class Social(models.Model):
    name = models.CharField(verbose_name="текст ссылки", max_length=64, default=None, null=True)
    link = models.CharField(verbose_name="ссылка", max_length=64, default=None, null=True)

    class Meta:
        verbose_name = "Ссылки на соц. сети"

class AboutMe(SingletonModel):

    content = HTMLField()
    inst = models.OneToOneField(Social, related_name="page", verbose_name="Истаграм", on_delete=models.CASCADE, null=True, default=None)

    class Meta:
        verbose_name = "страница 'Обо мне'"



==============================================
python3 manage.py migrate

  Applying other_page.0002_auto_20210115_2032...Traceback (most recent call last):
  File "manage.py", line 22, in <module>
    main()
  File "manage.py", line 18, in main
    execute_from_command_line(sys.argv)
  File "/home/dmitry/work/ermak/env/lib/python3.6/site-packages/django/core/management/__init__.py", line 401, in execute_from_command_line
    utility.execute()
  File "/home/dmitry/work/ermak/env/lib/python3.6/site-packages/django/core/management/__init__.py", line 395, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/home/dmitry/work/ermak/env/lib/python3.6/site-packages/django/core/management/base.py", line 330, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/home/dmitry/work/ermak/env/lib/python3.6/site-packages/django/core/management/base.py", line 371, in execute
    output = self.handle(*args, **options)
  File "/home/dmitry/work/ermak/env/lib/python3.6/site-packages/django/core/management/base.py", line 85, in wrapped
    res = handle_func(*args, **kwargs)
  File "/home/dmitry/work/ermak/env/lib/python3.6/site-packages/django/core/management/commands/migrate.py", line 245, in handle
    fake_initial=fake_initial,
  File "/home/dmitry/work/ermak/env/lib/python3.6/site-packages/django/db/migrations/executor.py", line 117, in migrate
    state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
  File "/home/dmitry/work/ermak/env/lib/python3.6/site-packages/django/db/migrations/executor.py", line 147, in _migrate_all_forwards
    state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
  File "/home/dmitry/work/ermak/env/lib/python3.6/site-packages/django/db/migrations/executor.py", line 229, in apply_migration
    migration_recorded = True
  File "/home/dmitry/work/ermak/env/lib/python3.6/site-packages/django/db/backends/sqlite3/schema.py", line 35, in __exit__
    self.connection.check_constraints()
  File "/home/dmitry/work/ermak/env/lib/python3.6/site-packages/django/db/backends/sqlite3/base.py", line 348, in check_constraints
    bad_value, referenced_table_name, referenced_column_name
django.db.utils.IntegrityError: The row in table 'other_page_aboutme' with primary key '1' has an invalid foreign key: other_page_aboutme.inst_id contains a value 'inst_id' that does not have a corresponding value in other_page_social.id.