Skip to main content

.NET6 Web API CRUD Operation With Entity Framework Core

In this article, we are going to do a small demo on AspNetCore 6 Web API CRUD operations.

What Is Web API:

Web API is a framework for building HTTP services that can be accessed from any client like browser, mobile devices, desktop apps.

In simple terminology API(Application Programming Interface) means an interface module that contains a programming function that can be requested via HTTP calls to save or fetch the data for their respective clients.

Some of the key characteristics of API:
  • Supports HTTP verbs like 'GET', 'POST', 'PUT', 'DELETE', etc.
  • Supports default responses like 'XML' and 'JSON'. Also can define custom responses.
  • Supports self-hosting or individual hosting, so that all different kinds of apps can consume it.
  • Authentication and Authorization are easy to implement.
  • The ideal platform to build REST full services.

Create A .NET6 Web API Application:

Let's create a .Net6 Web API sample application to accomplish our demo. We can use either Visual Studio 2022 or Visual Studio Code(using .NET CLI commands) to create any.Net6 application. For this demo, I'm using the 'Visual Studio Code'(using the .NET CLI command) editor.
CLI command
dotnet new webapi -o Your_Project_Name

Now let's explore default services or middleware that are in 'Program.cs':

Services in Program.cs:
builder.Services.AddControllers();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();
  • (Line:1) The 'AddControllers' service for API Controllers. This method will not work for the Views or Pages.
  • (Line: 2) The 'AddEndpointsApiExplorer' service for endpoint metadata.
  • (Line: 3) The 'AddSwagerGen' service for the Swagger.
Middlewares in Program.cs:
if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}
app.UseHttpsRedirection();
app.UseAuthorization();
app.MapControllers();
  • (Line: 3-4) The swagger middleware to load the swagger page.
  • (Line: 6) The 'UseHttpsRedirection' middleware to redirect the 'HTTP' request to 'HTTPS'.
  • (Line: 7) The user authorization middleware.
  • (Line: 8) The 'MapControllers' is an endpoint middleware that can direct the request to API's controllers.

SQL Query To Create A Sample Table:

Run the below command to create a sample table.
CREATE TABLE [dbo].[Cake] (
    [Id]          INT             IDENTITY (1, 1) NOT NULL,
    [Name]        VARCHAR (MAX)   NULL,
    [Price]       DECIMAL (18, 2) NULL,
    [Description] VARCHAR (MAX)   NULL
);

Entity Framework Core:

Entity Framework Core is an Object/Relational Mapping(ORM) framework. EF Core makes database communication more fluent and easy. The 'DatabaseContext' class acts as a database from our c# code, it will contain all registered tables as 'DbSet<TEntity>'(TEntity is any POCO class of a table).

In this demo, we are going to implement the 'Code First With Existing Database' technique. Creating the classes for an existing database is known as 'Code First With Existing Database'.

Install Entity Framework Core NuGet:

Now install the Entity Framework Core NuGet.
Package Manager Command
Install-Package Microsoft.EntityFrameworkCore -Version 6.0.1

.Net CLI Command
dotnet add package Microsoft.EntityFrameworkCore --version 6.0.1

Now install SQLServer which is Entity Framework Core dependent library.
Package Manager Command
Install-Package Microsoft.EntityFrameworkCore.SqlServer -Version 6.0.1

Package Manager Command
dotnet add package Microsoft.EntityFrameworkCore.SqlServer --version 6.0.1

Setup Entity Framework Core DatabaseContext:

Let's create a class that represents our table. So let's create folders like 'Data' and subfolder like 'Entities' and then add a class like 'Cake.cs'.
Data/Entities/Cake.cs:
namespace Dot6.API.Crud.Data.Entities;

public class Cake
{
    public int Id { get; set; }
    public string Name { get; set; }
    public decimal Price { get; set; }
    public string Description { get; set; }
}
To manage or control all the table classes we have to create DatabaseContext class. So let's create our context class like 'MyWorldDbContext.cs' in the 'Data' folder.
Data/MyWorldDbContext.cs:
using Dot6.API.Crud.Data.Entities;
using Microsoft.EntityFrameworkCore;

namespace Dot6.API.Crud.Data;

public class MyWorldDbContext : DbContext
{
    public MyWorldDbContext(DbContextOptions<MyWorldDbContext> options) : base(options)
    {

