System.Data.Entity.ModelConfiguration missing in EF core

.net-core, ef-fluent-api, entity-framework-core

Solution

I've just stumbled across this question as I was searching for the answer myself. I found that it is not (yet?) implemented in EF Core but can be implemented yourself fairly easily.

You can create one of these:

using Microsoft.EntityFrameworkCore.Metadata.Builders;

namespace Microsoft.EntityFrameworkCore
{
    public abstract class EntityTypeConfiguration<TEntity> where TEntity : class
    {
        public abstract void Map(EntityTypeBuilder<TEntity> modelBuilder);
    }

    public static class ModelBuilderExtensions
    {
        public static void AddConfiguration<TEntity>(this ModelBuilder modelBuilder, EntityTypeConfiguration<TEntity> configuration) where TEntity : class
        {
            configuration.Map(modelBuilder.Entity<TEntity>());
        }
    }
}

And then you can create a configuration for the entity itself: -

using Microsoft.EntityFrameworkCore;
using Project.Domain.Models;
using Microsoft.EntityFrameworkCore.Metadata.Builders;

namespace Project.Persistance.EntityConfigurations
{
    public class MyEntityConfiguration : EntityTypeConfiguration<MyEntity>
    {
        public override void Map(EntityTypeBuilder<MyEntity> modelBuilder)
        {
            modelBuilder
                .Property();//config etc
        }
    }
}

You can then load all your configurations somewhere (there's probably both a better way and a better place for doing it... but this is what I did): -

using Microsoft.EntityFrameworkCore;
using Project.Domain.Models;
using Project.Persistance.EntityConfigurations;

namespace Project.Persistance
{
    public class MyDbContext : DbContext
    {
        // Normal DbContext stuff here

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.AddConfiguration(new MyEntityConfiguration());
        }
    }
}

Problem

Original source