Django过滤器检查给定日期之间是否还有其他预订
Ben*_*Max 8 django django-models django-views django-rest-framework
我正在尝试制作酒店预订应用程序。所以我有两个模型，即房间和预订。
# models
class Room(models.Model):
name = models.CharField(max_length=50)
class Booking(models.Model):
room = models.ForeignKey(Room, on_delete=models.CASCADE)
booked_for_datetime = models.DateTimeField()
booked_till_datetime = models.DateTimeField()
当所需房间已经有另一个预订时，我想通知房间是否不可用，或者如果它确实可用，则创建一个预订。
我正在使用 django rest 框架，所以我必须在 create 和 update 方法上应用这些验证，可能是这样的：
# serializers
def roomAvailable(validated_data):
available = False
# ...
# validation check here...
# ...
return available
class BookingSerializer(serializers.ModelSerializer):
class Meta:
model = Booking
fields = '__all__'
def create(self, validated_data):
if roomAvailable(validated_data):
return Booking.objects.create(**validated_data)
else:
raise serializers.ValidationError({
"detail": "Room is not available for these dates."
})
def update(self, instance, validated_data):
if roomAvailable(validated_data):
...
instance.save()
else:
raise serializers.ValidationError({
"detail": "Room is not available for these dates."
})
return instance
例如：
101 房间已在 01-12-2019 至 04-12-2019 之间预订。
如果有人试图预订同一个房间，我想阻止预订 (101)
- 29-11-2019 至 01-12-2019
- 29-11-2019 至 02-12-2010
- 30-11-2019 至 05-12-2019
- 01-12-2019 至 04-12-2019
- 02-12-2019 至 03-12-2019
- 04-12-2019 至 07-12-2019
现在这就是我的过滤方式，但我不确定这是否是最好的方法，因为我可能会错过其他会导致重复预订的预订，也许还有另一种方法可以解决这个问题？
def roomAvailable(validated_data):
available = True
...
if room.booking_set.filter(
Q(booked_till_datetime__date__gte=validated_data['booked_for_datetime'],
booked_till_datetime__date__lte=validated_data['booked_till_datetime']) |
Q(booked_for_datetime__date__gte=validated_data['booked_for_datetime'],
booked_for_datetime__date__lte=validated_data['booked_till_datetime']) |
Q(booked_for_datetime__date__gte=validated_data['booked_for_datetime'],
booked_till_datetime__date__lte=validated_data['booked_till_datetime']) |
Q(booked_for_datetime__date__lte=validated_data['booked_for_datetime'],
booked_till_datetime__date__gte=validated_data['booked_till_datetime'])
).exists():
available = False
return available
你能帮我如何检查新日期之间是否有任何预订吗？
Short answer
start_date = '2019-11-29'
end_date = '2019-12-01'
filter_params = dict(booked_for_datetime__date__lte=end_date, booked_till_datetime__date__gte=start_date) # just for redability
is_occupied = Booking.objects.filter(**filter_params, room__name=101).exists()
Notes:
1. is_occupied will be a boolean
2. I have used the date filter, since OP provided only date, not a datetime
Explanation
Someone booked the room (101) between 01-12-2019 and 06-12-2019, which is marked in Red. According to the conditions given in the OP, the available slots are marked in Green.
Logic
- input "end time" should be less than available
booked_for_datetime__date - input "start time" should be greater than available
booked_till_datetime__date
Shell output
In [2]: date_list = [
...: dict(start='2019-11-29', end='2019-12-01'),
...: dict(start='2019-11-29', end='2019-12-02'),
...: dict(start='2019-11-30', end='2019-12-05'),
...: dict(start='2019-12-01', end='2019-12-04'),
...: dict(start='2019-12-02', end='2019-12-03'),
...: dict(start='2019-12-02', end='2019-12-04'),
...: dict(start='2019-12-03', end='2019-12-04'),
...: dict(start='2019-12-02', end='2019-12-05'),
...: dict(start='2019-12-04', end='2019-12-06'),
...: dict(start='2019-12-04', end='2019-12-07'),
...: dict(start='2019-12-06', end='2019-12-07'),
...: dict(start='2019-12-07', end='2019-12-10'),
...: dict(start='2019-11-29', end='2019-11-30'),
...: ]
In [3]:
In [3]: Booking.objects.all()
Out[3]: <QuerySet [<Booking: Booking object (1)>]>
In [4]: Booking.objects.all()[0].__dict__
Out[4]:
{'_state': <django.db.models.base.ModelState at 0x7efee64d5a58>,
'id': 1,
'room_id': 1,
'booked_for_datetime': datetime.datetime(2019, 12, 1, 2, 45, 9, tzinfo=<UTC>),
'booked_till_datetime': datetime.datetime(2019, 12, 5, 2, 45, 8, tzinfo=<UTC>)}
In [5]: # booked the room from 01-12-2019 to 05-12-2019
In [6]: for date in date_list:
...: start_date, end_date = date.values()
...: filter_params = dict(booked_for_datetime__date__lte=end_date, booked_till_datetime__date__gte=start_date)
...: is_occupied = Booking.objects.filter(**filter_params, room__name=101).exists()
...: if is_occupied:
...: print('Not Available on this range, start: {} end: {}'.format(start_date, end_date))
...: else:
...: print('Available on this range, start: {} end: {}'.format(start_date, end_date))
...:
Not Available on this range, start: 2019-11-29 end: 2019-12-01
Not Available on this range, start: 2019-11-29 end: 2019-12-02
Not Available on this range, start: 2019-11-30 end: 2019-12-05
Not Available on this range, start: 2019-12-01 end: 2019-12-04
Not Available on this range, start: 2019-12-02 end: 2019-12-03
Not Available on this range, start: 2019-12-02 end: 2019-12-04
Not Available on this range, start: 2019-12-03 end: 2019-12-04
Not Available on this range, start: 2019-12-02 end: 2019-12-05
Not Available on this range, start: 2019-12-04 end: 2019-12-06
Not Available on this range, start: 2019-12-04 end: 2019-12-07
Available on this range, start: 2019-12-06 end: 2019-12-07
Available on this range, start: 2019-12-07 end: 2019-12-10
Available on this range, start: 2019-11-29 end: 2019-11-30
Mas*_*sta -1
首先我建议使用DateField而不是DateTimeField; 如果您使用 PostgreSQL 作为数据库，您也可以使用DateRangeField。
这个查询集或多或少是你需要的
qs = Room.objects.exclude(
booking__booked_for_datetime__lte=validated_data,
booking__booked_till_datetime__gte=validated_data
)
如果您需要“只是”知道是否有可用房间，您可以这样做
qs.Exists()
和
qs.values('id', 'name')
您将获得所有可用房间的id和name