    }
    public DbSet<Cake> Cake { get; set; }
}
  • (Line: 6) The 'Microsoft.EntityFrameworkCore.DbContext' needs to be inherited by our 'MyWorldDbcontext' to act as a Database context class.
  • (Line: 8) The 'Microsoft.EntityFrameworkCore.DbContextOptions' is instance of options that we are going to register in 'Program.cs' like 'ConnectString', 'DatabaseProvider', etc.
  • (Line: 12) All our table classes must be registered inside of our Database context class with 'DbSet<T>' so that the entity framework core can communicate with the table of the database.
In the 'appsettings.Development.json' file add a connection string.
appsettings.Development.json:
"ConnectionStrings":{
    "MyWorldDbConnection":"your_connection"
}
Register the Database Context service in the 'Program.cs' file for dependency injection.
Program.cs:
builder.Services.AddDbContext<MyWorldDbContext>(options =>
{
	options.UseSqlServer(builder.Configuration.GetConnectionString("MyWorldDbConnection"));
});

Create A Sample API Controller:

In Web APIs controllers are the entry point for the HTTP requests. The 'Action' methods are logical units in the controller which get executed and return the response per request.

Now create a sample API controller like 'CakeController.cs' inside of the 'Controllers' folder.
Controllers/CakeController.cs:
using Dot6.API.Crud.Data;
using Microsoft.AspNetCore.Mvc;

namespace Dot6.API.Crud.Controllers;

[ApiController]
[Route("[controller]")]
public class CakeController: ControllerBase
{
    private readonly MyWorldDbContext _myWorldDbContext;
    public CakeController(MyWorldDbContext myWorldDbContext)
    {
        _myWorldDbContext = myWorldDbContext;
    }
}
  • (Line: 6) Decorated with the 'ApiController' attribute indicates that a type and all derived types(controllers) are used to server HTTP API responses. Controller decorated with this attribute is configured with features and behavior targets at improving the developer experience for building APIs
  • (Line: 7) Route to define our URL. The default expression '[Controller]' means name of the controller(eg: 'Cake'). We can define the custom name as the route that can be different from the controller name also.
  • (Line: 8) Our C# class to become a controller it needs to inherit 'Microsoft.AspNetCore.Mvc.ControllerBase'.
  • (Line: 10-14) Injected our DatabasContext into the controller.

Read Operation:

Let's create an Action method(which is a logical unit of the controller) of HTTP GET requests. Our job our action method to read the data from the database.
Controllers/CakeController.cs:
[HttpGet]
public async Task<IActionResult> GetAsync()
{
	var cakes = await _myWorldDbContext.Cake.ToListAsync();
	return Ok(cakes);
}
  • Here we can observe there is no 'Route[]' attribute defined on the action method. If our controller contains a single HTTP Get action method it is optional to add the 'Route[]' attribute. By convention, API will return the response. But if we have multiple action methods of the same HTTP types like 'GET', 'POST', 'PUT', 'Delete' then we have to define routes per action method explicitly.
  • (Line: 1) The 'HttpGet' attribute represents that our action method gets invoked for HTTP GET requests.
  • (Line: 2-6) Defined an asynchronous action method to return the collection of data.
  • (Line: 4) Fetching all records from the 'Cake' entity as an async call. The 'ToListAsync' is an extension from 'Microsoft.EntityFrameworkCore'.
  • (Line: 5) The 'Ok()' method creates an OkObjectResult, object that produces an StatusCodes.Status200Ok(which means 200 success) response.
Now run the application and use the swagger page tool to test our newly create endpoint.

