我想写django queryset，它相当于下面的查询，在db中只命中一次。现在我正在使用 manager.raw() 执行。
与 annotate ，我可以生成内部查询。但是我不能在过滤条件下使用它（当我检查时） queryset.query ，看起来像ex1）。

select *
from table1
where (company_id, year) in (select company_id, max(year) year
                             from table1
                             where company_id=3
                             and total_employees is not null
                             group by company_id);

例1：

SELECT `table1`.`company_id`, `table1`.`total_employees`
FROM `table1`
WHERE `table1`.`id` = (SELECT U0.`company_id` AS Col1, MAX(U0.`year`) AS `year`
                       FROM `table1` U0
                       WHERE NOT (U0.`total_employees` IS NULL)
                       GROUP BY U0.`company_id`
                       ORDER BY NULL)

型号：

class Table1(models.Model):
    year = models.IntegerField(null=False, validators=[validate_not_null])
    total_employees = models.FloatField(null=True, blank=True)
    company = models.ForeignKey('Company', on_delete=models.CASCADE, related_name='dummy_relation')
    last_modified = models.DateTimeField(auto_now=True)
    updated_by = models.CharField(max_length=100, null=False, default="research")

    class Meta:
        unique_together = ('company', 'year',)

我很感激你的回答。