title: Model Setup with second normal form for ManyToManyFields
body: <p>I'm new to databases and new to Django. I need your help. </p>
  
  <p>I want to have for example a database with Persons having e.g. different shirts. Shirts have different lengths.</p>
  
  <p>For example Peter has three shirts. A red T-shirt, a blue longsleeve shirt and a blue t-shirt.</p>
  
  <p>Marcus has also has a red shirt, but it should only have long sleeves.</p>
  
  <p>How do I create a model, where the second normalized Foreign- or ManyToManyField can have different values, depending on the top level (Person) data?</p>
  
  <p>Or do I need to have each shirt as a different entry (blue long, blue short etc.) and relate this to the person?</p>
  
  <p>Django usually creates an additional table with an ID the ID of the Person and the ID of the shirt.
  Is there a way to add a third row for the sleeves then?</p>
  
  <p>My Django Model is something like this:</p>
  
  <pre><code>Class Length(models.Model):
      name_length = models.CharField(max_length=10) # e.g. short, long, half
  
  Class Shirt(models.Model):
      name_shirt = models.CharField(max_length=20) # e.g. red-one, blue-one
      shirt_length = models.ManyToManyField(Length)
  
  Class Person(models.Model):
      name = models.CharField(max_length=20)
      persons_shirt = models.ManyToManyField(Shirt)
  </code></pre>
  
  <p>Thank you</p>