Entity Framework (EF) is like a magic translator that helps your C# code talk to a database. Imagine you’re the potato boss 🥔👑, and you give instructions in English, but the warehouse only understands SQL.

💡 EF takes your C# commands and translates them into SQL so that the database understands them.

Using SQL is like giving detailed, step-by-step instructions to the warehouse, such as:

• 🥔 “Add a new potato to the inventory.”
• 🥔 “Check how many golden potatoes we have.”
• 🥔 “Update the price of purple potatoes.”
• 🥔 “Remove rotten potatoes from the warehouse.”

With Entity Framework, you don’t need to write all those instructions in SQL! You can give the same instructions directly in C#, and EF does the hard work for you! 💡✨

Here’s a step-by-step breakdown:

1. 🥔 Model Your Data – Create classes to represent your database tables.
2. 🥔 Set Up the Database Context – Define a bridge that connects your classes to the database.
3. 🥔 Perform CRUD Operations – Use simple C# commands to manage the data.

To use Entity Framework in your project, you’ll need to install a package.

1. Open Visual Studio.
2. Open the Package Manager Console:
   • Click on Tools → NuGet Package Manager → Package Manager Console.
3. Run the following command:

Install-Package Microsoft.EntityFrameworkCore

4. Also install the SQL Server provider:

Install-Package Microsoft.EntityFrameworkCore.SqlServer

5. If you plan to generate migrations, install this:

Install-Package Microsoft.EntityFrameworkCore.Tools

The data model defines how the database looks. It’s like making a blueprint of your potato warehouse with different shelves for various types of potatoes.

public class Potato
{
    public int Id { get; set; }         // Unique ID
    public string Name { get; set; }    // Potato name
    public string Type { get; set; }    // Type of potato
    public double PricePerKg { get; set; }  // Price per kg
}

✅ Explanation:

• Id – Primary key that uniquely identifies a potato.
• Name – The name of the potato.
• Type – The variety or type of potato.
• PricePerKg – Price of the potato per kilogram.

The DbContext class is like a warehouse manager 🏢 who controls how data moves in and out of the warehouse.

using Microsoft.EntityFrameworkCore;

public class PotatoContext : DbContext
{
    public DbSet<Potato> Potatoes { get; set; }  // Potatoes table

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        // Database connection string
        optionsBuilder.UseSqlServer(@"Server=localhost;Database=PotatoDB;User Id=sa;Password=potato123;");
    }
}

✅ Explanation:

• DbSet<Potato> – Represents the Potatoes table in the database.
• OnConfiguring – Configures the database connection using a connection string.

To create the database using Entity Framework, we need to generate migrations. Think of it like giving the warehouse blueprint to the workers before building starts. 🏗️

Add-Migration InitialCreate

✅ Explanation:

• This generates a migration file that describes how to create the Potatoes table.

Update-Database

✅ Explanation:

• This applies the migration and creates the PotatoDB database.

Now that our Potato Warehouse is ready, we can start adding, reading, updating, and deleting data using C# commands!

To add a new potato to the warehouse:

using System;

class Program
{
    static void Main()
    {
        using (var context = new PotatoContext())
        {
            var newPotato = new Potato
            {
                Name = "Golden Potato",
                Type = "Yukon Gold",
                PricePerKg = 3.5
            };

            context.Potatoes.Add(newPotato);
            context.SaveChanges();

            Console.WriteLine("✅ Potato added successfully!");
        }
    }
}

✅ Explanation:

• context.Potatoes.Add(newPotato) – Adds the new potato.
• context.SaveChanges() – Saves the changes to the database.

✅ Potato added successfully!

To get all potatoes in the warehouse:

using System;
using System.Linq;

class Program
{
    static void Main()
    {
        using (var context = new PotatoContext())
        {
            var potatoes = context.Potatoes.ToList();

            foreach (var potato in potatoes)
            {
                Console.WriteLine($"🥔 {potato.Name} ({potato.Type}) - {potato.PricePerKg} per kg");
            }
        }
    }
}

✅ Explanation:

• context.Potatoes.ToList() – Retrieves all the potatoes.

🥔 Golden Potato (Yukon Gold) - 3.5 per kg
🥔 Sweet Potato (Beauregard) - 2.0 per kg

To update the price of a potato:

using System;
using System.Linq;

class Program
{
    static void Main()
    {
        using (var context = new PotatoContext())
        {
            var potato = context.Potatoes.FirstOrDefault(p => p.Name == "Golden Potato");

            if (potato != null)
            {
                potato.PricePerKg = 4.0;
                context.SaveChanges();
                Console.WriteLine("✅ Potato price updated successfully!");
            }
            else
            {
                Console.WriteLine("⚠️ Potato not found.");
            }
        }
    }
}

✅ Explanation:

• context.Potatoes.FirstOrDefault() – Finds the potato by name.
• context.SaveChanges() – Saves the updated data to the database.

✅ Potato price updated successfully!

To remove a potato from the warehouse:

using System;
using System.Linq;

class Program
{
    static void Main()
    {
        using (var context = new PotatoContext())
        {
            var potato = context.Potatoes.FirstOrDefault(p => p.Name == "Golden Potato");

            if (potato != null)
            {
                context.Potatoes.Remove(potato);
                context.SaveChanges();
                Console.WriteLine("✅ Potato removed successfully!");
            }
            else
            {
                Console.WriteLine("⚠️ Potato not found.");
            }
        }
    }
}

✅ Explanation:

• context.Potatoes.Remove(potato) – Removes the potato from the database.

✅ Potato removed successfully!

You can use LINQ (Language Integrated Query) to filter and query data more efficiently. It’s like asking very specific questions about your potatoes. 🌟

var expensivePotatoes = context.Potatoes.Where(p => p.PricePerKg > 3.0).ToList();

✅ Explanation:

• Where(p => p.PricePerKg > 3.0) – Filters potatoes that are more expensive than 3.0 per kg.