def date_trunc_sql(self, lookup_type, field_name):
    "\n        Given a lookup_type of 'year', 'month' or 'day', returns the SQL that\n        truncates the given date field field_name to a DATE object with only\n        the given specificity.\n        "
    raise NotImplementedError()
Given a lookup_type of 'year', 'month' or 'day', returns the SQL that
truncates the given date field field_name to a DATE object with only
the given specificity.
def date_trunc_sql(self, lookup_type, field_name):
    "\n        Given a lookup_type of 'year', 'month' or 'day', returns the SQL that\n        truncates the given date field field_name to a DATE object with only\n        the given specificity.\n        "
    raise NotImplementedError()