System.Data.Entity.ModelConfiguration missing in EF core - entity-framework-core

Question

Trying to load all the configurations dynamically on OnModelCreating for Entity framework core.
what is the other way around if ModelConfiguration is missing.

Answer 1

It's even easier in Core 2.0 now
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata.Builders;
namespace MyApp.DAL.EntityConfigurations
{
public class StudentConfiguration : IEntityTypeConfiguration<Student>
{
public void Configure(EntityTypeBuilder<Student> modelBuilder)
{
modelBuilder.Property(f => f.Name).IsRequired();
}
}
}
Then in your db context:
public DbSet<Student> Students{ get; set; }
public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options) : base(options) { }
protected override void OnModelCreating(ModelBuilder builder)
{
base.OnModelCreating(builder);
// Customizations must go after base.OnModelCreating(builder)
builder.ApplyConfiguration(new StudentConfig());
builder.ApplyConfiguration(new SomeOtherConfig());
// etc.
// etc..
}

Answer 2

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());
}
}
}