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我有以下模型（简化），其中警告模型是通用外键，可以包括 Occasion 对象（但也包括其他类型）

Occasion(models.Model):
    start_date = models.DateField()


Warnings(models.Model):
    status = models.CharField()
    content_type = models.ForeignKey(ContentType)
    object_id = models.PositiveIntegerField()
    content_object = generic.GenericForeignKey('content_type', 'object_id')

我想检索任何没有任何警告的场合，但也排除任何在警告表中具有 status='new' 的场合。我应该如何编写这个查询？

编辑：这是得到正确结果的 SQL

select * from occasion left join warnings 
on occasion.id = warnings.object_id 
and warnings.content_type_id = 13 --type id for the model.
and warnings.status <> 'new';

再次编辑：

这就是我解决它的方法：

#First get any occasions with status='new' from warnings
ctype = ContentType.objects.get(app_name="myapp", model="ocassion")

warnings = warning.objects.filter(content_type=ctype, status='new')

#Filter out only object_ids
warning_occasion_list = set(list(warnings.values_list('object_id', flat=True))

#Then exclude these from the occasion query
occasions = occasion.objects.all().exclude(occasion_id__in=warning_occasion_list)
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