Map string column in Entity Framework to Enum

Question

Is there a way to map a string column to an enum in an Entity Model?

I have done this in Hibernate, but can\'t figure it out in EMF.

Answer 1

I had the same problem. I've come up with a solution, but I'm not completely happy with it.

My Person class has a Gender enum, and I use data annotations to map the string to the database and ignore the enum.

public class Person
{
    public int PersonID { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }

    [Column("Gender")]
    public string GenderString
    {
        get { return Gender.ToString(); }
        private set { Gender = EnumExtensions.ParseEnum<Gender>(value); }
    }

    [NotMapped]
    public Gender Gender { get; set; }
}

here is the extension method to get the correct enum from the string.

public class EnumExtensions
{
    public static T ParseEnum<T>(string value)
    {
        return (T)Enum.Parse(typeof(T), value, true);
    }
}

I wrote a blog post about this - http://nodogmablog.bryanhogan.net/2014/11/saving-enums-as-strings-with-entity-framework/

Answer 2

You can do either:

Decorate the Enum property in your class as a text column

[Column(TypeName = "nvarchar(50)")]
public FileTypes FileType { get; set; }

OR

in your DatabaseContext class, override the OnModelCreating and add:

modelBuilder
  .Entity<File>()
  .Property(e => e.FileType)
  .HasConversion(new EnumToStringConverter<FileTypes>());