Get Distinct Records from a DataTable in C# Using LINQ
Add comment
To get distinct records from a DataTable in C#, use LINQ to DataSet. When rows must be identical in every column, call Distinct(DataRowComp...
Read tutorial
Topic
ASP.NET Core
Build ASP.NET Core applications with Web API, dependency injection, EF Core and deployment guides. Check each tutorial for its framework version.
OpenAI Codex CLI Tutorial for C#: Build a .NET 10 API
This OpenAI Codex CLI tutorial shows OpenAI Codex for C# developers in practice: how an AI coding agent can inspect a repository, implement ...
Read tutorial
Claude Code vs GitHub Copilot for ASP.NET Core Developers
If you write C# for a living, the question is no longer whether to try an AI coding tool. The real decision is which workflow fits the way y...
Read tutorial
Read CSV File in ASP.NET Core & Web Forms (C#, VB.NET)
To read a CSV file in ASP.NET, accept the upload, parse it with a real CSV parser, validate each record, and show the rows in a tab...
Read tutorial
Secure JWT Authentication with HttpOnly Refresh Tokens in ASP.NET Core Web API
The short answer: Don't store JSON Web Tokens (JWTs) in localStorage , because any JavaScript running on your page can read them. In AS...
Read tutorial
Upgrade to .NET 10 from .NET 8/9: Common Build Errors, Breaking Changes, and How to Fix Them
The short answer: To upgrade to .NET 10 from .NET 8 or 9, install the .NET 10 SDK, change your target framework moniker (TFM) to net...
Read tutorial
Migrate Roles to Policy-Based Authorization in ASP.NET Core
Many ASP.NET Core projects start the same way. Someone adds [Authorize(Roles = "Admin")] to a controller, it works, and the team ...
Read tutorial
ASP.NET Core Dependency Injection Interview Questions (30)
Introduction If you're preparing for a .NET developer interview, dependency injection questions will come up — not as a formality,...
Read tutorial
Razor Pages ASP.NET Core FAQ: 27 Beginner Questions
Razor Pages in ASP.NET Core: What This FAQ Covers Razor Pages is a page-based way to build server-rendered web apps in ASP.NET Core. E...
Read tutorial
Migrate ASP.NET Identity to ASP.NET Core Identity Safely
Short answer: to migrate ASP.NET Identity to ASP.NET Core Identity, copy your legacy AspNetUsers rows (including PasswordHash ) into the n...
Read tutorial
Migrate ASP.NET Core from IIS to Azure App Service (.NET 10)
If you need to migrate an ASP.NET Core website from IIS to Azure App Service, the move is easy once you know the order of the steps. This be...
Read tutorial
C# List to CSV: CsvHelper vs. StreamWriter
Data portability is a requirement for almost every business application. Whether you are building an admin dashboard, a reporting tool, or a...
Read tutorial
Angular 22 CRUD Example with ASP.NET Core Web API and .NET 10
In this article, we will build a CRUD (Create, Read, Update, Delete) application with Angular, an ASP.NET Core Web API and a SQL Server data...
Read tutorial
Structured Logging Architecture with Serilog in ASP.NET Core
Most ASP.NET Core projects start their logging story the same way: someone adds Serilog, wires up a console sink and a file sink, and c...
Read tutorial
How to Secure an ASP.NET Core Deployment on Linux (Nginx & Systemd)
If you want to secure a .NET Core deployment on Linux, the short answer is this: never expose Kestrel directly to the internet, put a r...
Read tutorial
Secure ASP.NET Core Web API JWT Authentication
If you've already wired up JWT bearer authentication in an ASP.NET Core Web API, you've solved maybe a third of the actual security ...
Read tutorial
EF Core Query Performance: AsNoTracking, Loading & N+1
Most EF Core performance problems don't announce themselves. You write clean LINQ, the app works fine locally against a small seed datab...
Read tutorial
N+1 Query Problem in ASP.NET Core & EF Core: How to Fix It
If your ASP.NET Core API feels slow under real traffic even though every individual query looks fine in isolation, there's a good chance...
Read tutorial
REST API Interview Questions for ASP.NET Core Developers
If you're prepping for a .NET backend interview, chances are the panel will spend at least half the conversation on REST API design and ...
Read tutorial
Creating a CQRS Architecture in .NET Core 8
In modern software development, scalability and maintainability are crucial. The CQRS architecture in .NET Core 8 offers an effective solut...
Read tutorial