StudyFields start

models/courses

@@ -38,6 +38,7 @@ CourseParticipant
     course       CourseId
     user         UserId
     registration UTCTime
+    field        StudyFeaturesId Maybe
     UniqueParticipant user course
 CourseUserNote
     course       CourseId

models/users

@@ -30,6 +30,7 @@ StudyFeatures
     field         StudyTermsId
     type          StudyFieldType
     semester      Int
+    updated       UTCTime default=now -- zuletzt als gültig gesehen
     -- UniqueUserSubject user degree field -- There exists a counterexample
 StudyDegree
     key           Int

src/Foundation.hs

@@ -2018,7 +2018,8 @@ instance YesodAuth UniWorX where
               return str
 
           fs <- either (\err -> throwError . ServerError $ "Could not parse features of study: " <> err) return userStudyFeatures
-
+          -- TODO: just update StudyFeaturesUpdate in case of no-change
+          -- TODO: keep old is referenced in CourseParticipant
           lift $ deleteWhere [StudyFeaturesUser ==. userId]
 
           forM_ fs $ \StudyFeatures{..} -> do