lookups.py 文件源码

def process_lhs(self, compiler, connection, lhs=None):
        from django.db.models import DateTimeField
        lhs, params = super(DateLookup, self).process_lhs(compiler, connection, lhs)
        if isinstance(self.lhs.output_field, DateTimeField):
            tzname = timezone.get_current_timezone_name() if settings.USE_TZ else None
            sql, tz_params = connection.ops.datetime_extract_sql(self.extract_type, lhs, tzname)
            return connection.ops.lookup_cast(self.lookup_name) % sql, tz_params
        else:
            return connection.ops.date_extract_sql(self.lookup_name, lhs), []