Merge pull request #430 from maheshgudi/multiple_answerpaper

Fix multiple Answerpaper objects returned error

2 files changed, 20 insertions, 10 deletions

diff --git a/yaksh/models.py b/yaksh/models.py
index 9a406c3..93e656a 100644
--- a/yaksh/models.py
+++ b/yaksh/models.py
@@ -1172,7 +1172,7 @@ class QuestionPaper(models.Model):
         return all_questions
 
     def make_answerpaper(self, user, ip, attempt_num, course_id):
-        """Creates an  answer paper for the user to attempt the quiz"""
+        """Creates an answer paper for the user to attempt the quiz"""
         try:
             ans_paper = AnswerPaper.objects.get(user=user,
                                                 attempt_number=attempt_num,
@@ -1197,14 +1197,6 @@ class QuestionPaper(models.Model):
             ans_paper.questions_order = ",".join(question_ids)
             ans_paper.save()
             ans_paper.questions_unanswered.add(*questions)
-        except AnswerPaper.MultipleObjectsReturned:
-            ans_paper = AnswerPaper.objects.get(user=user,
-                                                attempt_number=attempt_num,
-                                                question_paper=self,
-                                                course_id=course_id
-                                                ).order_by('-id')
-            ans_paper = ans_paper[0]
-
         return ans_paper
 
     def _is_attempt_allowed(self, user, course_id):
@@ -1514,6 +1506,11 @@ class AnswerPaper(models.Model):
 
     objects = AnswerPaperManager()
 
+    class Meta:
+        unique_together = ('user', 'question_paper',
+                           'attempt_number', "course"
+                           )
+
     def get_per_question_score(self, question_id):
         if question_id not in self.get_questions().values_list('id', flat=True):
             return 'NA'
diff --git a/yaksh/test_models.py b/yaksh/test_models.py
index df8372c..2aa55d4 100644
--- a/yaksh/test_models.py
+++ b/yaksh/test_models.py
@@ -12,6 +12,7 @@ from datetime import datetime, timedelta
 from django.utils import timezone
 import pytz
 from django.contrib.auth.models import Group
+from django.db import IntegrityError
 from django.core.files import File
 from django.forms.models import model_to_dict
 from textwrap import dedent
@@ -835,7 +836,8 @@ class AnswerPaperTestCases(unittest.TestCase):
             question_paper=self.question_paper,
             start_time=self.start_time,
             end_time=self.end_time,
-            user_ip=self.ip
+            user_ip=self.ip,
+            course=self.course
         )
         self.attempted_papers = AnswerPaper.objects.filter(
             question_paper=self.question_paper,
@@ -1375,6 +1377,17 @@ class AnswerPaperTestCases(unittest.TestCase):
         self.assertEqual(self.user2_answerpaper2.current_question(),
                          self.question1)
 
+    def test_duplicate_attempt_answerpaper(self):
+        with self.assertRaises(IntegrityError):
+            new_answerpaper = AnswerPaper.objects.create(
+                user=self.answerpaper.user,
+                question_paper=self.answerpaper.question_paper,
+                attempt_number=self.answerpaper.attempt_number,
+                start_time=self.answerpaper.start_time,
+                end_time=self.answerpaper.end_time,
+                course=self.answerpaper.course
+                )
+
 
 ###############################################################################
 class CourseTestCases(unittest.TestCase):