Http 500 error : ASP.NET Core, Angular SQL Server database

The HTTP 500 error in the ASP.NET Core backend after deployment to Azure is likely due to database connectivity issues, insufficient permissions, or misconfiguration.

To Avoid above error, Add the Connection string to Azure App Service Environment Variable as shown below.

Make sure Add current Ip Address and Allow Azure Service in the Networking section of Azure Sql Server.

Below is my Program.cs :

using Microsoft.EntityFrameworkCore;
using WebApplication3.Data;
using WebApplication3.Models;
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddDbContext<ApplicationDbContext>(options =>
            options.UseSqlServer(builder.Configuration.GetConnectionString("DefaultConnection")));
builder.Services.AddControllers();
builder.Services.AddCors(options =>
{
    options.AddPolicy("AllowAngularApp",
        builder => builder.WithOrigins("http://localhost:4200")
                          .AllowAnyMethod()
                          .AllowAnyHeader());
});
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();
var app = builder.Build();
if (app.Environment.IsDevelopment())
{
    app.MapOpenApi();
}
if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
};
app.UseCors("AllowAngularApp");
app.UseHttpsRedirection();
app.MapControllers();
var summaries = new[]
{
    "Freezing", "Bracing", "Chilly", "Cool", "Mild", "Warm", "Balmy", "Hot", "Sweltering", "Scorching"
};
app.MapGet("/weatherforecast", () =>
{
    var forecast = Enumerable.Range(1, 5).Select(index =>
        new WeatherForecast
        (           DateOnly.FromDateTime(DateTime.Now.AddDays(index)),
            Random.Shared.Next(-20, 55),
            summaries[Random.Shared.Next(summaries.Length)]
        ))
        .ToArray();
    return forecast;
})
.WithName("GetWeatherForecast");
app.MapstudentEndpoints();
app.Run();
internal record WeatherForecast(DateOnly Date, int TemperatureC, string? Summary)
{
    public int TemperatureF => 32 + (int)(TemperatureC / 0.5556);
}

Add Azure Backend URL to Angular Project:

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { Observable } from 'rxjs';
@Injectable({
  providedIn: 'root',
})
export class StudentService {
  private apiUrl = 'https://<AzureWebAppName>.canadacentral-01.azurewebsites.net/api/Students';
  constructor(private http: HttpClient) {}
  getStudents(): Observable<any[]> {
    return this.http.get<any[]>(this.apiUrl);
  }
  addStudent(student: any): Observable<any> {
    return this.http.post<any>(this.apiUrl, student);
  }
  updateStudent(student: any): Observable<void> {
    return this.http.put<void>(`${this.apiUrl}/${student.id}`, student);
  }
  deleteStudent(id: number): Observable<void> {
    return this.http.delete<void>(`${this.apiUrl}/${id}`);
  }
}

After following above steps, I was successfully call the data from backend to frontend. Output: