Is it possible to set a unique constraint using Entity Framework Code First?

Question

I want to enforce Unique constraint in a table & I am using Entity Framework Code-First.

Is it possible to add a unique constraint using EF 6 as i believe in ear

Answer 1

Use this to define it in config class, if you're avoiding using annotations:

public class YourTableConfig : EntityTypeConfiguration
{
  public YourTableConfig()
  {
    ToTable("YourTableDbName");

    HasKey(u => u.Id);

    Property(c => c.CompanyId).HasColumnType("nvarchar").HasMaxLength(9).IsRequired();

    HasIndex(x => x.CompanyId).IsUnique(); // This sets the unique index
  }
}