remove db.session.execute and use simple ORM statements - less efficient, but only really deleting a small amount anyway

person.py

@@ -3,7 +3,7 @@ from flask_wtf import FlaskForm
 from flask import request, render_template, redirect, url_for, make_response, jsonify
 from main import db, app, ma
 from settings import Settings, AIModel
-from sqlalchemy import Sequence
+from sqlalchemy import Sequence, func
 from sqlalchemy.exc import SQLAlchemyError
 from flask_login import login_required, current_user
 from werkzeug.utils import secure_filename
@@ -143,15 +143,14 @@ def TempRefimgFile( data, tag ):
 @login_required
 def persons():
     persons = Person.query.order_by(Person.tag).all()
-    # get the num matches for each person too, and allow link for it
-    stats = list( db.session.execute( "select p.tag, count(f.id) from person p, face f, face_file_link ffl, face_refimg_link frl, person_refimg_link prl where p.id = prl.person_id and prl.refimg_id = frl.refimg_id and frl.face_id = ffl.face_id and ffl.face_id = f.id group by p.tag" ) )
     for p in persons:
         if not p.refimg:
             continue
-        for s in stats:
-            if p.tag == s[0]:
-                p.num_matches = s[1];
-                break
+        # okay see how many faces match this person
+        stat=Person.query.filter(Person.id==p.id).join(PersonRefimgLink).join(Refimg).join(FaceRefimgLink).with_entities( func.count( Person.tag ) ).group_by( Person.tag ).first()
+        if stat:
+            p.num_matches=stat[0]
+
     return render_template("persons.html", persons=persons)
  
 
@@ -201,10 +200,13 @@ def person(id):
             person = Person.query.get(id)
             if 'delete' in request.form:
                 SetFELog( f"Successfully deleted Person: ({person.tag})" )
-                # 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 )" )
+
+                # delete refimgs that are associated with this person (one-by-one), not super efficient
+                # but simple/clearer than cascades for now
+                for ref in person.refimg:
+                    FaceRefimgLink.query.filter(FaceRefimgLink.refimg_id==ref.id).delete()
+                    PersonRefimgLink.query.filter(PersonRefimgLink.refimg_id==ref.id).delete()
+                    Refimg.query.filter(Refimg.id==ref.id).delete()
 
                 # now can delete the person entry with no foreign key data left
                 Person.query.filter(Person.id==id).delete()