Model 链接到另外两个模型。 如何访问 django 中其他两个模型的属性

Question

I am in a process of creating a Room Booking Management System using Django. I have faced an issue in accessing models.

Here is my Room Model

class Room(models.Model):
name = models.CharField(max_length=30)
date =  models.DateField()
defined_check_in_time =  models.IntegerField()
defined_check_out_time = models.IntegerField()
booked = models.BooleanField(default = False)

USERNAME_FIELD = 'name'

class Meta:
    ordering = ['date', 'defined_check_in_time']

def __str__(self):
    return self.name

def is_booked(self):
    return self.booked

def set_booked(self):
    self.booked = True

Here is my Booking Model

class Booking(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
room = models.ForeignKey(Room, on_delete=models.CASCADE)

def __str__(self):
    return f'{self.user} has booked {self.room} from {self.room.defined_check_in_time} to {self.room.defined_check_out_time} on {self.room.date}'

I have linked the User model and Room model in the Booking model using a foreign key when a user books a room. User model is defined in another file. I have not included that model code here.

When a user books a room, the corresponding room object and user object is linked to the booking object. To display the bookings of the user, I need to query the Booking model using a User object.

Here, my question is how i can access user and room object attributes inside the booking object?

Answer 1

To access information within your booking object, you must first select a booking object, whichever way you choose to identify a booking.. maybe by an id. Let's say booking id=100

booking = Booking.objects.get(id=100)

Now to find foreign key info you can just. lookup.

booking_user = booking.user.username booking_room = booking.room.name

or to find any bookings on rooms booked:

booked_rooms = Booking.objects.filter(room.booked == True)