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ef-core

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Get best practices for Entity Framework Core

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Source SKILL.md: https://github.com/majiayu000/claude-skill-registry/blob/HEAD/skills/development/ef-core-beel-collab-presets/SKILL.md

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Entity Framework Core Best Practices

Your goal is to help me follow best practices when working with Entity Framework Core.

Data Context Design

  • Keep DbContext classes focused and cohesive
  • Use constructor injection for configuration options
  • Override OnModelCreating for fluent API configuration
  • Separate entity configurations using IEntityTypeConfiguration
  • Consider using DbContextFactory pattern for console apps or tests

Entity Design

  • Use meaningful primary keys (consider natural vs surrogate keys)
  • Implement proper relationships (one-to-one, one-to-many, many-to-many)
  • Use data annotations or fluent API for constraints and validations
  • Implement appropriate navigational properties
  • Consider using owned entity types for value objects

Performance

  • Use AsNoTracking() for read-only queries
  • Implement pagination for large result sets with Skip() and Take()
  • Use Include() to eager load related entities when needed
  • Consider projection (Select) to retrieve only required fields
  • Use compiled queries for frequently executed queries
  • Avoid N+1 query problems by properly including related data

Migrations

  • Create small, focused migrations
  • Name migrations descriptively
  • Verify migration SQL scripts before applying to production
  • Consider using migration bundles for deployment
  • Add data seeding through migrations when appropriate

Querying

  • Use IQueryable judiciously and understand when queries execute
  • Prefer strongly-typed LINQ queries over raw SQL
  • Use appropriate query operators (Where, OrderBy, GroupBy)
  • Consider database functions for complex operations
  • Implement specifications pattern for reusable queries

Change Tracking & Saving

  • Use appropriate change tracking strategies
  • Batch your SaveChanges() calls
  • Implement concurrency control for multi-user scenarios
  • Consider using transactions for multiple operations
  • Use appropriate DbContext lifetimes (scoped for web apps)

Security

  • Avoid SQL injection by using parameterized queries
  • Implement appropriate data access permissions
  • Be careful with raw SQL queries
  • Consider data encryption for sensitive information
  • Use migrations to manage database user permissions

Testing

  • Use in-memory database provider for unit tests
  • Create separate testing contexts with SQLite for integration tests
  • Mock DbContext and DbSet for pure unit tests
  • Test migrations in isolated environments
  • Consider snapshot testing for model changes

When reviewing my EF Core code, identify issues and suggest improvements that follow these best practices.