C#: Entity Framework - Code First, no Database - (Console Application)

Program.cs

Example C# 2018

using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace CodeFirst
{
    class Program
    {
        static void Main(string[] args)
        {
            using (var db = new StudentContext())
            {
                var student = new Student() { Name = "Antonio" };
                var subject1 = new Subject() { Name = "Subject 1" };
                var subject2 = new Subject() { Name = "Subject 2" };

                student.SubjectsList.Add(subject1);
                student.SubjectsList.Add(subject2);

                db.Students.Add(student);
                db.SaveChanges();
            }
        }
    }

    public class Student
    {
        public Student()
        {
            this.SubjectsList = new List<Subject>();
        }

        public int StudentID { get; set; }
        public string Name { get; set; }
        public virtual List<Subject> SubjectsList { set; get; }

    }
    public class Subject
    {
        public int SubjectID { get; set; }
        public string Name { get; set; }
        public virtual Student Student { get; set; }
    }
    class StudentContext : DbContext
    {
        public DbSet<Student> Students { set; get; }
        public DbSet<Subject> Subjects { set; get; }
    }
}

App.config

Example C# 2018

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
  </configSections>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.2" />
  </startup>
  <entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework" />
    <providers>
      <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
    </providers>
  </entityFramework>
  <connectionStrings>
      <add name="StudentContext" connectionString="Server=ANTONIO-PC\SQLEXPRESS; Database=StudentDatabase; User=sa; Password=1234567" providerName="System.Data.SqlClient"/>
  </connectionStrings>
</configuration>

Output

Thêm Birthday vào bảng Student

Tool > Nuget Package Manager > Package Manage Console
// Chạy lệnh này tại cửa sổ Console
Enable-Migrations
Add-Migration AddBirthday
Update-Database

Output

Xóa Birthday trên bảng Student

Add-Migration RemoveBirthday
Update-Database

Output