NHibernate Many-to-one cascade

Question

I have the below two classes:

public class Project
{

    public virtual int ProjectId { get; set; }
    public virtual string ProjectName { get; set; }
             


        

Answer 1

The many-to-one cascade does not support all-delete-orphan, see:

• 5.1.10. many-to-one

Also, it would be almost impossible to handle this feature by NHibernate's session. Because it does not have to be clear, that the referenced many-to-one is really orphan. There should be some farther checks in DB... there could be other places referencing this table row...

Suggestion: do it in your code as a part of the DAO or Business Facade implementation. Check if there are really no dependencies, and then issue explicit Delete()

EXTEND: Here is a QueryOver syntax to get a list of all "orphan" LegalEntity

// subquery
var subquery = QueryOver.Of()
    .Select(x => x.LegalEntity.LegalEntId);

// just these legal entities, which are NOT used
var query = session.QueryOver()
    .WithSubquery
      .WhereProperty(y => y.LegalEntId)
      .NotIn(subquery)
    ;

// orphans
var list = query
    .List();