Python Peewee ORM：基于外键字段的属性进行选择（反向参考）

我正在尝试根据外键字段中的值进行选择

我的模型是这样的：

class Domain(BaseModel):
domain_check_time = DateTimeField()
domain_name = CharField()
domain_health = BooleanField()
domain_registration_expiry_date = DateField()
domain_registration_expiry_health = BooleanField()
domain_ssl_issuer_cn = CharField()
domain_ssl_expiry_date = DateField()
domain_ssl_expiry_health = BooleanField()
domain_mxtoolbox_health = BooleanField(null = True)

class MXToolboxReport(BaseModel):
    domain = ForeignKeyField(Domain, backref = 'mxtoolbox_reports', null = True)
    command = CharField()
    response = TextField()

class MXToolboxBatch(BaseModel):
    mxtoolbox_batch_time = DateTimeField()
    domain = ForeignKeyField(Domain, backref = 'mxtoolbox_batch', null = True)
    report = ForeignKeyField(MXToolboxReport, backref = 'mxtoolbox_batch', null = True)

我试图基于最近的

mxtoolbox\u batch\u time

的mxtoolbox\u batch\u time属性返回N个域

我试图用for循环来思考这个问题的逻辑，但遇到了麻烦——我还怀疑有一种更优雅的方法

这是我能够得出的近似值（伪代码）：

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与其在域中循环，为什么不发现哪个MXToolboxBatch是最新的（即max（MXToolboxBatch\u batch\u time））。然后根据该结果加入域和MXToolboxBatch。在uber伪代码中：

domains = Domain.select()

newest_batches = MXToolboxBatch.Select.limit(0)

for domain in domains:
    newest_batch = MXToolboxBatch.select().where(MXToolboxBatch.domain == domain).order_by(MXToolboxBatch.id.desc()).get()
    newest_batches += newest_batch

Domain.select().join(newest_batches).order_by(MXToolboxBatch.mxtoolbox_batch_time.desc()).limit(25)

newest_batch_is = MXToolboxBatch.Select(fn.MAX(mxtoolboxbatch_batch_time))

result_is = Domain.Select().join(MXToolboxBatch).where(MXToolboxBatch.batch_time = newest_batch_is).limit(N)