Step1:

Step 2:

Step3:

Create Operation:

Let's create an action method for the HTTP POST request. Our action method job is to create a new record into the database.
Controllers/CakeController.cs:
[HttpGet]
[Route("get-cake-by-id")]
public async Task<IActionResult> GetCakeByIdAsync(int id)
{
	var cake = await _myWorldDbContext.Cake.FindAsync(id);
	return Ok(cake);
}

[HttpPost]
public async Task<IActionResult> PostAsync(Cake cake)
{
	_myWorldDbContext.Cake.Add(cake);
	await _myWorldDbContext.SaveChangesAsync();
	return Created($"/get-cake-by-id?id={cake.Id}", cake);
}
  • (Line: 9) The 'HttpPost' attribute represents our action method only gets invoked for the HTTP POST requests.
  • (Line: 10-15) Asynchronous action method for creating the new record.
  • (Line: 12) The 'Add' method on database context begins tracking the given entity. This will update the state of the database context as 'EntityState.Added' which means data is ready to save into the database.
  • (Line: 13) The 'SaveChangesAsync()' method saves our data into the database.
  • (Line: 14) The 'Created()' method creates a CreatedResult object that produces a status code of 201(created) as a response. This 'Created()' method first parameter will be URL for endpoint where we can get the newly created record, so to generate this URL I have created another HTTP GET action method at(Line: 1-7) that fetches data by the 'id' value. If you want you can use the 'Ok()' method as a return type from the HTTP POST action method as well.
Now run the application and test our HTTP POST endpoint.
Step1:

Step 2:

Step3:

Step4:

Update Operation:

Let's create an action method for the HTTP PUT requests. Our action method job is to update the record.
Controllers/CakeController.cs:
[HttpPut]
public async Task<IActionResult> PutAsync(Cake cakeToUpdate)
{
	_myWorldDbContext.Cake.Update(cakeToUpdate);
	await _myWorldDbContext.SaveChangesAsync();
	return NoContent();
}
  • (Line: 1) The 'HttpPut' represents our action method that gets invoked for HTTP PUT requests.
  • (Line: 2-7) Asynchronous method for updating the records.
  • (Line: 4) The 'Update()' method changes the Database context state as changed, which means data is ready to update. The 'Update()' method will update all columns for the record so make sure this is the case for the update or not. If you try to pass only a few columns of data then the remaining columns get updated with their default values. One more thing to remember the object should contain 'Id'(primary key) with value.
  • (Line: 5) The 'SaveChangesAsyn()' method saves the data into the database.
  • (Line: 6) The 'NoContent()' method creates a 'NoContentResult' object that produces an empty of status code 204(no content) as response.
Now run the application and test our HTTP PUT endpoint.
Step1:

Step2:

Step3:
Step4:

Delete Operation:

Let's create an action method of HTTP Delete request. Our action method job is to delete a particular(eg: by 'id' value) record from the database.
Controllers/CakeController.cs:
[Route("{id}")]
[HttpDelete]
public async Task<IActionResult> DeleteAsync(int id)
{
	var cakeToDelete = await _myWorldDbContext.Cake.FindAsync(id);
	if (cakeToDelete == null)
	{
		return NotFound();
	}
	_myWorldDbContext.Cake.Remove(cakeToDelete);
	await _myWorldDbContext.SaveChangesAsync();
	return NoContent();
}
  • (Line: 1) The '[Route]' attribute defined that means 'id' value should be passed as part of URL, and the '{}' is expression means any string defined inside of it will be the input parameter to the action method.
  • (Line: 2) The 'HttpDelete' attribute represents our action method getting invoked only for the HTTP Delete methods.
  • (Line: 3-13) Asynchronous action method for deleting the record from the database.
  • (Line: 5) Fetching the record that needs to be deleted from the database.
  • (Line: 6-9) Validating the record to be deleted. If no valid record in the database then we return the 'NotFound()' method whose status code is '404'.
  • (Line: 10-11) Removing the record from the database context. The 'SaveChangeAsync()' update the database context changes to the database.
  • (Line: 12) The 'NoContent()' status code is '204'.
Now run the application and test our HTTP DELETE endpoint.
Step1:


Step:2
Step3:

Support Me!
Buy Me A Coffee PayPal Me

Video Session:

Wrapping Up:

Hopefully, I think this article delivered some useful information on .NET6 Web API CRUD operations. I love to have your feedback, suggestions, and better techniques in the comment section below.

