handle deleting properly - e.g. if had a refimg that was used for a match earlier then deal with it, and when deleting a person, dont leave behind orphaned refimgs

person.py

@@ -134,9 +134,12 @@ def person(id):
             person = Person.query.get(id)
             if 'delete' in request.form:
                 st.SetMessage("Successfully deleted Person: ({})".format( person.tag ) )
-                # do the linkage tables by hand
+                # do linkages by hand, or one day replace with delete cascade in the DB defintions
                 db.session.execute( f"delete from face_refimg_link frl where refimg_id in ( select refimg_id from person_refimg_link where person_id = {id} )" )
                 db.session.execute( f"delete from person_refimg_link where person_id = {id}" )
+                db.session.execute( f"delete from refimg where id not in ( select refimg_id from person_refimg_link )" )
+
+                # now can delete the person entry with no foreign key data left
                 Person.query.filter(Person.id==id).delete()
                 db.session.commit()
                 return redirect( url_for( 'persons' ) )
@@ -148,6 +151,8 @@ def person(id):
                 if new_refs != person.refimg:
                     deld = list(set(person.refimg) - set(new_refs));
                     person.refimg = new_refs
+                    # delete the "match" between a face found in a file and this ref img
+                    FaceRefimgLink.query.filter(FaceRefimgLink.refimg_id==deld[0].id).delete()
                     Refimg.query.filter(Refimg.id==deld[0].id).delete()
                     st.SetMessage( f"Successfully Updated Person: removed reference image {deld[0].fname}" )
                 else: