EF Core 2.0 Enums stored as string

Question

I was able to store an enum as a string in the database.

builder.Entity(eb =>
{
    eb.Property(b => b.Stage).HasColumnType(\"varchar(20         


        

Answer 1

This is the same question as answered at: Does EF7 support enums?

Answer 2

You can use this to convert all the Enum of all the properties of all the entities into a string and vice versa :

using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
using System;

namespace MyApp
{
    public class DatabaseContext : DbContext
    {
        public DbSet<UserContext> Users { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            // Configure your model here
        }

        protected override void OnModelCreating(ModelBuilder model)
        {
            foreach (var entityType in model.Model.GetEntityTypes())
            {
                foreach (var property in entityType.GetProperties())
                {
                    if (property.ClrType.BaseType == typeof(Enum))
                    {
                        var type = typeof(EnumToStringConverter<>).MakeGenericType(property.ClrType);
                        var converter = Activator.CreateInstance(type, new ConverterMappingHints()) as ValueConverter;

                        property.SetValueConverter(converter);
                    }
                }
            }
        }
    }
}

Answer 3

Value Conversions feature is new in EF Core 2.1.

Value converters allow property values to be converted when reading from or writing to the database. This conversion can be from one value to another of the same type (for example, encrypting strings) or from a value of one type to a value of another type (for example, converting enum values to and from strings in the database.)

public class Rider
{
    public int Id { get; set; }
    public EquineBeast Mount { get; set; }
}

public enum EquineBeast
{
    Donkey,
    Mule,
    Horse,
    Unicorn
}

You can use own conversion

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder
        .Entity<Rider>()
        .Property(e => e.Mount)
        .HasConversion(
            v => v.ToString(),
            v => (EquineBeast)Enum.Parse(typeof(EquineBeast), v));
}

or Built-in converter

var converter = new EnumToStringConverter<EquineBeast>();

modelBuilder
    .Entity<Rider>()
    .Property(e => e.Mount)
    .HasConversion(converter);