Refer:

Follow Me:

Comments

  1. Great Article!! Thanks.

    ReplyDelete
  2. Excellent Article with Crystal clear explanation

    ReplyDelete
  3. Great and Helpful! Thanks Dude

    ReplyDelete
  4. Michael AguilarnJune 1, 2022 at 7:33 AM

    Excelente artículo!muchas gracias

    ReplyDelete

Post a Comment

Popular posts from this blog

Blazor WebAssembly Custom Authentication From Scratch

In this article, we are going to explore and implement custom authentication from the scratch. In this sample, we will use JWT authentication for user authentication. Main Building Blocks Of Blazor WebAssembly Authentication: The core concepts of blazor webassembly authentication are: AuthenticationStateProvider Service AuthorizeView Component Task<AuthenticationState> Cascading Property CascadingAuthenticationState Component AuthorizeRouteView Component AuthenticationStateProvider Service - this provider holds the authentication information about the login user. The 'GetAuthenticationStateAsync()' method in the Authentication state provider returns user AuthenticationState. The 'NotifyAuthenticationStateChaged()' to notify the latest user information within the components which using this AuthenticationStateProvider. AuthorizeView Component - displays different content depending on the user authorization state. This component uses the AuthenticationStateProvider

How Response Caching Works In Asp.Net Core

What Is Response Caching?: Response Caching means storing of response output and using stored response until it's under it's the expiration time. Response Caching approach cuts down some requests to the server and also reduces some workload on the server. Response Caching Headers: Response Caching carried out by the few Http based headers information between client and server. Main Response Caching Headers are like below Cache-Control Pragma Vary Cache-Control Header: Cache-Control header is the main header type for the response caching. Cache-Control will be decorated with the following directives. public - this directive indicates any cache may store the response. private - this directive allows to store response with respect to a single user and can't be stored with shared cache stores. max-age - this directive represents a time to hold a response in the cache. no-cache - this directive represents no storing of response and always fetch the fr

A Small Guide On NestJS Queues

NestJS Application Queues helps to deal with application scaling and performance challenges. When To Use Queues?: API request that mostly involves in time taking operations like CPU bound operation, doing them synchronously which will result in thread blocking. So to avoid these issues, it is an appropriate way to make the CPU-bound operation separate background job.  In nestjs one of the best solutions for these kinds of tasks is to implement the Queues. For queueing mechanism in the nestjs application most recommended library is '@nestjs/bull'(Bull is nodejs queue library). The 'Bull' depends on Redis cache for data storage like a job. So in this queueing technique, we will create services like 'Producer' and 'Consumer'. The 'Producer' is used to push our jobs into the Redis stores. The consumer will read those jobs(eg: CPU Bound Operations) and process them. So by using this queues technique user requests processed very fastly because actually

Usage Of CancellationToken In Asp.Net Core Applications

When To Use CancellationToken?: In a web application request abortion or orphan, requests are quite common. On users disconnected by network interruption or navigating between multiple pages before proper response or closing of the browser, tabs make the request aborted or orphan. An orphan request can't deliver a response to the client, but it will execute all steps(like database calls, HTTP calls, etc) at the server. Complete execution of an orphan request at the server might not be a problem generally if at all requests need to work on time taking a job at the server in those cases might be nice to terminate the execution immediately. So CancellationToken can be used to terminate a request execution at the server immediately once the request is aborted or orphan. Here we are going to see some sample code snippets about implementing a CancellationToken for Entity FrameworkCore, Dapper ORM, and HttpClient calls in Asp.NetCore MVC application. Note: The sample codes I will show in

