{"id":595868,"date":"2025-09-02T12:39:28","date_gmt":"2025-09-02T11:39:28","guid":{"rendered":"https:\/\/blog.jetbrains.com\/?post_type=dotnet&p=595868"},"modified":"2025-09-02T13:45:36","modified_gmt":"2025-09-02T12:45:36","slug":"dotinsights-september-2025","status":"publish","type":"dotnet","link":"https:\/\/blog.jetbrains.com\/en\/dotnet\/2025\/09\/02\/dotinsights-september-2025","title":{"rendered":"dotInsights | September 2025"},"content":{"rendered":"\n

Did you know?<\/strong> The C# language has a GOTO statement<\/a>? It sure does. This is a case of \u201cjust because you could doesn\u2019t mean you should\u201d.<\/p>\n\n\n\n

\"dotInsights<\/figure>\n\n\n\n

Welcome to dotInsights by JetBrains! This newsletter is the home for recent .NET and software development related information.<\/p>\n\n\n\n

? Featured Content<\/h2>\n\n\n\n

This month\u2019s featured content is from Chris Woodruff!<\/strong> Chris has been at the forefront of software development since before the first .COM boom, building a career that spans enterprise web development, cloud solutions, software analytics, and developer relations. As an Architect, he applies his deep technical expertise to tackle complex challenges, with a particular focus on API design and scalable architectures. He is recognized as a Microsoft MVP specializing in .NET and Web Development. Woody\u2019s impact extends beyond his professional responsibilities; he is a dedicated mentor and educator, teaching courses that help individuals transition into tech careers. His passion for sharing knowledge has made him a sought-after speaker at international conferences, where he discusses topics such as database development, web APIs, and software architecture. He contributes to the developer community by co-hosting The Breakpoint Show<\/a> podcast and creating content that aids engineers in refining their skills.<\/em><\/p>\n\n\n\n

Entity Framework Core (EF Core)<\/strong> has emerged as the preferred Object-Relational Mapping (ORM) tool for modern .NET developers. However, effectively utilizing it requires more than just familiarity with methods like .Add()<\/code> and .SaveChanges()<\/code>. This concise newsletter summarizes the essential insights from a full-day EF Core workshop (contact Woody for details below if interested), equipping you with the knowledge necessary to build fast, secure, and scalable data access layers.<\/p>\n\n\n\n

Getting Started with EF Core<\/strong>
EF Core is a lightweight, extensible, and high-performance data access framework. It supports a clean code-first approach while allowing database-first flexibility when needed.<\/p>\n\n\n\n

Key Concepts:
\u2705 DbContext is your gateway to the database. It manages connections change tracking, and query execution.
\u2705 Use DbSet<T> to represent your entity collections.
\u2705 Code-First is ideal for domain-driven development; use Fluent API to fine-tune schema mappings.
?Pro Tip: Always register your DbContext as Scoped. Avoid Singleton lifetimes to prevent memory issues and concurrency errors.<\/p>\n\n\n\n

Modeling Relationships Like a Pro<\/strong>
EF Core handles common relationship types easily, but it\u2019s up to you to configure them correctly.<\/p>\n\n\n\n

Modeling Must-Knows:
\u2705 Define one-to-many with .HasMany().WithOne()
\u2705 Use explicit foreign keys in your model for clarity.
\u2705 Prefer eager loading (.Include()) for web APIs to avoid runtime surprises.
?Pro Tip: Don\u2019t rely on lazy loading in APIs. It hides performance issues and can cause excessive database queries.<\/p>\n\n\n\n

Querying with Power and Precision<\/strong>
LINQ is a powerful abstraction, but be intentional.<\/p>\n\n\n\n

Performance-First Query Tips:
\u2705 Use .Select() to shape the result into DTOs, avoid sending entire entities.
\u2705 Apply .AsNoTracking() for read-only queries to reduce memory use.
\u2705 Chain .Where() and .OrderBy() before projection to reduce query size.
?Pro Tip: Avoid over-fetching by skipping unnecessary .Include() chains. Smaller queries are faster queries.<\/p>\n\n\n\n

SQL Server: Tune What EF Core Generates<\/strong>
You\u2019re still writing SQL, it\u2019s just hidden behind LINQ.<\/p>\n\n\n\n

