title: get person id through authenticated user id
body: <p>I try to get person id of my Person model, connected with User model</p>
  
  <pre><code>from django.db import models
  from django.contrib.auth.models import User
  
  
      class Person(models.Model):
          user = models.ForeignKey(User, blank=False, null=False, on_delete=models.CASCADE)
          middle_name = models.CharField(max_length=30)
  
          def __str__(self):
              return '%s %s %s' % (self.user.last_name, self.user.first_name, self.middle_name)
  </code></pre>
  
  <p>from template-generated page, but I only can get user id who authenticated right now</p>
  
  <pre><code>{{ user.id }}
  </code></pre>
  
  <p>but not Person id.</p>
  
  <p>How can I get Person id through user id on the page?</p>