Using Entity Framework with pre-existing database tables

Given

• A pre-existing database called Inventory
• A table named Product in the database

Objective

Access the Product table using entity framework

Steps

1. Create a console application
2. Install EntityFramework package using Nuget
3. Add the connection string to App.config

<connectionStrings>

    <add name="InventoryDbContext" connectionString="Data Source=(LocalDb)\v11.0;Initial Catalog=Inventory;Integrated Security=True;Pooling=False"

         providerName ="System.Data.SqlClient"/>

  </connectionStrings>

Code

// Class for accessing the rows in the table

// EF would normally look for "Products" table

// Tell EF to look for "Product" table

[Table("Product")]      

public class Product

{

  public int Id { get; set; }

  public string PartNumber { get; set; }

  public string PartName { get; set; }

}

// database context for access

public class InventoryDbContext : DbContext

{

  static InventoryDbContext()

  {

    // Turn off EF's database initialization (our database is pre-existing)

    Database.SetInitializer<InventoryDbContext>(null);

  }

  // Set with access to rows in the Product table

  public IDbSet<Product> Products { get; set; }

}

class Program

{

  

  static void Main(string[] args)

  {

    using (var ctx = new InventoryDbContext())

    {

      var products = ctx.Products.ToList();

      products.ForEach(p => 

        Console.WriteLine("{0}: {1}, {2}", p.Id, p.PartNumber, p.PartName));

    }

    Console.ReadKey();

  }

}

Output

1: 0001, Widget
2: 0002, Binder
3: 0003, Marker