Entity Framework Core (EF Core) is an Object-Relational Mapping (ORM) framework provided by Microsoft for .NET Core and .NET 8 applications. It enables developers to work with relational databases using .NET objects, allowing for a more object-oriented approach to database interaction. Here’s a comprehensive guide to using Entity Framework Core in .NET:
1. Installation and Setup:
To get started with Entity Framework Core in a .NET 8 application:
a. Install EF Core:
dotnet add package Microsoft.EntityFrameworkCore
b. Install Database Provider:
Choose a database provider such as SQL Server, SQLite, PostgreSQL, MySQL, etc., and install its EF Core package. For example, for SQL Server:
dotnet add package Microsoft.EntityFrameworkCore.SqlServer
2. Define Database Context:
Create a class that inherits from `DbContext` to represent your database session and define your database tables as `DbSet` properties within it.
using Microsoft.EntityFrameworkCore;
public class MyDbContext : DbContext
{
public DbSet<User> Users { get; set; }
// Add other DbSets for your entities here
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
optionsBuilder.UseSqlServer("YourConnectionString");
}
}
3. Define Entities:
Create classes to represent your database tables. These classes will become the entities managed by EF Core.
public class User
{
public int Id { get; set; }
public string Name { get; set; }
public int Age { get; set; }
}
4. Migrations:
Migrations are used to create and update the database schema based on your entity classes.
a. Add Initial Migration:
dotnet ef migrations add InitialCreate
b. Update Database:
dotnet ef database update
5. Querying Data:
Use LINQ queries to retrieve data from the database.
using (var context = new MyDbContext())
{
var users = context.Users.Where(u => u.Age > 18).ToList();
}
6. Adding, Updating, and Deleting Data:
Use EF Core methods to perform CRUD operations on your entities.
using (var context = new MyDbContext())
{
// Add new user
var newUser = new User { Name = "John", Age = 25 };
context.Users.Add(newUser);
context.SaveChanges();
// Update user
var userToUpdate = context.Users.Find(1);
userToUpdate.Name = "Updated Name";
context.SaveChanges();
// Delete user
var userToDelete = context.Users.Find(1);
context.Users.Remove(userToDelete);
context.SaveChanges();
}
7. Advanced Features:
Explore additional features like relationships, eager loading, lazy loading, transactions, stored procedures, etc., as needed.
8. Unit Testing:
Write unit tests for your data access layer using in-memory databases or mocking frameworks.
9. Performance Optimization:
Optimize performance by using techniques like batch processing, caching, query optimization, etc.
10. Error Handling and Logging:
Implement error handling and logging mechanisms to handle exceptions and log relevant information.
By following this comprehensive guide, you’ll be able to effectively use Entity Framework Core in your .NET applications for database interactions.