query.py 文件源码

def get_count(self, using):
        """
        Performs a COUNT() query using the current filter constraints.
        """
        obj = self.clone()
        obj.add_annotation(Count('*'), alias='__count', is_summary=True)
        number = obj.get_aggregation(using, ['__count'])['__count']
        if number is None:
            number = 0
        return number