Tag: ef-core

Add a rowversion concurrency token in EF Core 11: the [Timestamp] and IsRowVersion setup, the SQL EF actually emits, catching DbUpdateConcurrencyException, store-wins vs client-wins vs merge, disconnected APIs with ETags, and the five traps that silently disable the whole thing.

Store C# enums as readable strings instead of ints in EF Core 11: HasConversion, bulk configuration for every enum, the nvarchar(max) trap, the ordering gotcha, and how to migrate an existing int column.

Add Microsoft.EntityFrameworkCore.Design to the startup project that dotnet ef builds, not the project holding your DbContext, and pass -s in layered solutions.

EF Core throws PendingModelChangesWarning when your model no longer matches the last migration snapshot. Add the migration, or fix the false positive behind it.

A complete guide to deploying EF Core 11 schema changes with migration bundles: building efbundle in CI, the appsettings.json trap with named connection strings, self-contained bundles and the Alpine musl RID, migration locking since EF Core 9, rolling back with a target migration, and why per-migration transactions do not save you on MySQL.

On EF Core 11, default to complex types for value objects and drop to owned entities only when you need a separate table or a collection mapped to its own rows.

On EF Core 11, default to TPH for almost every hierarchy, reach for TPC only when you mostly query one leaf type and a benchmark proves it wins, and use TPT only when an external constraint forces you to.

This exception means you called .First() or .Single() on an empty sequence. Use FirstOrDefault/SingleOrDefault and null-check, or guard the query, or fix why the source is empty.

See the exact SQL Entity Framework Core 11 sends to your database, with parameter values, using LogTo, Microsoft.Extensions.Logging, and ToQueryString.

EF Core hit a property it does not know how to store. Map it as a complex type, convert it with HasConversion, give it a key, or ignore it with [NotMapped].