asp.net-web-api OData with Asp.net Web API Enable Entity Framework

Example

For this tutorial, we'll use Entity Framework (EF) Code First to create the back-end database.

Web API OData does not require EF. Use any data-access layer that can translate database entities into models.

First, install the NuGet package for EF. From the Tools menu, select NuGet Package Manager > Package Manager Console. In the Package Manager Console window, type:

Install-Package EntityFramework

Open the Web.config file, and add the following section inside the configuration element, after the configSections element.

<configuration>
  <configSections>
    <!-- ... -->
  </configSections>

  <!-- Add this: -->
  <connectionStrings>
    <add name="ProductsContext" connectionString="Data Source=(localdb)\v11.0; 
        Initial Catalog=ProductsContext; Integrated Security=True; MultipleActiveResultSets=True; 
        AttachDbFilename=|DataDirectory|ProductsContext.mdf"
      providerName="System.Data.SqlClient" />
  </connectionStrings>

This setting adds a connection string for a LocalDB database. This database will be used when you run the app locally.

Next, add a class named ProductsContext to the Models folder:

using System.Data.Entity;
namespace ProductService.Models
{
    public class ProductsContext : DbContext
    {
        public ProductsContext() 
                : base("name=ProductsContext")
        {
        }
        public DbSet<Product> Products { get; set; }
    }
}

In the constructor, "name=ProductsContext" gives the name of the connection string.