EF Core with Patterns

Talk by Tony Sneed and Long Le to ASP.NET Dev Group in Dallas Feb 2018.

Transcript

1. Entity Framework Core With Design Patterns Anthony Sneed with Long Le
2. About Tony • Independent Consultant @
 Pioneer Natural Resources • Coding C# since v1 • Author / Instructor:
 DevelopMentor, Wintellect • Open Source:
 URF, Trackable Entities
 ASPNET Core, EF Core • blog.TonySneed.com • Twitter: @tonysneed
3. About Le • Principle Architect @
 Pioneer Natural Resources • Currently geeking out w/ MEAN & .NET Core • Open Source:
 URF.Core, Trackable Entities • blog.longle.io • Twitter: @lelong37
4. Part 1: Intro to EF Core
5. EF Core: Not Your Father’s EF • Re-written from the ground up! • .NET Standard 2.0 • Cross-Platform, Containers, Cloud Friendly • Modern, Modular, Extensible • Lightweight, Performant
6. EF Core: What’s Hot? • Cross Platform, Container / Cloud Friendly • Batching update statements • In-memory provider (mockless testing) • Mixing client / server query evaluation • Mixing raw SQL and LINQ expressions • Customizable conventions, migrations
7. EF Core: What’s Dropped? • EDMX Models, Entity SQL (vs code-based modeling) • Mapping stored procedures to CUD operations • Many-to-Many without intermediate entity • Full support for geospatial • Built-in design tools and wizards • Table-per-type inheritance mapping (TPH supported)
8. EF Core vs EF 6 • EF 6 still supported, but considered legacy • Use EF Core for new ASP.NET Core API’s • Feature-by-feature EF 6 vs Core comparison:
 https://docs.microsoft.com/en-us/ef/efcore-and- ef6/features
9. Migrate from EF6 to Core? Don’t even think about it!
10. EF Core 2.x: What’s New? • GroupBy query translation • Lazy Loading • Scaffold context and entities separately* • System.Transactions support • Table-splitting, owned types, db scalar functions • Compiled queries, context pooling * Tony’s contrib :)
11. EF Core Power Tools • Reverse engineer • Visualize model • Customize entity classes (Handlebars templates*) * Tony’s contrib :)
13. Part 2: Design Patterns for EF Core
14. Why Patterns? • Using EF directly couples your app to EF • Newing up DbContext makes your app
 less testable
15. Repository Pattern • Repository interfaces decouple app from persistence concerns
16. Sample Repository public class ProductRepository : IProductRepository { private readonly NorthwindContext _dbContext; public ProductRepository(NorthwindContext dbContext)
 { _dbContext = dbContext; } public async Task<Product> FindAsync(int id) { return await _dbContext.Products.FindAsync(id); } }
17. Marking Changes public void Insert(Product product) { // Mark Added _dbContext.Products.Add(product); } public void Update(Product product) { // Mark Modified _dbContext.Products.Update(product); } public async Task Delete(int id) { // Mark Deleted var product = await _dbContext.Products.FindAsync(id) _dbContext.Products.Remove(product); }
18. Unit of Work Pattern • Save changes from multiple repositories • Wrapped in a single transaction
19. Persisting Changes public interface IUnitOfWork { Task<int> SaveChangesAsync(); }
20. Dependency Injection • DI container responsible for supplying instances • DI is built into ASP.NET and EF Core
21. Helpful Frameworks • URF: Generic Unit of Work and Repository https://github.com/urfnet/URF.Core
22. Helpful Frameworks • Trackable Entities: N-Tier Support for EF Core https://github.com/TrackableEntities/ TrackableEntities.Core
24. Thank You! Tony Sneed: @tonysneed
 Long Le: @lelong37 Slides:
 https://speakerdeck.com/tonysneed/ef-core-with-patterns Bits: https://github.com/tonysneed/Demo.EfCore.Patterns