EF Core - Structure your mapping configurations

I typically use the Fluent API to configure my Entity Framework (Core) model. I think it gives me the most control without polluting my domain model with EF Core specific attributes.

You can do this directly inside the OnModelCreating method inside your DbContext but this can get out-of-control quite fast if you have a lot of objects to be mapped.

	class MyContext : DbContext
	{
	public DbSet<Blog> Blogs { get; set; }
	protected override void OnModelCreating(ModelBuilder modelBuilder)
	{
	modelBuilder.Entity<Blog>()
	.Property(b => b.Url)
	.IsRequired();
	}
	}

view raw MyContext.cs hosted with ❤ by GitHub

A better alternative is to use the IEntityTypeConfiguration<> interface together with the ApplyConfiguration method:

	public class BlogConfiguration : IEntityTypeConfiguration<Blog>
	{
	public void Configure(EntityTypeBuilder<Blog> builder)
	{
	builder.Entity<Blog>()
	.Property(b => b.Url)
	.IsRequired();
	}
	}

view raw BlogConfiguration.cs hosted with ❤ by GitHub

	class MyContext : DbContext
	{
	public DbSet<Blog> Blogs { get; set; }
	protected override void OnModelCreating(ModelBuilder modelBuilder)
	{
	modelBuilder.ApplyConfiguration(new BlogConfiguration());
	}
	}

view raw MyContextFixed.cs hosted with ❤ by GitHub