构造一个连接的 django 查询
我正在与另一个系统上的遗留数据库进行交互，因此模型是一成不变的，不是很 django-ey。
我的 models.py：
class Site(models.Model):
site_code = models.CharField(max_length=30, primary_key=True)
name = models.CharField(unique=True, max_length=300)
class Document(models.Model):
id = models.IntegerField(primary_key=True)
site_ref = models.ForeignKey(Site)
description = models.CharField(max_length=1500)
class DocumentStatusCategory(models.Model):
id = models.IntegerField(primary_key=True)
name = models.CharField(unique=True, max_length=90)
class DocumentStatus(models.Model):
id = models.IntegerField(primary_key=True)
document = models.ForeignKey(Document)
status = models.ForeignKey(DocumentStatusCategory)
changed_by = models.ForeignKey(User)
created_at = models.DateTimeField()
在我的 views.py 中，我想检索包含属于指定 的所有 （例如 Document 对象的查询集站点site_ref=mysite）不具有任何具有 status=4 的相关 DocumentStatus 对象>。
知道如何将其作为单个（非 sql 密集型）行来完成吗？
I'm interacting with a legacy db on another system, so the models are written in stone and not very django-ey.
My models.py:
class Site(models.Model):
site_code = models.CharField(max_length=30, primary_key=True)
name = models.CharField(unique=True, max_length=300)
class Document(models.Model):
id = models.IntegerField(primary_key=True)
site_ref = models.ForeignKey(Site)
description = models.CharField(max_length=1500)
class DocumentStatusCategory(models.Model):
id = models.IntegerField(primary_key=True)
name = models.CharField(unique=True, max_length=90)
class DocumentStatus(models.Model):
id = models.IntegerField(primary_key=True)
document = models.ForeignKey(Document)
status = models.ForeignKey(DocumentStatusCategory)
changed_by = models.ForeignKey(User)
created_at = models.DateTimeField()
In my views.py I want to retrieve a queryset with all the Document objects that belong to a specified Site (say site_ref=mysite) which do not have any related DocumentStatus objects with status=4.
Any idea how I can do this as a single (non-sql intensive) line?
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不完全是一个查询，但我认为如果不使用原始 SQL 就无法实现这一点。我认为两个查询还不错。
我应该提到的是，上面假设 Document 和 DocumentStatus 之间的反向关系是
documentstatus_set。您可以明确地说明反向关系，如下所示：然后查询变为：
Not exactly one query, but I don't think that's achievable without going down to raw sql. Two queries isn't bad though I suppose.
I should mention that the above assumes that the reverse relation between Document and DocumentStatus is
documentstatus_set. You can explicitly state what the reverse relation is like so:Then the query becomes: