How to create a table corresponding to enum in EF6 Code First?

Question

I\'ve followed MSDN on how to handle enumerations in Code First for EF6. It worked, as supposed to but the field in the created table that refers to the enu

Answer 1

Alberto Monteiro answered this very well. I had to make a few adjustments to get it to work with EF core.

Rename your enum and add description decorators

public enum FacultyEnum 
{
    [Description("English Professor")]
    Eng, 
    [Description("Math Professor")]
    Math, 
    [Description("Economics Professor")]
    Eco 
}

Create a class that represent the table

public class Faculty
{
    private Faculty(FacultyEnum @enum)
    {
        Id = (int)@enum;
        Name = @enum.ToString();
        Description = @enum.GetEnumDescription();
    }

    protected Faculty() { } //For EF

    [Key, DatabaseGenerated(DatabaseGeneratedOption.None)]
    public int Id { get; set; }

    [Required, MaxLength(100)]
    public string Name { get; set; }

    [MaxLength(100)]
    public string Description { get; set; }

    public static implicit operator Faculty(FacultyEnum @enum) => new Faculty(@enum);

    public static implicit operator FacultyEnum(Faculty faculty) => (FacultyEnum)faculty.Id;
}

Your model reference the class

public class ExampleClass
{
    public virtual Faculty Faculty { get; set; }
}

Create a extension method to get description from enum and seed values

using System;
using System.ComponentModel;
using System.Data.Entity;
using System.Data.Entity.Migrations;
using System.Linq;

public static class Extensions
{
    public static string GetEnumDescription<TEnum>(this TEnum item)
        => item.GetType()
               .GetField(item.ToString())
               .GetCustomAttributes(typeof(DescriptionAttribute), false)
               .Cast<DescriptionAttribute>()
               .FirstOrDefault()?.Description ?? string.Empty;
}

Add the seed in YourDbContext.cs

protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Faculty>().HasData(FacultyEnum.Eng, FacultyEnum.Math, FacultyEnum.Eco);
    }

Add the enum table in your DbContext

public class MyClass : DbContext
{
    public DbSet<ExampleClass> Examples { get; set; }
    public DbSet<Faculty> Facultys { get; set; }
}

Use it

var example = new ExampleClass();
example.Faculty = FacultyEnum.Eng;

if (example.Faculty == FacultyEnum.Math)
{
    //code
}

To remember

If you don't add virtual in Faculty property, you must use Include method from DbSet to do Eager Load

var exampleFromDb = dbContext.Examples.Include(x => x.Faculty).SingleOrDefault(e => e.Id == 1);
if (example.Faculty == FacultyEnum.Math)
{
    //code
}

If Faculty property is virtual, then just use it

var exampleFromDb = dbContext.Examples.Find(1);
if (example.Faculty == FacultyEnum.Math)
{
    //code
}

Answer 2

I might be a bit late for the party but I didn't find the answer I was looking for here.

While looking around in the EntityFramework documentation I found the solution, it is the first example in Value Conversions

With this you can make a nice extension method if you want. i.e.

public static void HasEnum<TEntity, TProperty>(this EntityTypeBuilder<TEntity> entityBuilder, Expression<Func<TEntity, TProperty>> propertyExpression)
        where TEntity : class
        where TProperty : Enum
    {
        entityBuilder.Property(propertyExpression)
            .HasConversion(
                v => v.ToString(),
                v => (TProperty)Enum.Parse(typeof(TProperty), v)
            );
    }

Then use it in your OnModelCreating:

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<YourEntity>()
        .HasEnum(e => e.YourProperty);
}