In Web API, a controller is an object that handles HTTP requests.
Introduction
In this article we will see how to add a Web API controller..In this context we’ll add a Web API controller that supports CRUD (create, read, update, and delete) operations on Books.
Objective
The Objective of this article is to show how the controller will use Entity Framework to communicate with the database layer. Only administrators will be able to use this controller. Customers will access the Books through another controller.Before we proceed please have a look at
Part 2 article
- Step1 : In Solution Explorer, right-click the Controllers folder. Select Add and then Controller.
Enter the details as shown
If the Model class drop-down does not show any model classes as shown above, make sure you compiled the project and add it again.
Here we can see the new solution structure
Modify the context class as shown below
using System.Data.Entity;
namespace BooksStore.Models
{
public class OrdersContext : DbContext
{
// You can add custom code to this file. Changes will not be overwritten.
//
// If you want Entity Framework to drop and regenerate your database
// automatically whenever you change your model schema, add the following
// code to the Application_Start method in your Global.asax file.
// Note: this will destroy and re-create your database with every model change.
//
// System.Data.Entity.Database.SetInitializer(new System.Data.Entity.DropCreateDatabaseIfModelChanges<BooksStore.Models.OrdersContext>());
//This name refers to the connection string that was added to Web.config.
public OrdersContext() : base("name=OrdersContext")
{
}
//A DbSet represents a set of entities that can be queried. Here is the complete listing
public DbSet<Book> Books { get; set; }
//New code
public DbSet<Order> Orders { get; set; }
public DbSet<OrderDetail> OrderDetails { get; set; }
}
}
- Step2 : Now lets add Database Intializer
In Solution Explorer, right-click the Models folder and create a new class named OrdersContextInitializer and add the following Implementation
using System.Collections.Generic;
using System.Data.Entity;
namespace BooksStore.Models
{
//By inheriting from the DropCreateDatabaseIfModelChanges class, we are telling Entity Framework to drop the database whenever we modify the model classes. When Entity Framework creates (or recreates) the database, it calls the Seed method to populate the tables.
public class OrdersContextInitializer : DropCreateDatabaseIfModelChanges<OrdersContext>
{
protected override void Seed(OrdersContext context)
{
var books = new List<Book>()
{
new Book() { Name = "Practical ASP.NET Web API", DealPrice = 1.39M, SellingPrice = .88M },
new Book() { Name = "Pro ASP.NET 4.5 in VB, 5th Edition", DealPrice = 16.99M, SellingPrice = 40 },
new Book() { Name = "Beginning ASP.NET MVC 4", DealPrice = 6.99M, SellingPrice = 4.05M }
};
books.ForEach(p => context.Books.Add(p));
context.SaveChanges();
var order = new Order() { Customer = "Sagar" };
var od = new List<OrderDetail>()
{
new OrderDetail() { Book = books[0], Quantity = 2, Order = order},
new OrderDetail() { Book = books[1], Quantity = 4, Order = order }
};
context.Orders.Add(order);
od.ForEach(o => context.OrderDetails.Add(o));
context.SaveChanges();
}
}
}
Conclusion
In this article we have learned how to create web API controller in our project
Reference
http://www.asp.net/web-api/overview/getting-started-with-aspnet-web-api/tutorial-your-first-web-api