Swevo.EFCore.RowVersion

Compile-time optimistic concurrency for EF Core. Stamp [Optimistic] on any partial entity class and the source generator wires up a RowVersion byte array property and the IOptimisticEntity interface. Two ready-made retry extensions handle concurrent-write conflicts without any Polly dependency.

Quick-start

dotnet add package Swevo.EFCore.RowVersion

1 — Mark your entities

using EFCore.RowVersion;

[Optimistic]
public partial class Order
{
    public int Id { get; set; }
    public string Description { get; set; } = "";
    // byte[] RowVersion { get; set; } is generated automatically
}

The class must be partial. Non-partial classes produce diagnostic RVRS001.

2 — Configure DbContext

public class AppDbContext(DbContextOptions<AppDbContext> options) : DbContext(options)
{
    public DbSet<Order> Orders => Set<Order>();

    protected override void OnModelCreating(ModelBuilder modelBuilder)
        => modelBuilder.AddOptimisticConcurrencyConfiguration();
}

3 — Save with retry

// Client wins — re-applies your changes over the updated DB values
await db.SaveChangesClientWinsAsync(maxRetries: 3);

// Database wins — discards your in-memory changes, accepts the DB values
await db.SaveChangesDatabaseWinsAsync(maxRetries: 3);

SQL Server setup

On SQL Server the generated [Timestamp] attribute on RowVersion is recognised by EF Core convention and automatically configures the property as a database-managed rowversion column. No additional code is needed.

// For SQL Server, also tell EF Core to use the database-managed rowversion:
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.AddOptimisticConcurrencyConfiguration();
    // Optional – [Timestamp] convention already does this for SQL Server:
    // modelBuilder.Entity<Order>().Property(o => o.RowVersion).IsRowVersion();
}

Non-SQL-Server setup

For SQLite, PostgreSQL, and other providers, override ValueGeneratedNever() and update the version manually on each save (e.g. using an interceptor):

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.AddOptimisticConcurrencyConfiguration();
    modelBuilder.Entity<Order>().Property(o => o.RowVersion).ValueGeneratedNever();
}

protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    => optionsBuilder.AddInterceptors(new VersionIncrementInterceptor());

// Interceptor that stamps a new Guid on every save
sealed class VersionIncrementInterceptor : SaveChangesInterceptor
{
    public override InterceptionResult<int> SavingChanges(DbContextEventData e, InterceptionResult<int> r)
    {
        foreach (var entry in e.Context!.ChangeTracker.Entries<IOptimisticEntity>()
            .Where(x => x.State is EntityState.Added or EntityState.Modified))
            entry.Entity.RowVersion = Guid.NewGuid().ToByteArray();
        return base.SavingChanges(e, r);
    }
}

How it works

Piece	What it does
[Optimistic]	Marks the entity for code generation
Source generator	Emits [Timestamp] byte[] RowVersion + IOptimisticEntity implementation
AddOptimisticConcurrencyConfiguration	Calls IsConcurrencyToken() for all IOptimisticEntity entities in OnModelCreating
SaveChangesClientWinsAsync	Retries on DbUpdateConcurrencyException; refreshes original values from DB, re-applies client values
SaveChangesDatabaseWinsAsync	Retries on DbUpdateConcurrencyException; reloads the entity, discards client changes

Stacking with other Swevo packages

[Optimistic]  // → RowVersion + optimistic concurrency retry
[Auditable]   // → CreatedAt, UpdatedAt
[SoftDelete]  // → IsDeleted + global query filter
[Tenant]      // → TenantId + per-tenant query filter
public partial class Order
{
    public OrderId Id { get; set; }
}

Requirements

• .NET 8+
• EF Core 8+

Also by the same author

🌐 Full suite overview: swevo.github.io

Package	Description
AutoLog.Generator	Compile-time high-performance logging — [Log(Level, Message)] generates LoggerMessage.Define. AOT-safe.
AutoHttpClient.Generator	Compile-time typed HTTP client — [HttpClient] on an interface generates a strongly-typed client. AOT-safe Refit alternative.
AutoDispatch.Generator	Compile-time CQRS dispatcher — [Handler] generates a strongly-typed IDispatcher. No MediatR, no reflection.
AutoWire	Compile-time DI auto-registration — [Scoped]/[Singleton]/[Transient] generates IServiceCollection registration code.
AutoMap.Generator	Compile-time object mapping with generated extension methods. AOT-safe AutoMapper alternative.

Related Packages

Package	Downloads	Description
Swevo.EFCore.Outbox		Transactional outbox pattern for EF Core + AutoBus
Swevo.EFCore.StronglyTyped		Compile-time strongly-typed ID generation for
Swevo.EFCore.SoftDelete		Compile-time soft-delete generation for EF Core entities using Roslyn source generators
Swevo.EFCore.Seeding		Fluent, idempotent, dependency-ordered seed data for EF Core
Swevo.EFCore.Pagination		Offset and cursor-based pagination for EF Core
Swevo.EFCore.JsonColumn		Compile-time JSON column configuration for EF Core 8+ — [JsonColumn] on owned navigation properties generates ConfigureJsonColumns(ModelBuilder) with OwnsOne(
Swevo.EFCore.BulkOperations		Free, MIT-licensed bulk insert/update/delete for EF Core
Swevo.EFCore.MultiTenant		Compile-time multi-tenancy for EF Core

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License

MIT