python - Get one related object in single request for Django ORM -

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i have models

class book(models.model):     title = models.charfield(max_length=255, blank=false, null=false)  class like(models.model):     user = models.foreignkey(user, related_name="like_user", blank=false, null=false)     book = models.foreignkey(book, related_name="like_book", blank=false, null=false)     class meta:         unique_together = ["user", "book"]

i want books , check if current user liked each book in single request

book.objects.select_related('like_book').all()

won't work because of many results

book.objects.prefetch_related('like_book').all()

will cache like_set contain likes book. not 1 user.

in end want have additional field is_liked

books = book.objects.magic_fetch('like_book', user=self.request.user).all() books[0].is_liked

* updated address comments *

so speaking, think use:

book.objects.annotate(is_liked=case(when(like__user=self.request.user, then=true), default=false))

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