In EF6 we usually able to use this way to configure the Entity.
public class AccountMap : EntityTypeConfiguration
{
public AccountMap()
In EF7, you override OnModelCreating on the DbContext class you're implementing.
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity()
.ForRelational(builder => builder.Table("Account"))
.Property(value => value.Username).MaxLength(50)
.Property(value => value.Email).MaxLength(255)
.Property(value => value.Name).MaxLength(255);
}