efcore-patterns

1# Entity Framework Core Patterns
2 
3## When to Use This Skill
4 
5Use this skill when:
6- Setting up EF Core in a new project
7- Optimizing query performance
8- Managing database migrations
9- Integrating EF Core with .NET Aspire
10- Debugging change tracking issues
11- Loading multiple navigation collections efficiently (query splitting)
12 
13## Core Principles
14 
151. **NoTracking by Default** - Most queries are read-only; opt-in to tracking
162. **Never Edit Migrations Manually** - Always use CLI commands
173. **Dedicated Migration Service** - Separate migration execution from application startup
184. **ExecutionStrategy for Retries** - Handle transient database failures
195. **Explicit Updates** - When NoTracking, explicitly mark entities for update
20 
21---
22 
23## Pattern 1: NoTracking by Default
24 
25Configure your DbContext to disable change tracking by default. This improves performance for read-heavy workloads.
26 
27```csharp
28public class ApplicationDbContext : DbContext
29{
30    public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options)
31        : base(options)
32    {
33        // Disable change tracking by default for better performance on read-only queries
34        // Use .AsTracking() explicitly for queries that need to track changes
35        ChangeTracker.QueryTrackingBehavior = QueryTrackingBehavior.NoTracking;
36    }
37 
38    public DbSet<Order> Orders => Set<Order>();
39    public DbSet<Customer> Customers => Set<Customer>();
40}
41```
42 
43### When NoTracking is Active
44 
45**Read-only queries work normally:**
46…