Ef-Core on Ravindra Devrani

Dotnet Core Identity With .NET CLI

Tue, 10 Feb 2026 16:05:18 +0530

Aspnet core identity provides an UI to registration, login, manage users, password, external authentication (google, twitter, facebook etc). In simple words, We can say it is an authentication and authorization feature in just few lines of commands and code. It is a nice feature, if you don’t want to use other managed authentication providers like Azure Entra Id / Okta Auth0 etc.

Visual studio provides an UI way to enable identity. Which is very straightforward, but using CLI can be a little bit tricky. It is not always the case you are using visual studio (specially if you are using mac or linux). I use linux also. That is the whole reason to write this article.

LeftJoin and RightJoin in Ef Core 10

Tue, 16 Dec 2025 09:40:05 +0530

Previously there was no simple solution for left or right join. We had to use DefaultIfEmpty or GroupJoin and SelectMany.

With DefaultIfEmpty():

var customerOrders = await (
 from c in ctx.Customers
 join o in ctx.Orders on c.CustomerId equals o.CustomerId into orders
 from o in orders.DefaultIfEmpty()
 select new {
 c.CustomerId,
 c.CustomerName,
 OrderId = o == null ? 0 : o.OrderId
 }
).ToListAsync();

I have used the way described above in most of my career. It was really hard to remember that syntax and I always struggled with that.

Lazy Loading and N+1 Query Problem in Entity framework Core

Thu, 27 Nov 2025 15:34:26 +0530

💻Source code

Lazy loading

You load related entities on demand rather loading at once. This approach is usually useful when you want to load related entities on a certain condition (otherwise always use eager loading).

To enable lazy loading, you need to install this package: Microsoft.EntityFrameworkCore.Proxies

And do following changes in Program.cs

builder.Services.AddDbContext<AppDbContext>(o=>o.UseLazyLoadingProxies()
.UseSqlite("Data Source = mydb.db"));

Look at the example below:

app.MapGet("/", async (AppDbContext context) => {
 foreach (var genre in await context.Genres.ToListAsync()) 
 {
 foreach (var book in genre.Books)
 {
 Console.WriteLine($"===> genre: {genre.Name}, Book: {book.Title}, Price : {book.Author}");
 }
 }
 return Results.Ok("Ok");
});

We are not loading books with genres at once. Rather we are loading books for each genres. Let’s take a look at logs of console.

Database Firsts Approach In EF Core

Mon, 24 Feb 2025 17:49:15 +0530

I have used database first approach in the .NET Framework 4.X. But It is the first time I am trying to use Db First approach in the .NET Core (I am using .net 9). Microsoft refers it ‘Scaffolding (Reverse Engineering)’. Personally I prefer Dapper for DB First approach. May be you have an existing database and you want to use it with ENTITY FRAMEWORK, then this approach might be helpful. I am playing around it and documenting it and sharing that journey with you. Let’s see what it offers.