Integration of .Net Web Api with Entity Framework – STEP BY STEP

 

There are more than one ways of integrating a .Net application with Entity Framework.

In this process, we shall be using

1. Web Api’s scaffolded template for controller creation
2.  Code First Approach in Entity Framework

Pre-requisites:

1.             This integration is done using .Net 6   

                2.  Using Visual Studio 2022

Process

1.      Create a Web Api Core project using C#. File => New Project => Asp.net Core Web API

a.       

 

2.      The project created should look like this in the solution explorer. Here we have named the project as ForEF.

a.      

3.      Create a new API controller using the scaffolded template for Entity Framework. Right-click on Controllers folder => Add => Controller

a.      

 

 

4.      Next choose the API controller => Actions using Entity Framework

a.      

b.      

 

5.      On clicking add, it should begin installing Entity Framework Code packages from nuget.

 

a.       

 

b.      You might get an error as below.

                                                               i.      

 

c.       In this case, please do the following. Close the dialogs for controller creation. In the solution explorer, Right-Click on Dependencies folder of your project => Manage Nuget Packages

                                                               i.      

 

d.      You will notice that the missing package is already installed.

                                                               i.      

 

6.      Open the file WeatherForecast.cs , from the solution Explorer.  This file could be any file that acts as the model for your application. A model file is a file that contains

a.      A default constructor

b.       Only properties

c.       

 

7.      Add a property to it, and mark it with the [Key] Attribute.

a.      

 

b.      The property marked with [Key] attribute, will become the primary key in the database table. The model class becomes, the table name while the properties become columns of the table

8.      Now, repeat the steps 3, 4. Your controller should be created successfully.

9.      In the Solution Explorer, find the file called “appSettings.json” and open it. In this file, we will need to provide the Database name as part of “Database” Setting. Please refer screenshot below. Here we have named the database as “ForEF”. Save the file and close.

a.      

10.  To automatically migrate to the database, please follow the two commands.

a.      Open Package Manager Console. Tools Menu => Nuget Package Manager => Package Manager Console

                                                               i.      

b.      This will open the package manager console as below. Two things must be done before adding any commands

                                                              i.      Set your project as the Startup Project. [Right-click on your project => Set As Startup Project]

                                                             ii.      In the Package Manager Console, your project should be the selected project in the Dropdown list

                                                           iii.     

 

c.       Build your project manually. [Right-click on your project => Build]

d.      In the Package Manager Console, add the following commands

                                                              i.      To create a migration.

1.      Add-Migration

a.      

 

                                                             ii.      Once this command completes successfully, add in the next command, to generate a database in MS SQL Server Express. The command is as follows

1.      Update-Database

a.       

 

                                                           iii.      The migration should be successful.

11.  ALTERNATIVE STE. USE IF ABOVE FAILS: If the Package Manager Console commands fail, by showing a build failure even when the Project is compiling properly, please use this method

a.      Open Developer Console. [View Menu => Terminal]

b.      Navigate to your projectDirectory inside the Developer Console.Check if the following command works.

YourProject/> dotnet-ef --version 

                                                              i.      If the above command works, then go to step (c), else follow the next step

YourProject/>dotnet tool install --global dotnet-ef  

c.       Now add the following commands one after another. The below command will create a migration file.

YourProject/>dotnet ef migrations add v1  

d.      The next command below will execute the migration file to create the Database and tables.

YourProject/>dotnet ef database update 

12.  Use either Step (10) or (11). No need to follow both. If the above steps are successful, you can verify whether your database is created in the SQL Server Object Explorer. [View => SQL Server Object Explorer]

                                                               i.