How to create API wrapper for SQL stored procedure on Azure

If I already have an Azure web app, would not it be much less expensive to add the rest api to the existing app?

Having a consumption-based function app is less expensive than using Azure Web app.

As @Dan Guzmann suggested to use Azure Function.

I have used Azure function to get the stored procedure. It worked for me.

#My Stored Procedure

I have used HTTP Trigger in azure function.

#My code:

using System;
using System.IO;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;
using System.Data;
using Microsoft.Data.SqlClient;

namespace FunctionApp6
{
    public static class Function1
    {
        [FunctionName("Function1")]
        public static async Task<IActionResult> Run(
            [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)] HttpRequest req,
            ILogger log)
        {
            log.LogInformation("C# HTTP trigger function processed a request.");

            string code = req.Query["code"];
            if (string.IsNullOrEmpty(code))
            {
                return new BadRequestObjectResult("Please provide a valid code parameter.");
            }

            string connectionString = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                using (SqlCommand command = new SqlCommand("PGET_JSON", connection))
                {
                    command.CommandType = CommandType.StoredProcedure;
                    command.Parameters.AddWithValue("@code", code);

                    using (SqlDataAdapter adapter = new SqlDataAdapter (command))
                    {
                        DataTable dataTable = new DataTable();
                        adapter.Fill(dataTable);

                        if (dataTable.Rows.Count>0)
                        {
                            
                            string result = JsonConvert.SerializeObject(dataTable);

                            return new OkObjectResult(result);
                        }
                        else
                        {
                            return new NotFoundObjectResult("No data found");
                        }
                    }
                }
            }
        }
    }
}

OUTPUT:

[{"Id":123,"Name":"Vivek"}]

#Local:

#AZURE: