Entity Framework Core Introduction in ASP.NET Core
💡 Concept Name
Entity Framework Core Introduction in ASP.NET Core
📘 Quick Intro
Entity Framework Core (EF Core) is a lightweight, extensible, and cross-platform ORM for .NET Core. It enables developers to interact with relational databases using strongly-typed C# classes.
🧠 Analogy / Short Story
Imagine trying to speak to a French-only database in English. Normally, you'd need a translator (SQL). EF Core acts like a smart assistant who translates your C# into fluent SQL and interprets database results back into C#. It handles the entire communication bridge.
🔧 Technical Explanation
EF Core is a modern ORM that supports Code First and Database First approaches. It maps your C# models to database tables using a context class (DbContext) and supports LINQ for querying. It also supports automatic migrations, change tracking, and database seeding.
🎯 Purpose & Use Case
- ✅ Quickly interact with databases using C# classes
- ✅ Write LINQ instead of raw SQL
- ✅ Support for database migrations and schema updates
- ✅ Cross-database support (SQL Server, PostgreSQL, SQLite, etc.)
- ✅ Ideal for building enterprise ASP.NET Core apps
💻 Real Code Example
// Model class
public class Product
{
public int Id { get; set; }
public string Name { get; set; }
}
// DbContext class
public class AppDbContext : DbContext
{
public DbSet<Product> Products { get; set; }
public AppDbContext(DbContextOptions<AppDbContext> options) : base(options) { }
}
// Register in Program.cs
builder.Services.AddDbContext<AppDbContext>(options =>
options.UseSqlServer(builder.Configuration.GetConnectionString("DefaultConnection")));
❓ Interview Q&A
Q1: What is EF Core?
A: It's an ORM that simplifies database operations using C# models.
Q2: What is DbContext?
A: It's the primary class used to interact with the database.
Q3: How do you create tables using EF Core?
A: Use Code First approach and run migrations.
Q4: What is Code First vs Database First?
A: Code First starts with C# classes, DB First uses an existing DB.
Q5: What are migrations in EF Core?
A: They're a way to evolve your schema with code updates.
Q6: Can EF Core work with PostgreSQL?
A: Yes, using the Npgsql provider.
Q7: Does EF Core support lazy loading?
A: Yes, but it must be explicitly enabled.
Q8: What is a DbSet?
A: It represents a table in your database mapped to a model.
Q9: Is EF Core better than Dapper?
A: EF Core is feature-rich, Dapper is faster for raw queries.
Q10: How do you update data using EF Core?
A: Modify the entity and call SaveChanges().
Q1: What is the primary purpose of DbContext in EF Core?
- A. Acts as database schema
- B. Acts as a bridge between model and database
- C. Logs database errors
- D. Generates SQL scripts
Q2: Which NuGet package is used to install EF Core with SQL Server?
- A. Microsoft.EntityFramework
- B. EFCore.Standard
- C. Microsoft.EntityFrameworkCore.SqlServer
- D. System.Data.EF
💡 Bonus Insight
EF Core is not just for SQL Server — it supports SQLite (for mobile), PostgreSQL, MySQL, and even Cosmos DB. This makes it an incredibly versatile ORM across multiple platforms.
📄 PDF Download
Need a handy summary for your notes? Download this topic as a PDF!