Blog
Mert Özen's blog posts on software development, backend, frontend, and DevOps.
What's New in EF Core 10: Named Query Filters, LeftJoin and Complex Types in JSON
Named query filters and IgnoreQueryFilters(["..."]), LeftJoin/RightJoin, ExecuteUpdateAsync with a regular lambda, complex types and ComplexCollection mapped to JSON, padded parameterized collections, vector search with SqlVector and the SQLite DateTimeOffset breaking change in EF Core 10 LTS.
What's New in EF Core 9: UseSeeding, Migration Locking and PendingModelChangesWarning
PendingModelChangesWarning catching a missing migration at Migrate time, the HasData and DateTime.Now trap, UseSeeding/UseAsyncSeeding, migration locking with __EFMigrationsLock, auto-discovered compiled models and EFOptimizeContext, and ExecuteUpdate with complex types in EF Core 9.
What's New in EF Core 8: Complex Types, Primitive Collections and SqlQuery<T>
Primitive collections and json_each, ComplexProperty for value objects, SqlQuery<T> for non-entity types, no-tracking lazy loading, JSON on SQLite and HierarchyId in EF Core 8 LTS, plus Contains moving to OPENJSON and UseCompatibilityLevel(120).
What's New in EF Core 7: ExecuteUpdate, ExecuteDelete, JSON Columns and TPC
ExecuteUpdate/ExecuteDelete, ToJson for owned types in JSON columns, TPC inheritance, IMaterializationInterceptor, FromSql and SqlQuery<int> in EF Core 7, plus moving from EF Core 6 with breaking changes like Encrypt=True and HasTrigger.
Legacy Projects: Moving from EF Core 3.1 and EF Core 5 to EF Core 6
The end of client evaluation in EF Core 3.0, FromSql split into FromSqlRaw/FromSqlInterpolated, many-to-many, filtered include and split queries in EF Core 5, how Nullable affects migrations when moving to EF Core 6, and support status.
EF Core and Architecture: Repositories, the Read Side of CQRS and Moving to Dapper
With real SQL we see how a generic repository silently moves the WHERE into memory, and discuss DbContext already being a unit of work. We finish the core block with an aggregate-specific repository, projections on the CQRS read side and Dapper sharing the same connection and transaction.
Testing with EF Core: SQLite In-Memory and InMemory Provider Pitfalls
With real test output we see how the InMemory provider silently lets unique indexes, foreign keys and raw SQL slip through, and build realistic tests with SQLite in-memory. We cover the false green of asserting on the same context and the debate about abstracting DbContext, using the EF documentation's guidance.
EF Core Interceptors and Events: Audit Fields and Slow Query Logging
We fill CreatedAt and UpdatedAt automatically with a SaveChangesInterceptor, log queries over a threshold with a DbCommandInterceptor, and watch the change tracker live through SavingChanges and StateChanged events. We also see why nothing runs when you forget the async override.
Owned Types and Value Converters in EF Core: Addresses, Enums and Strongly Typed Ids
We tie identity-less values to their owner with OwnsOne and OwnsMany, store enums as text and wrap Ids in their own types. With real output we see a change lost for lack of a value comparer and an OwnsMany pitfall specific to SQLite.
Inheritance Mapping in EF Core: TPH, TPT and When to Choose Which
How does EF Core turn a class hierarchy into tables? We compare TPH with its discriminator column and TPT with a table per type using real SQL output, and look at silent pitfalls like a subclass missing from the model.
Global Query Filters in EF Core: Soft Delete, Multi-Tenancy and IgnoreQueryFilters
We build soft delete and multi-tenancy with HasQueryFilter, turn Remove into an UPDATE, switch filters off with IgnoreQueryFilters, and examine relationship pitfalls such as rows that vanish through an INNER JOIN on required navigations, with real SQL.
EF Core Performance Basics: N+1, Projection, AsNoTracking and Compiled Queries
We catch N+1 queries by counting commands, switch to DTO projections, measure the effect of tracking, indexes, split queries and compiled queries on SQLite, and monitor queries with TagWith and LogTo.