C# Class Project

Employees Register

This project will list, create, update and delete an employee.

Commands used to create the project:

• mkdir c-sharp-class-project
• cd c-sharp-class-project
• git init
• include the .gitignore, .gitattributes and the README.md files
• git config user.name "My User Name"
• git config user.email [email protected]
• git config --list
• mkdir src
• cd src
• mkdir CSharpClassProject
• cd CSharpClassProject
• dotnet new sln
• mkdir CSharpClassProject.EmployeesRegister
• cd CSharpClassProject.EmployeesRegister
• dotnet new console
• cd ..
• dotnet sln add .\CSharpClassProject.EmployeesRegister\CSharpClassProject.EmployeesRegister.csproj
• cd ..
• cd ..
• git add .
• git status
• git commit -m "Initial commit."
• git log
• git remote add origin <your repository url>
• git push -u origin master

EF CORE

To install the Entity Framework Core, open the project folder in the terminal and run the command below:

dotnet add package Microsoft.EntityFrameworkCore.SqlServer

To execute the dotnet ef command, install the package below:

dotnet add package Microsoft.EntityFrameworkCore.Design
dotnet add package Microsoft.EntityFrameworkCore.Tools
dotnet tool install --global dotnet-ef --version 2.2.6

Create the Employee abstract class inside the Classes\Entities folder:

namespace CSharpClassProject.EfCore.Classes.Entities
{
    public abstract class Employee
    {
        public int Id { get; set; }

        public string Name { get; set; }

        public string CompanyName { get; set; }
    }
}

Create the Developer class inheriting from the Employee class inside the Classes\Entities folder:

namespace CSharpClassProject.EfCore.Classes.Entities
{
    public class Developer : Employee
    {
        
    }
}

Create the IContext interface in the Interfaces folder:

using CSharpClassProject.EfCore.Classes.Entities;
using Microsoft.EntityFrameworkCore;

namespace CSharpClassProject.EfCore.Interfaces
{
    public interface IContext
    {
        DbSet<Developer> Developers { get; set; }
    }
}

Then in the Classes\Entities folder, create the Context class inheriting from the DbContext class, responsible to the database context, and implements the IContext interface created above:

using CSharpClassProject.EfCore.Interfaces;
using Microsoft.EntityFrameworkCore;

namespace CSharpClassProject.EfCore.Classes.Entities
{
    public class Context : DbContext, IContext
    {
        public DbSet<Developer> Developers { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            // Configures the database connection string
            optionsBuilder.UseSqlServer("<connection string>");
        }
    }
}

Now, build the project and then create the initial migration:

dotnet ef migrations add InitialMigration

A Migration folder will be created with tree files (the 20200523165930 is the time when you ran the dotnet ef migrations command):

• 20200523165930_InitialMigration.cs: contains the migrations code to be executed in the database
• 20200523165930_InitialMigration.Designer.cs: contains the migration id and detail code to be executed in the database
• ContextModelSnapshot.cs: contains the entire database snapshot

Then, run the command below to update the database:

dotnet ef database update

To see the entire command that will be executed in the update, add the --verbose parameter:

dotnet ef database update --verbose

To revert some change, execute the comand below:

dotnet ef database update <migration name>

References:

https://docs.microsoft.com/en-us/ef/core/get-started/install/
https://docs.microsoft.com/en-us/ef/core/miscellaneous/connection-strings
https://docs.microsoft.com/en-us/ef/core/miscellaneous/cli/dotnet