查询数据库并根据数据库中的内容删除 Charfield Choices

Question

我使用 Django forms 创建了一个预订表格。为了选择时间，我有一系列的选择。 但是，我只想在该数据和时间不存在的情况下在表单中显示这些选项。

这是我的模型.py：

from django.db import models
from django.contrib.auth.models import User
from django.core import validators
import datetime

TIME_CHOICES = (
        ('12:00:00', '12pm'),
        ('12:15:00', '12:15pm'),
        ('12:30:00', '12:30pm'),
        ('12:45:00', '12:45pm'),
        ('13:00:00', '1pm'),
        ('13:15:00', '1:15pm'),
        ('13:30:00', '1:30pm'),
        ('13:45:00', '1:45pm'),
        ('14:00:00', '2pm'),
        ('14:15:00', '2:15pm'),
        ('14:30:00', '2:30pm'),
        ('14:45:00', '2:45pm'),
        ('15:00:00', '3pm'),
        ('15:15:00', '3:15pm'),
        ('15:30:00', '3:30pm'),
        ('15:45:00', '3:45pm'),
        ('16:00:00', '4pm'),
        ('16:15:00', '4:15pm'),
        ('16:30:00', '4:30pm'),
        ('16:45:00', '4:45pm'),
        ('17:00:00', '5pm'),
        ('17:15:00', '5:15pm'),
        ('17:30:00', '5:30pm'),
        ('17:45:00', '5:45pm'),
        ('18:00:00', '6pm'),
        ('18:15:00', '6:15pm'),
        ('18:30:00', '6:30pm'),
        ('18:45:00', '6:45pm'),
        ('19:00:00', '7pm'),
        ('19:15:00', '7:15pm'),
        ('19:30:00', '7:30pm'),
        ('19:45:00', '7:45pm'),
        ('20:00:00', '8pm'),
        ('20:15:00', '8:15pm'),
        ('20:30:00', '8:30pm'),
        ('20:45:00', '8:45pm'),
        ('21:00:00', '9pm'),
        ('21:15:00', '9:15pm'),
        ('21:30:00', '9:30pm'),
        ('21:45:00', '9:45pm'),
        ('22:00:00', '10pm'),
        ('22:15:00', '10:15pm'),
        ('22:30:00', '10:30pm'),
        ('22:45:00', '10:45pm'),
    )


class Booking(models.Model):
    user = models.ForeignKey(
        User, on_delete=models.CASCADE, null=True, blank=True
        )
    first_name = models.CharField(max_length=25, null=False, blank=False)
    last_name = models.CharField(max_length=25, null=False, blank=False)
    email_address = models.EmailField(default="email@email.com")
    phone_number = models.IntegerField()
    date_of_booking = models.DateField(default=datetime.date.today())
    time_of_booking = models.CharField(
        max_length=10, choices=TIME_CHOICES, default=""
        )
    number_of_people = models.IntegerField()
    special_requests = models.CharField(max_length=200)

    def __str__(self):  # code adapted from Models Part 2 FST walkthrough
        return self.first_name + " " + self.last_name + " | " \
             + str(self.date_of_booking) + " at " + str(self.time_of_booking)

这是我的 views.py 函数：

def make_booking(request):

    if request.method == 'POST':
        form = BookingForm(request.POST)
        if form.is_valid():
            form.save()
            print('form saved')
            return redirect(get_bookings)
        else:
            print('broken')
   
    form = BookingForm()
    context = {
        'form': form
        }
    return render(request, 'booking/make_booking.html', context)

如何编写 function 以从下拉列表中删除已提交到数据库的日期/时间。

在此处输入图像描述

我只能找到告诉我如何记录当前 session 而不是如何查询数据库的信息。

Answer 1

为什么不创建时间选择 model 而不是将其硬编码在 models.py 上。 然后你可以使用类似的东西：

TimeModel.objects.filter(time=form.time_of_booking).delete()