I have had some trouble deleting the child in a one-to-many relationship in NHibernate. My schema described a simple parent-child relationship: a parent can have multiple children and every child has exactly one parent.
In the database schema I had two tables parentTable and childTable. ParentTable had an ID column and some other columns. The childTable had an ID primary key column, some other columns and a parentId NOT NULL column which had a foreign key constraint against the ID column in the parentTable.