Top 25 Entity Framework Interview Questions and Answers

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Entity Framework (EF) is an open-source object-relational mapper (ORM) for .NET. Microsoft introduced it in 2008 to make data access simpler for developers. With EF, you can use C# code to work with databases instead of writing long SQL queries. It was first included in .NET Framework 3.5 and has evolved over time. The main goal is to make database tasks faster and easier. Since EF is widely used in modern .NET projects, it often comes up in technical interviews. In this blog, you will find 25 key Entity Framework interview questions and answers to help you prepare.

Fun Fact – Entity Framework was first launched on August 11, 2008, and its latest version, Entity Framework Core 9.0.4, was released on April 8, 2025. This shows nearly 17 years of continuous evolution and community support.

Basic Level Entity Framework Interview Questions

Here are some common Entity Framework interview questions and answers asked in beginner-level .NET interviews.

1. What is Entity Framework? Why is it used in .NET applications?

Entity Framework Core is an open-source ORM from Microsoft. It lets you work with databases using C#. You don’t need to write raw SQL for most tasks. It supports cross-platform development and is widely used in modern .NET apps.

2. What are the key differences between Code First and Database First in EF Core?

EF Core supports Code First and limited Database First workflows. Code First starts with C# models and creates the database. Reverse engineering (Scaffold-DbContext) is used to work with an existing database.

3. How does EF Core handle relationships between entities?

You define relationships using navigation properties and the Fluent API. EF Core supports one-to-one, one-to-many, and many-to-many setups.

4. What is lazy loading in Entity Framework?

Lazy loading delays loading related data until it’s accessed. You must enable it using proxies or explicit configuration.

5. What is the role of DbContext in EF Core?

DbContext is the main class that manages database connections and tracks changes to entities.

6. What is the purpose of migrations in EF Core?

Migrations let you track and apply changes to your database schema as your models evolve.

Note – Interview questions for Entity Framework often include topics like code-first vs. database-first approaches, LINQ queries, migrations, lazy loading, and performance tuning basics.

Intermediate Level Entity Framework Interview Questions

These interview questions for Entity Framework are suitable for developers with some hands-on experience using EF in projects.

7. What is change tracking in Entity Framework, and how does it work?

EF Core automatically tracks changes to entity objects. When you call SaveChanges(), it figures out which records to insert, update, or delete. You can also use AsNoTracking() to turn it off for read-only queries.

8. How does Entity Framework handle concurrency conflicts?

EF Core supports optimistic concurrency. If two users modify the same data, EF checks for conflicts using concurrency tokens like a timestamp or row version. If a conflict occurs, it throws a DbUpdateConcurrencyException.

9. What are navigation properties, and how are they used?

Navigation properties allow you to access related entities directly from your model. For example, a Post entity might include a Blog navigation property. These help EF Core build relationships and joins automatically.

10. What is the difference between eager loading and explicit loading?

Eager loading loads related data using .Include(). Explicit loading lets you load it later with context.Entry(entity).Reference(…).Load(). Eager loading is simpler; explicit gives you more control.

11. How can you update or delete records using Entity Framework?

First, fetch the entity. Update its properties or call context.Remove(entity) to delete. Then call SaveChanges() to commit changes to the database.

12. What is a migration in EF, and how do you apply it?

A migration represents changes in your model. Use Add-Migration to generate it, and Update-Database to apply it to your database. In real-world apps, migrations are often applied through CLI (dotnet ef) or included in deployment pipelines.

Advanced Level Entity Framework Interview Questions

Let’s go through some advanced interview questions for Entity Framework that test deep technical knowledge.

13. How can you improve performance when querying large datasets in Entity Framework?

Use .AsNoTracking() for read-only queries. Load only the data you need using projections like .Select(). Avoid loading large related entities unless required. You can also use compiled queries for repeated operations.

14. What are compiled queries, and when would you use them in EF?

Compiled queries let you pre-process a LINQ query and reuse it. This reduces overhead when the same query runs many times. It’s useful in high-traffic APIs or loops with heavy database access.

15. How does EF Core deal with disconnected entities in a web application?

In stateless apps like APIs, EF doesn’t track the entity after sending it to the client. To update it, you reattach the object using context.Update() or context.Attach() and call SaveChanges().

16. What are interceptors in Entity Framework, and how are they used?

Interceptors let you tap into EF Core’s pipeline. You can log queries, modify commands, or track database events. They’re added via AddInterceptors() in the DbContextOptionsBuilder.

17. How do you handle raw SQL queries in Entity Framework without compromising security?

Use FromSqlInterpolated() or parameterized queries with FromSqlRaw() to safely include user input. Never build SQL strings by hand with untrusted values.

Also Read - Top 100 SQL Query Interview Questions and Answers

Entity Framework Core Interview Questions (Latest Version 9.0.4)

You might also face EF Core interview questions focused on new features, performance, and cross-platform capabilities in version 9.0.4.

18. What are the major differences between Entity Framework and EF Core?

EF Core is cross-platform, lightweight, and faster than EF6. It supports modern features like batching, compiled queries, global filters, and is still actively developed. EF6 is Windows-only and no longer updated.

19. How does EF Core support shadow properties, and what are they used for?

Shadow properties exist in the EF model but not in your C# class. They’re useful for audit data like CreatedAt or UpdatedBy without cluttering your entity code. EF tracks and stores them in the database.

20. What is the use of value converters in EF Core?

Value converters allow you to store data in a different format. For example, you can store an enum as a string or a complex object as JSON. This keeps the database simple and readable.

21. How does EF Core handle global query filters?

Global filters apply conditions to all queries for a given entity. They’re often used for soft deletes or multi-tenancy. You configure them in OnModelCreating() using .HasQueryFilter().

Entity Framework C# Interview Questions

Here are some commonly asked Entity Framework in C# interview questions that test your understanding of how EF works within C# applications.

22. How do you use LINQ queries with Entity Framework in C#?

You write LINQ queries directly in C#. EF Core translates them to SQL at runtime. 

For example:

var activeUsers = context.Users.Where(u => u.IsActive).ToList();

These queries are easy to read and strongly typed.

23. What is the use of the DbSet<T> class in a C# EF application?

DbSet<T> represents a table in your database. It lets you query and perform CRUD operations on entities. Each DbContext contains a set of DbSet<T> properties mapped to entities.

24. How do you configure relationships using Fluent API in C#?

You configure relationships inside the OnModelCreating() method using Fluent API. Use methods like HasOne(), WithMany(), and HasForeignKey() to define relationships clearly. This approach gives more control than data annotations.

25. How do you handle transactions in C# when using Entity Framework?

Use BeginTransaction() with a using block. Commit with transaction.Commit() after SaveChanges(). If anything fails, call Rollback() to undo changes. This helps keep your data consistent.

Also Read - Top 30+ C# Interview Questions and Answers

Tips to Prepare for Entity Framework Interview

Here are some helpful tips to easily prepare for your Entity Framework interview – 

• Read the official EF Core docs and focus on real-world usage.
• Practice writing LINQ queries using different loading strategies.
• Understand model relationships and migrations deeply.
• Use mock projects to explore tracking, queries, and updates.
• Review differences between EF and EF Core.
• Practice commonly asked interview questions for Entity Framework.

Wrapping Up

These are the 25 most important Entity Framework interview questions and answers you should know. Understanding how EF works in real projects can help you speak with clarity and confidence in interviews.

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