Force trainingitemqualifications to be unique

training/models.py

@@ -74,6 +74,9 @@ class TrainingItemQualification(models.Model):
             if level.user_has_requirements(self.trainee):
                 level_qualification = TrainingLevelQualification.objects.create(trainee=self.trainee, level=level)
 
+    class Meta:
+        unique_together = ["trainee", "item", "depth"]
+
 
 # Levels
 class TrainingLevel(models.Model, RevisionMixin):