Performing CRUD operations using ASP.NET Web API - Part 1

In one of my previous ASP.NET Web API Tutorial, I explained 3 simple steps to create your first ASP.NET Web API service. In this article, I’ll try to perform all CRUD (Create, Read, Update, Delete) operations using Microsoft ASP.NET Web API.

I already has discussed that ASP.NET Web API is a framework that simplifies the creation of HTTP services. We can build loosely coupled services as Web API follows REST architecture. Another advantage of using HTTP services is that it can be consumed by a wide range of clients.As we are going to perform CRUD (Create, Read, Update, Delete) operations in this Web Development article using HTTP services, we must understand that these how these operations map to basic HTTP verbs.

Create -> POST
Read -> GET
Update -> PUT
Delete -> DELETE

You can follow here to get a comprehensive list of FAQs or ASP.NET Web API Interview Questions. This Web API Tutorial is designed to grasp the core Web API Concepts with few tricky Interview Questions List.

Building a Real World Application using ASP.NET Core and Angular 2

In order to get start with coding, please create a new ASP.NET MVC 4 Project using Visual Studio and choose Web API template. When the new project is created successfully, you can easily find “Model”, “View” and “Controller” folders inside it.

First of all, we will be creating a new domain model class inside the model folder say “Student.cs” as:

public class Student
 {
          public string StudentID { get; set; }
          public string FirstName { get; set; }
          public string LastName { get; set; }
 }

public class Student

{

public string StudentID { get; set; }

public string FirstName { get; set; }

public string LastName { get; set; }

}

For a better and clean separation, we will add another class “StudentRepository.cs” which will actually perform the CRUD operations. For the purpose of simplicity, I am not going to write complete database interaction code here. You can have implementation of your choice, for example, LINQ or ADO.NET Entity Framework etc.

public class StudentRepository
 {
         private static List<Student> students;
         
         public static List<Student> GetAllStudents()
         {
                   //Code logic to get all students.
          }
 
          public static Student GetStudent(string studentID)
         {
                  //Code Logic to get all students.
          }
 
          public static void RemoveStudent(string studentID)
          {
                  //Code Logic to delete a student
          }
 
           public static void AddStudent(Student student)
           {
                  //Code Logic to Add a new student.
            }
 
            public static void UpdateStudent(Student student)
            {
                  //Code Logic to Update a student.
            }
  }

public class StudentRepository

{

private static List<Student> students;

public static List<Student> GetAllStudents()

{

//Code logic to get all students.

}

public static Student GetStudent(string studentID)

{

//Code Logic to get all students.

}

public static void RemoveStudent(string studentID)

{

//Code Logic to delete a student

}

public static void AddStudent(Student student)

{

//Code Logic to Add a new student.

}

public static void UpdateStudent(Student student)

{

//Code Logic to Update a student.

}

Now, its time to add controller class to your project. In controller folder, you will find two controller classes by default i.e. HomeController.cs and ValuesController.cs. Add a new controller “StudentsController.cs” under “Controller” folder. Following will be the code for it.

public class StudentsController : ApiController
 {
          public List<Student> Get()
          {
                  return StudentRepository.GetAllStudents();
          }
 
           public Student Get(string id)
           {
                   return StudentRepository.GetStudent(id);
           }
 
           public void Post(Student Student)
           {
                   StudentRepository.AddStudent(Student);
            }
 
            public void Put(Student Student)
            {
                   StudentRepository.UpdateStudent(Student);
            }
 
             public void Delete(string id)
             {
                    StudentRepository.RemoveStudent(id);
             }
 }

public class StudentsController : ApiController

{

public List<Student> Get()

{

return StudentRepository.GetAllStudents();

}

public Student Get(string id)

{

return StudentRepository.GetStudent(id);

}

public void Post(Student Student)

{

StudentRepository.AddStudent(Student);

}

public void Put(Student Student)

{

StudentRepository.UpdateStudent(Student);

}

public void Delete(string id)

{

StudentRepository.RemoveStudent(id);

}

In this ASP.NET Web API Tutorial, we have completed the code for performing CRUD operations using ASP.NET Web API. In second part of this article, we will focus on writing the code for consuming the service.

Next : ASP.NET Web API Service – Part 2

Do you want to verify your ASP.NET MVC skill? Answer the below question.

Please look into following piece of code:

[ActionName(“GetById”)]

public ActionResult GetEmployeeById()
{
//Code logic here.

return View();
}
What’s true about the above code.

A. “GetEmployeeById” action method with be identified and called by name “GetEmployeeById”.
B. “GetEmployeeById” action method with be identified and called by name “GetById”.
C. Above code will generate an error because of wrong return type.
D. Action method can’t be called because of duplicate action method names.

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Correct Answers: B

12 thoughts on “Performing CRUD operations using ASP.NET Web API – Part 1”

Braj Panda January 17, 2014

Nice post. By the way, I would like to know how you got those code blocks in that grey box. Can you please share the trick? Thanks in advance.
1. Imran Ghani January 17, 2014
  
  Thanks Braj. In order to gray code box, you need to understand HTML. I modified the HTML.
WebdevTutorial September 10, 2014

Your is very nice article about Performing CRUD operations using ASP.NET Web API.
Can you please share the client code to make call to webAPI.
Thanks
Shrirang
1. WebdevTutorial September 10, 2014
  
  Dear Shrirang,
  Thanks for your appreciation.
  Part 2 of this tutorial is about consuming ASP.NET Web API with client code.
  
  Thanks
  Imran
WebdevTutorial November 13, 2014

I believe you are making some mistake while calling a method. This type of error occurs normally when someone calls a method at class level instead of making call inside a method.
If unable to resolve, please share the code where you’r getting this error.
1. swapna November 14, 2014
  
  hello,
  ur explanation is really very good,my code got executed..thanx
  hope you will respond to my further queries !!
WebdevTutorial November 13, 2014

This error clearly indicates that “Product” is inaccessible in your code. Please make sure that your model “Product” is accessible in controller code? Verify the namespaces if you explicitly have given?
Divya MK March 17, 2015

Your tutorial is very nice.
Can you please share the source code,implementing any of the method in ‘StudentRepository’ class.I am confused on how to implement CRUD operation using linq or ADO.NET entity framework
Divya MK March 17, 2015

Your tutorial is very nice.
Can you please share the source code,implementing any of the method in ‘StudentRepository’ class.I am confused on how to implement CRUD operation using linq or ADO.NET entity framework
Cipher Coder July 1, 2017

I want to see some articles explaining CRUD in asp .net Web API 2 using angular 2, in the same lucid and beautiful manner as this article is.. so.. which one ..?
lizyantoni November 15, 2017

This gives a clear basic understanding.
Thanks
1. WebdevTutorial November 15, 2017
  
  Thanks Lizyantoni for your appreciation.
  You can follow the link for Practical Guide to ASP.NET Web API with all related concepts and implementations here:
  http://www.webdevelopmenthelp.net/2014/02/practical-guide-asp-net-web-api.html
  
  Also, for updated version i.e. ASP.NET Core Web API, you can follow the below Series of tutorials here.
  http://www.webdevelopmenthelp.net/2017/09/asp-net-core-web-api-tutorial-part-1.html

Comments are closed.

Performing CRUD operations using ASP.NET Web API – Part 1

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12 thoughts on “Performing CRUD operations using ASP.NET Web API – Part 1”