Django:prefetch_related() 是否遵循反向关系查找? [英] Django: Does prefetch_related() follow reverse relationship lookup?
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问题描述
我已经在 django 1.4 中从主干尝试了 prefetch_related() 并且无法预取反向查找.
I've tried prefetch_related() in django 1.4 from trunk and can't make it to prefetch reverse lookup.
我的简化模型(每本书都有很多价格):
My simplified models (each book has many prices):
class Book(models.Model):
# some fields
class Price(models.Model):
book = models.ForeignKey(Book)
我的视图查询:
books = Book.objects.prefetch_related('price')
然后,我收到了 AttributeError 消息:
Then, I got the AttributeError message:
AttributeError: Cannot find 'price' on Book object, 'price' is an invalid parameter to prefetch_related()
如何让它工作?谢谢.
推荐答案
定义相关名称:
class Price(models.Model):
book = models.ForeignKey(Book, related_name='prices')
然后使用它:
books = Book.objects.prefetch_related('prices')
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