Ef-Core

# 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.