EF Core中的多个相关FK

Question

我有segmentation类，它们有一些价格范围，与office和route相关。我想要与路线和县相关的routeCountyMap表，但每个细分只能分配一次县。 例如。 200-400细分具有 A 和 B 办公室，而 A 办公室具有 E，F，G 路线；如果在 F 路线中有 X 县，则无法进行2 * 00-400细分*。我的代码在下面，如何安排？

public class segment
{
    [Key]
    public Guid segmentId { get; set; }
    public string name { get; set; }
    public Guid organisationId { get; set; }
}

public class office
{
    [Key]
    public Guid officeId { get; set; }
    public string name { get; set; }
    public Guid segmentId { get; set; }
    public segment segment { get; set; }
}

public class route
{
    [Key]
    public Guid routeId { get; set; }
    public string name { get; set; }
    public Guid officeId { get; set; }
    public office office { get; set; }
}

public class county
{
    [Key]
    public Guid countyId { get; set; }
    public string name { get; set; }
    public Guid cityId { get; set; }
}

public class routeCountyMap
{
    public Guid routeCountyMapId { get; set; }
    public Guid routeId { get; set; }
    public Guid countyId { get; set; }
    public route route { get; set; }
    public county county { get; set; }
}

public class user
{
    [Key]
    public Guid userId { get; set; }
    public string name { get; set; }
}

public class routeUserMap
{
    [Key]
    public Guid routeUserMapId { get; set; }
    public Guid routeId { get; set; }
    public Guid userId { get; set; }
    public route route { get; set; }
    public user user { get; set; }
}