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问题描述
我有以下内容:
class Product(models.Model): name = models.CharField(max_length=255) class Action(models.Model): product = models.ForeignKey(Product) created_at = models.DateTimeField(auto_now_add=True)我想检索由created_at DESC订购的10个最新动作,包含不同的产品。
I would like to retrieve the 10 most recent actions ordered by created_at DESC with distinct products.
以下是接近结果但仍然错过了排序:
The following is close to the result but still misses the ordering:
Action.objects.all().order_by('product_id').distinct('product_id')[:10]推荐答案
您的解决方案似乎正在尝试做太多事情。它还将导致2个单独的SQL查询。这可以正常工作,只需一个查询:
Your solution seems like it's trying to do too much. It will also result in 2 separate SQL queries. This would work fine and with only a single query:
action_ids = Action.objects.order_by('product_id', '-created_at')\ .distinct('product_id').values_list('id', flat=True) result = Action.objects.filter(id__in=action_ids)\ .order_by('-created_at')[:10]更多推荐
Django查询与order
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