Example C# class showing the basic and recurring patterns of fields used in Code First Entity Framework

Code First Entity Framework Examples.cs

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Data.Entity;
using System.Globalization;
using System.Linq;
using System.Web.Security;

class Example
{
  // Primary Key
  [Key]
  [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
  public int Id { get; set; }
  
  [Display(Name = "Created Date")]
  public DateTime? CreatedDate { get; set; }
  
  // Required Field
  [Required]
  public string Title { get; set; }
  
  // Tweet text
  [MaxLength(140)]
  public string Tweet { get; set; }
  
  // To-Many on Post
  public virtual ICollection<Post> Posts { get; set; }
  
  // To-One on Author
  [ForeignKey("Author")]
  public int AuthorId { get; set; }
  public virtual Author Author { get; set; }
  
  [Display(Name = "E-Mail")]
  [EmailAddress]
  public string Email { get; set; }
  
  [DataType(DataType.MultilineText)]
  public string Body { get; set; }
}

public static class ExampleExtensions
{
  public static Example Create(this DbSet<Example> examples)
  {
    Example ex = new Example();

    ex.CreatedDate = DateTime.Now;

    // Set Fields

    examples.Add(ex);

    return ex;
  }
}