Blog
Mert Özen's blog posts on software development, backend, frontend, and DevOps.
Seeding in EF Core: Model Seeding with HasData and Application-Side Seeding
Two ways to add initial data in EF Core: model seeding with HasData and the InsertData/UpdateData/DeleteData it generates, the key and navigation rules, the dynamic value trap; then a rerunnable application-side seeder and a pointer to EF Core 9's UseSeeding.
EF Core Migrations: migrations add, database update, Scripts and Bundles
We run EF Core migrations end to end: migrations add/remove, database update and reverting, the anatomy of a migration file, SQL scripts and --idempotent, EF Core 6 migration bundles, and the risks of calling Migrate() at startup.
Relationships in EF Core, Part 2: One-to-One, Many-to-Many and UsingEntity
We build one-to-one with Author and AuthorProfile and many-to-many with Book and Tag: the unique foreign key index, the dependent-side error and HasForeignKey<T>, skip navigations and the BookTag table created by convention, naming the join table with UsingEntity and a join entity with a TaggedAt payload.
Relationships in EF Core, Part 1: One-to-Many, Foreign Keys and Cascade Delete
We build a one-to-many relationship with Author and Book: principal, dependent and foreign key, how the convention finds the relationship, HasOne/WithMany in the Fluent API, adding graphs and fixup, required versus optional relationships, and real SQLite output for Cascade, ClientSetNull and Restrict with loaded and unloaded dependents.
Data Annotations or Fluent API in EF Core? OnModelCreating and IEntityTypeConfiguration
We put the two ways of overriding conventions side by side: data annotations and the Fluent API in OnModelCreating. We split configuration with IEntityTypeConfiguration and ApplyConfigurationsFromAssembly, test unique indexes, check constraints and default values against real SQLite errors, and see the precedence order and the bool default trap.
Model and Conventions in EF Core: Keys, Nullability, Column Types and Shadow Properties
We read how EF Core builds its model from real schema output: the key convention, NOT NULL and NULL columns with NRT, SQLite and SQL Server column types, the decimal warning, temporary keys and Guid generation, where table names come from, and the shadow foreign key EF Core adds on its own.
Your First EF Core App: DbContext, DbSet, SQLite and the Generated SQL
We build the first EF Core app from an empty console project: the SQLite and Design packages, dotnet-ef as a local tool, DbContext and DbSet, OnConfiguring, EnsureCreated, the first insert and query, real SQL via LogTo and ToQueryString, and the SQL differences between EF Core 6 and 10.
What Is Entity Framework Core? The ORM Idea and EF Core's Architecture
Starting from plain ADO.NET code we see why ORMs exist: EF Core's DbContext, model, provider and change tracker, the different SQL SQLite and SQL Server generate from the same LINQ, EF6 versus EF Core, a Dapper comparison and how the series is organized.
What's New in .NET 10: AddValidation, OpenAPI 3.1 and Server-Sent Events in ASP.NET Core
.NET 10 LTS brings AddValidation to minimal APIs, OpenAPI 3.1 and YAML, TypedResults.ServerSentEvents, System.Text.Json-based JSON Patch, dotnet run app.cs, C# 14 and breaking changes such as cookie auth 401/403.
What's New in .NET 9: Built-in OpenAPI, Scalar and HybridCache in ASP.NET Core
.NET 9 drops Swashbuckle from the template: AddOpenApi/MapOpenApi, transformers, Scalar and Swagger UI, stampede-safe HybridCache, TypedResults.InternalServerError, StatusCodeSelector, C# 13 and 24-month STS support.
What's New in ASP.NET Core with .NET 8: Keyed DI, IExceptionHandler, Identity API and Native AOT
Keyed DI, IExceptionHandler, MapIdentityApi, ShortCircuit, TimeProvider, Native AOT and the minimal API template in .NET 8, compared with .NET 6, plus C# 12, migration notes and the November 10, 2026 end of support.
What's New in ASP.NET Core with .NET 7: MapGroup, TypedResults, Rate Limiting and Output Caching
MapGroup, TypedResults and Results<T1,T2>, endpoint filters, AddProblemDetails, rate limiting and output caching in .NET 7, compared with .NET 6, plus C# 11 required members, raw string literals and migration notes.