Integrating C# with databases using Entity Framework

Entity Framework Integration

Integrating C# with databases using Entity Framework involves several steps:

1. Create a new project in Visual Studio and add the Entity Framework NuGet package to it.
2. Create a conceptual model of your data using classes and properties. These classes will be mapped to the database tables and properties will be mapped to the columns.
3. Create a database context class that will act as a bridge between the conceptual model and the database. This class should inherit from the DbContext class provided by EF.
4. Use the context class to interact with the database. EF provides a set of methods such as Add, Update, Remove and SaveChanges that can be used to perform CRUD operations on the data.
5. Use LINQ to query the data using the context class.
6. Use a connection string to connect to the database.
7. Optionally, use migrations to create and update the database schema.

using System;
using System.Linq;
using Microsoft.EntityFrameworkCore;

//1. Create a new project in Visual Studio and add the Entity Framework NuGet package to it.

//2. Create a class for the data model
public class Person
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int Age { get; set; }
}

//3. Create a database context class
public class MyContext : DbContext
{
    public DbSet<Person> People { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder.UseSqlServer("Server=(localdb)\\mssqllocaldb;Database=mydb;Trusted_Connection=True;");
    }
}

//4. Use the context class to interact with the database
class Program
{
    static void Main()
    {
        using (var context = new MyContext())
        {
            // Add a new person to the database
            var person = new Person { Name = "John Doe", Age = 30 };
            context.People.Add(person);
            context.SaveChanges();

            // Query the database
            var people = context.People.Where(p => p.Age > 25).ToList();

            // Update a person
            var firstPerson = context.People.First();
            firstPerson.Name = "Jane Doe";
            context.SaveChanges();

            // Delete a person
            context.People.Remove(firstPerson);
            context.SaveChanges();
        }
    }
}

Please note that for this code to work, you need to have SQL Server installed on your machine, this is just an example the connection string may change depending on the server and the database you are connecting to.

This is a simple example but it demonstrates the basic operations, you can use the context class to perform more complex queries and procedures, and it also provides a way to handle database relationships, such as one-to-many, many-to-many, and many-to-one, in a more natural way.

Once these steps are completed, you can use the context class to interact with the database in a more object-oriented way, rather than writing raw SQL queries.

Entity Framework Core Components