django1/django/contrib/sites/management.py

"""
Creates the default Site object.
"""

from django.db.models import signals
from django.db import connections
from django.db import router
from django.contrib.sites.models import Site
from django.contrib.sites import models as site_app
from django.core.management.color import no_style


def create_default_site(app, created_models, verbosity, db, **kwargs):
    # Only create the default sites in databases where Django created the table
    if Site in created_models and router.allow_migrate(db, Site):
        # The default settings set SITE_ID = 1, and some tests in Django's test
        # suite rely on this value. However, if database sequences are reused
        # (e.g. in the test suite after flush/syncdb), it isn't guaranteed that
        # the next id will be 1, so we coerce it. See #15573 and #16353. This
        # can also crop up outside of tests - see #15346.
        if verbosity >= 2:
            print("Creating example.com Site object")
        Site(pk=1, domain="example.com", name="example.com").save(using=db)

        # We set an explicit pk instead of relying on auto-incrementation,
        # so we need to reset the database sequence. See #17415.
        sequence_sql = connections[db].ops.sequence_reset_sql(no_style(), [Site])
        if sequence_sql:
            if verbosity >= 2:
                print("Resetting sequence")
            cursor = connections[db].cursor()
            for command in sequence_sql:
                cursor.execute(command)

    Site.objects.clear_cache()

signals.post_migrate.connect(create_default_site, sender=site_app)