django-查詢對象列表及其對象字段

Question

我想檢查每個Threads中所有Message的MessageState （即order_threads_message ），如果任何一個線程都隱藏了所有消息，則將該線程也隱藏（/或從order_threads_message中刪除）。 我想在將其傳遞給模板之前在視圖中執行此操作。 我怎么做？ 如果您沒有得到我，請詢問。 我很樂意解釋。 請幫助我如何在視圖中執行此操作。 我會很感激。 謝謝。

models.py：

class Thread(models.Model):
    subject = models.CharField(max_length=50, blank=True, null=True)
    user = models.ManyToManyField(User)

class ThreadState(models.Model):
    thread = models.ForeignKey(Thread)
    user = models.ForeignKey(User)
    thread_hidden = models.BooleanField(default=False)

class Message(models.Model):
    thread = models.ForeignKey(Thread)
    sender = models.ForeignKey(User)
    sent_date = models.DateTimeField(default=datetime.now)
    body = models.TextField()

class MessageState(models.Model):
    message = models.ForeignKey(Message)
    user = models.ForeignKey(User)
    read = models.BooleanField(default=False)
    message_hidden = models.BooleanField(default=False)

views.py

@login_required
def message(request):
    user = request.user
    threads = user.thread_set.all()
    order_threads_message = threads.annotate(max_sent_date=Max('message__sent_date')).order_by('-max_sent_date')
    if order_threads_message.count() > 0:
        recent_thread = order_threads_message[0]
        if recent_thread.message_set.all().count() > 0:
            recent_thread_conversations = recent_thread.message_set.all()
            return render(request, 'conversations.html', {
                'all_threads':order_threads_message,
                'conversations':recent_thread_conversations,
                'active': recent_thread.id
                })
        else:
            recent_thread_conversations = 0
            return render(request, 'conversations.html', {
                'all_threads':order_threads_message,
                'conversations':recent_thread_conversations,
                'active': recent_thread.id
                })
    else:
        order_threads_message = 0
        recent_thread_conversations = 0
        return render(request, 'conversations.html', {
            'all_threads':order_threads_message,
            'conversations':recent_thread_conversations,
            })

Answer 1

我已經針對以下模型運行了此查詢：

楷模

class Thread(models.Model):
    subject = models.CharField(max_length=50, blank=True, null=True)
    user = models.ManyToManyField(User)

class ThreadState(models.Model):
    thread = models.ForeignKey(Thread)
    user = models.ForeignKey(User)
    thread_hidden = models.BooleanField(default=False)

class Message(models.Model):
    thread = models.ForeignKey(Thread, related_name = 'message_thread')
    sender = models.ForeignKey(User)
    sent_date = models.DateTimeField(default=datetime.now)
    body = models.TextField()

class MessageState(models.Model):
    message = models.ForeignKey(Message, related_name='messagestate_message')
    user = models.ForeignKey(User)
    read = models.BooleanField(default=False)
    message_hidden = models.BooleanField(default=False)

詢問

Thread.objects.filter(message_thread__in = Message.objects.filter(messagestate_message__in=MessageState.objects.filter(message_hidden=False)))

如果其MessageState的message_hidden至少一個為False則此查詢將返回Thread對象。