title: type object 'StudentPerformance' has no attribute 'objects'
body: <p>Here is my code
  models.py</p>
  
  <pre><code>class StudentPerformance(models.Model):
      student_activity=models.ForeignKey(StudentsActivity,db_index=True)
      student_subactivity=models.ForeignKey(StudentSubactivity,db_index=True)
      student_detail=models.ForeignKey(StudentDetail,db_index=True)
      grade_section=models.ForeignKey(UnitGradeSection,db_index=True)
      date=models.DateField(blank=True,null=True)
      venue=models.CharField(max_length=250,blank=True,null=True)
      remarks=models.CharField(max_length=250,blank=True,null=True)
  </code></pre>
  
  <p>Views.py </p>
  
  <pre><code>class StudentActivity(LoginRequiredMixin,TemplateView):
      template_name="student/student_activity.html"
      form_class2=PerformanceForm
  
      def get_context_data(self,*args,**kwargs):
          context=super(StudentActivity,self).get_context_data(*args,**kwargs)
          context['stud']=StudentDetail.objects.get(id=self.kwargs['stu_id'])
          context['vaccination']=VaccineMaster.objects.all()
          context['activity']=StudentsActivity.objects.all()
          context['subactivity']=StudentSubactivity.objects.all()
          context['form']=self.form_class
          context['form1']=self.form_class1
          context['form2']=self.form_class2
          return context
  
      def post(self,request,*args,**kwargs):
          self.context=super(StudentActivity,self).get_context_data(*args,**kwargs)
  
  
          if 'save' in request.POST:
              stu_ids=request.POST.get('stud_id[]')
              grade_ids=request.POST.get('grade_id[]')
              act=request.POST.get('act') 
              subact=request.POST.get('sub')
              form=self.form_class2(self.request.POST)
              if form.is_valid():
                  date=form['date'].data
                  venue=form['venue'].data
                  remark=form['remarks'].data
                  d=datetime.strptime(date,'%d-%m-%Y')
  
                  perform,created=StudentPerformance.objects.get_or_create(student_activity_id=act,student_subactivity_id=subact,student_detail_id=stu_ids,grade_section_id=grade_ids,date=d,venue=venue,remarks=remark)
                  if created:
                      messages.success(request,'Details Entered Successfully')
                      return HttpResponseRedirect('/student/student_activity/%s' %self.kwargs['stu_id'])
              else:
                  message.error(request,'Nothing To save')
                  return HttpResponseRedirect('')
  </code></pre>
  
  <p>Iam getting an error like "type object 'StudentPerformance' has no attribute 'objects'" and cannot save the data to the database.Please help me to fix this error.Thank You.</p>