SQL Server Optimization:
\u2705 Use SSMS to inspect EF-generated SQL.
\u2705 Read execution plans to diagnose slow queries.
\u2705 Tune indexes based on frequent query filters or sorts.
\u2705 Leverage Query Store to monitor historical query behavior
?Pro Tip: Computed columns and filtered indexes can supercharge performance when used intentionally.<\/p>\n\n\n\n

Secure Your Data Layer<\/strong>
EF Core doesn’t protect you from bad design. Data security must be implemented in your access layer.<\/p>\n\n\n\n

Security Strategies:
\u2705 Use DTOs to prevent overposting.
\u2705 Filter by user role or claim inside the query, not afterward.
\u2705 Never interpolate raw SQL, always parameterize inputs.
\u2705 Store secrets securely: Use User Secrets in dev, Managed Identity in Azure.
?Pro Tip: Your DbContext is an attack surface. Secure it like you would any API.<\/p>\n\n\n\n

Testing EF Core with Confidence<\/strong>
Testing EF Core doesn\u2019t have to be painful, use the right tools.<\/p>\n\n\n\n

Approach by Test Type:
\u2705 Use In-Memory provider for fast unit tests, but be aware it behaves differently from SQL Server.
\u2705 Prefer SQLite in-memory for a closer match to production.
\u2705 Use Testcontainers or local SQL Server for full integration testing.
?Pro Tip: Seed data should be scenario-specific and reset between tests. Use Respawn or EF-based seeding for consistency.<\/p>\n\n\n\n

Scaling for the Cloud<\/strong>
Cloud-readiness means EF Core must handle concurrency, resiliency, and high throughput.<\/p>\n\n\n\n

Cloud-Ready Practices:
\u2705 Use DbContextPool for high-performance APIs.
\u2705 Configure retry logic with EnableRetryOnFailure(), and even better, learn and use Polly, which is a library for .NET designed for resilience and transient-fault handling. It enables developers to express policies such as Retry, Circuit Breaker, Timeout, Bulkhead Isolation, and Fallback in a fluent, thread-safe manner.
\u2705 Apply distributed caching at the service layer, not the EF level.
\u2705 Use sharded\/multi-tenant strategies carefully: filtered queries, schema separation, or even DB-per-tenant.
?Pro Tip: Azure SQL + EF Core is a battle-tested combo, just don\u2019t forget to tune your retry strategies and monitor connection health.<\/p>\n\n\n\n

Common Pitfalls and How to Avoid Them<\/strong>
Even experienced developers can fall into subtle traps when working with EF Core. Here are some of the most common mistakes, and how to dodge them in your projects.<\/p>\n\n\n\n

\u274c Lazy Loading in APIs
Lazy loading can cause unexpected multiple queries per request. In web APIs, it often results in the dreaded N+1 problem.
\u2705 Use Eager Loading or Projections
Explicitly load related data with .Include() or shape the query using .Select() and DTOs.<\/p>\n\n\n\n

\u274c Leaking Entities to the Client
Exposing EF entities directly in your controllers or UI tightly couples your domain to your database schema.
\u2705 Use DTOs or ViewModels
Map to dedicated types that represent what the consumer needs. Nothing more, nothing less.<\/p>\n\n\n\n

\u274c Overusing .Include() Chains
Deep includes may look convenient, but can result in massive SQL joins and redundant data loading.
\u2705 Load Only What You Need
Be intentional. Use shaped queries and projections for complex object graphs.<\/p>\n\n\n\n

\u274c Ignoring Execution Plans and SQL Output
If you\u2019re not inspecting the SQL your LINQ generates, you\u2019re flying blind.
\u2705 Use SSMS and Query Store
Always review generated SQL for critical paths. Use SQL Server tooling to optimize indexes and execution plans.<\/p>\n\n\n\n

Ready to Go Deeper?<\/strong><\/p>\n\n\n\n

? Explore Chris’s GitHub repo with all of his EF Core demos<\/a>. <\/p>\n\n\n\n

?\ufe0f Need help applying this in production or want to discuss the workshop? Book some time or have a code review with Chris<\/a>. <\/p>\n\n\n\n

? Links<\/h2>\n\n\n\n

Here\u2019s the latest from the developer community.<\/p>\n\n\n\n