Entity Framework: Advanced Scenarios

This section delves into more complex and specialized usage patterns for Entity Framework, going beyond the basic CRUD operations and querying.

1. Performance Optimization

Achieving optimal performance with Entity Framework is crucial for scalable applications. This involves understanding how EF translates LINQ queries into SQL and how to influence that translation.

1.1. Eager Loading vs. Lazy Loading

Understand the trade-offs between loading related data immediately (eager loading) or only when it's accessed (lazy loading). Effective use of Include() and ThenInclude() is key for eager loading.

1.2. Query Batching

Entity Framework Core supports query batching, which can significantly reduce the number of round trips to the database for multiple queries executed in sequence.

1.3. Compiled Queries

For highly repetitive queries, compiling them can offer performance benefits by pre-compiling the LINQ expression tree into a reusable query plan.

1.4. Connection Resiliency and Command Interception

Implement strategies to handle transient database connection errors and gain insights into the SQL generated by Entity Framework.

2. Handling Complex Data Models

Entity Framework excels at mapping object-oriented models to relational databases. This section covers scenarios with more intricate data structures.

2.1. Table-Per-Hierarchy (TPH), Table-Per-Type (TPT), and Table-Per-Concrete-Type (TPC)

Explore different strategies for mapping inheritance hierarchies to database tables, each with its own performance and design implications.

2.2. Owned Entities

Use owned entities to model complex types that don't have their own identity and are part of another entity, effectively flattening them into the parent entity's table.

2.3. Value Objects

Represent entities that are defined by their attributes rather than a unique identifier. Value objects are immutable and are typically persisted as part of the owning entity.

3. Advanced Querying Techniques

Beyond standard LINQ, EF provides powerful ways to interact with your data.

3.1. Raw SQL Queries

When LINQ falls short, or for performance-critical scenarios, you can execute raw SQL queries directly against the database. This is also useful for leveraging database-specific features.

var users = await _context.Users
                .FromSqlRaw("SELECT * FROM [Users]")
                .ToListAsync();

3.2. Stored Procedures

EF Core allows you to call stored procedures and map their results to your entity types.

3.3. Interceptors

Interceptors provide a mechanism to hook into EF Core's operational pipeline, allowing you to observe or modify operations like command execution, saving changes, or loading entities.

4. Concurrency Management

Handling concurrent updates to the same data is a common challenge. Entity Framework offers several mechanisms to address this.

4.1. Optimistic Concurrency

Use row versioning or timestamp columns to detect and handle concurrent updates gracefully, preventing data loss.

4.2. Pessimistic Concurrency

For scenarios where conflicts are frequent or data integrity is paramount, consider database-level locking mechanisms.

5. Customizing Entity Framework Behavior

Tailor Entity Framework to your specific needs with various customization options.

5.1. Custom Conventions

Define your own conventions for naming, mapping, and behavior to streamline your model configuration.

5.2. Custom Value Converters

Handle the conversion of .NET types to database types that are not directly supported by EF Core.

5.3. Global Query Filters

Apply filters to all queries of a specific entity type, such as soft delete flags or tenant IDs.