Database first approach, Entity Framework Core in .NET 5

Before getting started, I assume you have some knowledge of Entity Framework and .NET Core.

Suppose you have a database and you want to use EF Core.

(If you don’t have, run the Database script and create a sample database.)

Let’s start

Step1: Create a .NET 5 project using Visual Studio. Of course you can use VS Code.

1 — Create Project wizard from Visual Studio 2019

2 — Name your project, 3 — Select the project type and then create

Step2: Install the required packages for Entity Framework, Entity Framework Tooling. Install the below packages using package manger console (PMC):

install-package Microsoft.EntityFrameworkCore.SqlServer

install-package Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore

Install-Package Microsoft.EntityFrameworkCore.Tools

Step 3: In order to generate DbContext file and Entity (which represents the table in our database), we need to run the below command

Scaffold-DbContext “Server=.\SQLExpress;Database=EmployeDB;Trusted_Connection=True;” Microsoft.EntityFrameworkCore.SqlServer -OutputDir Models

In above command server_details (holds the db connection string), db provider and the output folder where we want to generate our entities and DbContext file.

Generated files from scaffold

Step4: Let’s move the connection string to AppSettings.json file and read it from their.

“ConnectionStrings”: {
“DefaultConnection”: “Server=.\SQLExpress;Database=EmployeDB;Trusted_Connection=True;”
}

EF Core does not provide a parameter-less constructor, instead you must pass a parameter of type DbContextOptions. This parameter is usually used to configure some context options such as what type of database connection string is used.

Update the constructor of EFCoreDBFirstContext with DbContext.

Updated EFCoreDBFirstContext File

Note: I have moved the EFCoreDBFirstContext class from Models folder to Context folder

Now add the DbContext service into execution pipeline

public void ConfigureServices(IServiceCollection services)
{
   services.AddDbContext<EFCoreDBFirstContext>(options =>
              options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));
services.AddControllersWithViews();
}

Step5: Add a controller Employee (MVC Controller with views, using Entity Framework) and select the values accordingly.

Add model

Visual studio will do the rest of the work.

Now you can run the application

Feel free to drop a question or feedback in comment section, will be more than happy to respond :)