Flunet Nhibernate all-delete-orphan not working like expected

问题

I have following domain classes:

public class News: EntityBase
    {
        public virtual DateTime CreationDate { get; set; }
        public virtual IList<DomainNameToNews> DomainNameToNews { get; set; } 

        public News()
        {
            DomainNameToNews=new List<DomainNameToNews>();           
        }
    }

public class DomainNameToNews : EntityBase
    {
        public virtual DomainName DomainName { get; set; }
        public virtual News News { get; set; }
    }

Mapping:

public class NewsMap : ClassMap<News>
    {
        public NewsMap()
        {
            Id(x => x.Id).GeneratedBy.Identity();
            Map(x => x.CreationDate).Not.Nullable();
            HasMany(x => x.DomainNameToNews).Cascade.AllDeleteOrphan();
        }
    }
 public class DomainNameToNewsMap : ClassMap<DomainNameToNews>
    {
        public DomainNameToNewsMap()
        {
            Id(x => x.Id).GeneratedBy.Identity();
            References(x => x.News).UniqueKey("UQ_DOMAIN_NEWS").Cascade.Delete();
            References(x => x.DomainName).UniqueKey("UQ_DOMAIN_NEWS");
        }
    }

Explanation:

News can be used in different domains so DomainNameToNews is relationship between them. One news can be used by multiple domains.

Problem: What I want is to delete and add DomainToNews objects through News repository.

On update of News Object this object will have a list of DomainNameToNews so When I will update News the row from DomainNameToNews that will not be in this list I want to delete at all from database .Now the row that is not in this List will have Null News ,but I want to delete at all. How I must to map my object to achieve this? If I didn't explain myself enough clear please ask more details. Thnaks!!

回答1:

You need to specify 'inverse' at the one-to-many collection association.

public class NewsMap : ClassMap<News>
    {
        public NewsMap()
        {
            Id(x => x.Id).GeneratedBy.Identity();
            Map(x => x.CreationDate).Not.Nullable();
            HasMany(x => x.DomainNameToNews).Inverse.Cascade.AllDeleteOrphan();
        }
    }
 public class DomainNameToNewsMap : ClassMap<DomainNameToNews>
    {
        public DomainNameToNewsMap()
        {
            Id(x => x.Id).GeneratedBy.Identity();
            References(x => x.News).UniqueKey("UQ_DOMAIN_NEWS");
            References(x => x.DomainName).UniqueKey("UQ_DOMAIN_NEWS");
        }
    }

Explanation on 'inverse' in this blog post

来源：https://stackoverflow.com/questions/22380027/flunet-nhibernate-all-delete-orphan-not-working-like-expected