title: Django - Inline (has no ForeignKey to)
body: <p>I'm trying to implement <code>InlineModels</code> but I'm getting error message. Will you please help me? Thank you .</p>
  
  <h1>myproject.api.models</h1>
  
  <pre><code>from django.db import models
  from django.contrib.auth.models import User
  from myproject.song.models import Album, Song, Artist
  
  class UserLibrary(models.Model):
      user = models.ForeignKey(User)
  </code></pre>
  
  <h1>myproject.api.admin.py</h1>
  
  <pre><code>from django.contrib import admin
  from myproject.song.models import Song, Album, Artist, Music
  from myproject.api.models import UserLibrary
  
  class SongInline(admin.TabularInline):
      model = Song
  class UserLibraryAdmin(admin.ModelAdmin):
      search_fields = ['user']
      inlines = [
          SongInline,
          ]
  admin.site.register(UserLibrary, UserLibraryAdmin)
  </code></pre>
  
  <p>Here is my traceback:</p>
  
  <pre><code> Exception at /admin/api/userlibrary/add/
  &lt;class 'myproject.song.models.Song'&gt; has no ForeignKey to &lt;class 'api.models.UserLibrary'&gt;
  </code></pre>