.Net5 Web API Managing Files Using Azure Blob Storage

In this article, we are going to understand the different file operations like uploading, reading, downloading, and deleting in .Net5 Web API application using Azure Blob Storage. Azure Blob Storage: Azure blob storage is Microsoft cloud storage. Blob storage can store a massive amount of file data as unstructured data. The unstructured data means not belong to any specific type, which means text or binary data. So something like images or pdf or videos to store in the cloud, then the most recommended is to use the blob store. The key component to creating azure blob storage resource: Storage Account:- A Storage account gives a unique namespace in Azure for all the data we will save. Every object that we store in Azure Storage has an address. The address is nothing but the unique name of our Storage Account name. The combination of the account name and the Azure Storage blob endpoint forms the base address for each object in our Storage account. For example, if our Storage Account is n

.Net5 Web API Redis Cache Using StackExchange.Redis.Extensions.AspNetCore Library

In this article, we are going to explore the integration of Redis cache in .Net5 Web API application using the 'StackExchange.Redis.Exntensions' library. Note:- Microsoft has introduced an 'IDistributedCache' interface in dotnet core which supports different cache stores like In-Memory, Redis, NCache, etc. It is simple and easy to work with  'IDistributedCache', for the Redis store with limited features but if we want more features of the Redis store we can choose to use 'StackExchange.Redis.Extensions'.  Click here for Redis Cache Integration Using IDistributedCache Interface . Overview On StackExchange.Redis.Extnesions Library: The 'StackExchange.Redis.Extension' library extended from the main library 'StackExchange.Redis'. Some of the key features of this library like: Default serialization and deserialization. Easy to save and fetch complex objects. Search key. Multiple Database Access Setup Redis Docker Instance: For this sampl

Part-1 Angular JWT Authentication Using HTTP Only Cookie[Angular V13]

In this article, we are going to implement a sample angular application authentication using HTTP only cookie that contains a JWT token. HTTP Only JWT Cookie: In a SPA(Single Page Application) Authentication JWT token either can be stored in browser 'LocalStorage' or in 'Cookie'. Storing JWT token inside of the cookie then the cookie should be HTTP Only. The HTTP-Only cookie nature is that it will be only accessible by the server application. Client apps like javascript-based apps can't access the HTTP-Only cookie. So if we use authentication with HTTP only JWT cookie then we no need to implement custom logic like adding authorization header or storing token data, etc at our client application. Because once the user authenticated cookie will be automatically sent to the server by the browser on every API call. Authentication API: To implement JWT cookie authentication we need to set up an API. For that, I had created a mock authentication API(Using the NestJS Se

Endpoint Routing In Asp.Net Core

How Routing Works In  Core 2.1 And Below Versions?: In Asp.Net Core routing is configured using app.UseRouter() or app.UseMvc() middleware. app.UseMvc(routes => { routes.MapRoute( name: "default", template: "{controller=Home}/{action=Index}/{id?}"); }); Here in Dotnet Core version 2.1 or below versions on the execution of route middleware request will be navigated appropriate controller matched to the route. An operation or functionality which is dependent on route URL or route values and that need to be implemented before the execution of route middleware can be done by accessing the route path from the current request context as below app.Use(async (context, next) => { if(context.Request.Path.Value.IndexOf("oldvehicle") != -1) { context.Response.Redirect("vehicle"); } else { await next(); } }); app.UseMvc(routes => { routes.MapRoute( name: "vehicleRoute", template: "vehicle", defaul

Unit Testing Asp.NetCore Web API Using xUnit[.NET6]

In this article, we are going to write test cases to an Asp.NetCore Web API(.NET6) application using the xUnit. xUnit For .NET: The xUnit for .Net is a free, open-source, community-focused unit testing tool for .NET applications. By default .Net also provides a xUnit project template to implement test cases. Unit test cases build upon the 'AAA' formula that means 'Arrange', 'Act' and 'Assert' Arrange - Declaring variables, objects, instantiating mocks, etc. Act - Calling or invoking the method that needs to be tested. Assert - The assert ensures that code behaves as expected means yielding expected output. Create An API And Unit Test Projects: Let's create a .Net6 Web API and xUnit sample applications to accomplish our demo. We can use either Visual Studio 2022 or Visual Studio Code(using .NET CLI commands) to create any.Net6 application. For this demo, I'm using the 'Visual Studio Code'(using the .NET CLI command) editor. Create a fo