19 lines
592 B
Python
19 lines
592 B
Python
from django.db.models import Q, F
|
|
from django.db import models
|
|
|
|
from apps.books.models import Book
|
|
from apps.shelves.models import Shelf
|
|
|
|
class ShelfItem(models.Model):
|
|
book = models.ForeignKey(Book, on_delete=models.CASCADE, related_name="shelf_items")
|
|
shelf = models.ForeignKey(Shelf, on_delete=models.CASCADE, related_name="book_items")
|
|
|
|
quantity = models.PositiveIntegerField(default=0)
|
|
|
|
class Meta:
|
|
constraints = [
|
|
models.UniqueConstraint(
|
|
fields=["book", "shelf"],
|
|
name="unique_book_per_shelf"
|
|
),
|
|
] |