys: DBCONNECTION_STRING and SENDGRID_API_KEY with the same name and value as you configured in your local file.

Security and maintainability considerations

A better way to secure your API keys and database connection strings is through Azure key vault instead of using environment variables directly. This will make this sensitive data more secure.

Another thing to keep in mind is that it is recommended to separate the SQL queries in stored procedures or use Object Relational Mapper (ORM) like Entity framework to query from and to the database, this is necessary to avoid threats like SQL injection .

To make sure your Azure Function is running properly, make sure you configure unit and integration testing . This is necessary especially when you have multiple Azure Functions running for different use cases.

Wrapping Up

At the conclusion of this tutorial, you will have acquired the skill sets to: set up and utilize Twilio SendGrid APIs, and create, configure and run an Azure function using C#. You can find the code project on github here .

Eman Hassan, a dedicated software engineer, prioritizes innovation, cutting-edge technologies, leadership, and mentorship. She finds joy in both learning and sharing expertise with the community. Explore more on her Medium profile: https://emhassan.medium.com.