Introduction

This tutorial will show you how to build a.NET 6 Web API using Entity Framework core, SQL, and API endpoints. This will allow API clients to perform CRUD on data stored in the database.

We will use the database-first approach in our demo application. We will create a table first in the SQL database, and then we’ll use an entity framework for DBContext.

What is Web API?

Web APIs are a platform that allows the development of HTTP services. These services can be accessed from a variety of client-side software, such as mobile phones, web browsers, and desktop programs. It allows multiple applications to interact and exchange data.

Developers can create API functions that are available through HTTP requests. This function allows your clients to access and retrieve specific data that you have made available through the API.

Key features of API

• Supports HTTP verbs such as GET, POST PUT DELETE etc. which allows clients perform different actions on data
• Standard formats such as XML or JSON are supported by default, which helps exchange data between client and server.
• API allows for the definition of custom data, allowing you to customize data according to client requirements
• You can use APIs that are hosted either by yourself or by a third party.
• This allows for easy authentication and authorization, which protects data and helps to control API operations.
• API is the ideal platform to build RESTful web services. These services are flexible, scalable and easy to maintain.

Why do we need Web API?

Today, people use multiple devices, such as smartphones and tablets. To reach all users, you need more than just a web application. An API is needed to expose these data services to the various browsers and apps. By adding a web API, it is easier to connect the two ends and to update.

We need a Web API in this case to manage database interactions and the business logic between an Android app and an iOS application.

The Web API project allows all three applications to communicate with the database. It handles database interactions, and makes sure that the database cannot be accessed directly through websites or applications.

Web APIs are an important tool for modern application development because they allow secure and efficient communication among different devices and applications.

Create SQL Database and Table.

Moving to the next section of the Web API in .NET 6.0 Tutorial, create New Database ProductDB in SQL, and execute the below script to create a Product table.

                    
                        USE [ProductDB]
GO

SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE TABLE [dbo].[Products](
	[Id] [int] IDENTITY(1,1) NOT NULL,
	[Name] [varchar](50) NOT NULL,
	[Description] [varchar](250) NULL,
	[Price] [decimal](18, 2) NOT NULL,
PRIMARY KEY CLUSTERED 
(
	[Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]
GO

                    
                   

Create DBContext and Model

Now, let’s move on to the next step of our web API tutorial, where we will create the DBContext and Model.

We are using the database first approach of the entity framework.

We have created a database table, and using the Scaffold-DbContext command of the entity framework; we will create the required class in the C# project.

Open Package Manager Console (Tool => Package Manager => Package Manager Console) and run below command:

Scaffold-DbContext “Server=SERVERNAME;Database=ProductDB;Integrated Security=True” Microsoft.EntityFrameworkCore.SqlServer -OutputDir Models

Replace SERVERNAME with your database server name.

Once this command is executed, the Model folder is created in the project solution. Model folder contains two files, ProductDBContext.cs and Product.cs.

ProductDBContext.cs is responsible for database interaction, and Product.cs is a model of the Products table.

Remove OnConfiguring() method from ProductDBContext.cs; it contains a database connection string and is not a good practice. We will add the connection string in the appsettings.json file.

Also remove ProductDBContext() constructor from this file.

Launch API

Finally, we are done with Web API in .NET 6.0 tutorial. Now, it’s time to launch this API, press F5. As we are using Swagger UI, we can execute API directly.

We can see GET, POST, PUT AND DELETE under Products. We can execute different API methods from this page itself.

Finally, we are done with Web API in .NET 6.0 tutorial. Now, it’s time to launch this API, press F5. As we are using Swagger UI, we can execute API directly. We can see GET, POST, PUT AND DELETE under Products. We can execute different API methods from this page itself.