Control PhoneNumber Via SQL

Hi,

Sorry for asking question again.

I would like to know if it is possible to control the phone number in SQL
before inserting it to the destination DB?

I have a model in Django:

class BasePerson(TimeStampedModel):
phone_number = PhoneNumberField(max_length=50, verbose_name=_(u'phone
number'), blank=True)

The data for phone number that I am migrating doesn't have country code. I
want to determine first if the number has country code in it, if it doesn't
then I will add the country code on the number before INSERTING it to the
destination database.

Any suggestion will be highly appreciated.

Thanks,
J