title: Foreignkey issue, Key (status_id)=(1) already exists
body: <p>I'm working on a small project ( Kanban Board ) using Django / Rest Framework, I have two models</p>
  <p>Status(columns)  and Task model,</p>
  <p>A task can be only in one column since we drag the task from column to column, which means a task can be only in one column.</p>
  <p>I did an OneToMany relationship by making a Foreign key, but I'm not sure if it's the correct choice because I'm getting an error when I try to add a new task.</p>
  <p>The Error i get :</p>
  <pre><code>duplicate key value violates unique constraint &quot;task_task_status_id_de4e8cac_uniq&quot;
  DETAIL:  Key (status_id)=(1) already exists.
  </code></pre>
  <p>What kind of relationship must I do between the two models?</p>
  <p>This is my models :</p>
  <pre><code>class Task(models.Model):
      status = models.ForeignKey(Status, related_name=&quot;tasks&quot;,  on_delete=models.CASCADE)
      title = models.CharField(max_length=60, blank=False, null=False)
  
  class Status(models.Model):
      title = models.CharField(blank=False, null=False, max_length=255)
      slug = models.CharField(blank=False, null=False, max_length=255)
      order = models.SmallIntegerField(default=0)
  
      def __str__(self):
          return self.title
  </code></pre>
  <p>View :</p>
  <pre><code>def create(self, request):
          formSerializer = self.serializer_class(data = request.data, many= True)
          if formSerializer.is_valid():
              formSerializer.save()
              listSerializer = self.serializer_class(self.queryset, many = True)
              return Response(listSerializer.data, status = status.HTTP_201_CREATED)
          return Response(formSerializer.errors, status.HTTP_400_BAD_REQUEST)
  </code></pre>