我已经盯着这一个有一段时间了，需要一些帮助。
我试图在登录用户已预订会话的日子显示“退出”按钮而不是“预订”按钮。有人能在这里提供一些指导吗？

型号

class Member(models.Model):
    gym = models.ForeignKey(Gym, on_delete=models.CASCADE, blank=True, null=True, related_name="gym_membership")
    member = models.ForeignKey(User, on_delete=models.CASCADE, blank=True, null=True, related_name="member_of_gym")

    def __str__(self):
        return f'{self.member.username}'

class Session(models.Model):
    program = models.ForeignKey(Program, on_delete=models.CASCADE, blank=True, null=True, related_name="session_program")
    focus = models.ForeignKey(Focus, on_delete=models.CASCADE, blank=True, null=True, related_name="session_focus")
    location = models.ForeignKey(Location, on_delete=models.CASCADE, blank=True, null=True, related_name="session_location")
    booking_counter = models.IntegerField(default=0)
    start_datetime: datetime = models.DateTimeField()
    duration = models.DurationField()
    day = models.CharField(max_length=12, blank=True, null=True)
    week_number = models.IntegerField(blank=True, null=True)

    def __str__(self):
        return f'{self.program}, {self.day} - Week {self.week_number}'

class Booking(models.Model):
    member = models.ForeignKey(Member, on_delete=models.CASCADE, blank=True, null=True, related_name="member_booking")
    session = models.ForeignKey(Session, on_delete=models.CASCADE, blank=True, null=True, related_name="booking_session")
    booking = models.BooleanField()
    date_booked = models.DateTimeField()
    date_cancelled = models.DateTimeField(blank=True, null=True)
    attendance_verified = models.BooleanField(blank=True, null=True)

    def __str__(self):
        return f'{self.member.member.username} booked {self.session}'

字符串

次查看

def index(request):
    # store the user information in a variable
    user = request.user
    # get the membership object for that user
    member = Member.objects.get(member=user.id)
    context = {
        "sessions": Session.objects.all(),
        "bookings": Booking.objects.filter(member=member)
    }
    return render(request, "booking/index.html", context)

型

索引. html

{% extends "booking/layout.html" %}

{% block body %}

{% if user.is_authenticated %}

    <h2>INTERFACE</h2>

    <p>WEEK X < ></p>
    <br>

    <class class="card">
        <div class="card-header">
          BOOKINGS
        </div>
        <ul class="list-group list-group-flush">
            {% for session in sessions %}
                <li class="list-group-item">{{ session.day }}: <a href="{% url 'session' session.id %}">{{ session.program }} </a>
                    <form class="nav-item ms-auto float-end" action="{% url 'book' session.id %}" method="post">
                        {% csrf_token %}
{#                        {% for booking in bookings %}#}
                        {% for booking in session.booking_session %}
                            {% if booking.session == session %}
                                <button type="submit" class="btn btn-outline-light ms-auto btn-sm">quit</button>
                            {% else %}
                                <button type="submit" class="btn btn-outline-light ms-auto btn-sm">book</button>
                            {% endif %}
                        {% endfor %}
                    </form>
                </li>
            {% endfor %}
        </ul>
    </class>

{% endif %}

{% endblock %}

型
正如您所看到的，我在index.html示例中尝试了嵌套的for循环。我已经两次尝试接近我想要的结果（请参见index.html中的注解行），但都没有用。
我最初的方法是将所有会话作为一个变量生成（以显示所有会话），然后生成当前登录用户的预订列表（该列表显示哪些行的会话需要退出按钮，而不是预订按钮），这对我来说非常有意义。
不过，执行起来有些麻烦，还请帮忙。