title: ManyToMany models relationship Django
body: <p>I have two models:</p>
  
  <pre><code>class University(models.Model):
      name = models.CharField(max_length=50)
      address = models.CharField(max_length=50, null=True, blank=True)
      city = models.CharField(max_length=30, null=True, blank=True)
      country = CountryField(null=True, blank=True)
      created_at = models.DateTimeField(auto_now_add=True)
      modified_at = models.DateTimeField(auto_now=True)
      departments = models.ManyToManyField(Department)
  
  
  class Department(models.Model):
      name = models.CharField(max_length=50)
      address = models.CharField(max_length=50, null=True, blank=True)
      created_at = models.DateTimeField(auto_now_add=True)
      modified_at = models.DateTimeField(auto_now=True)
  </code></pre>
  
  <p>I want to <code>University</code> have many <code>Departments</code> and vice versa which works fine.
  But I also want to store more departments individually for one university.</p>
  
  <p>For instance:</p>
  
  <p>University1 has Department1 and Department2.</p>
  
  <p>University2 has Department1.</p>
  
  <p>I want those departments store individually for each university. Now when I update Department1, ofcourse every University which has that school will see changes. I don't want that. I want to update Department1 but only for the University1 record. Department1 in University2 shouldn't be updated.</p>
  
  <p>I assume that adding <code>through</code> option with intermediate <code>model</code> wouldn't help. What's the best solution?</p>