在Entity Framework代码优先方法中，两个字段的组合必须唯一。会怎么样？

Question

我有两个班级联系人和组

结合FirstName和LastName必须是唯一的，可以为单个联系人添加多个地址。如何在实体框架代码优先方法中做到这一点？

public class Contacts

{

    [Key]

    public int ContactID { get; set; }

    [ForeignKey("Group")]

    public int GroupID { get; set; }

    [Required]

    public string FirstName { get; set; }

    [Required]

    public string LastName { get; set; }

    [Required]

    public string Address { get; set; }

    [Required]

    public string Number { get; set; }

    [Required]

    [EmailAddress]

    public string EmailId { get; set; }

    [DataType(DataType.Date)]

    public DateTime CreateDate { get; set; }

    public DateTime? ModifiedDate { get; set; }

    public virtual Groups Group { get; set; }

}

public class Groups

{

    [Key]

    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]

    public int GroupID { get; set; }

    [Required]

    public string GroupName { get; set; }

    [Required]

    public string GroupDiscription { get; set; }

    public DateTime CreateDate { get; set; }

    public DateTime ModifiedDate { get; set; }

}