Ordering a Django queryset based on other list with ids and scores

问题

I'm a bit mentally stuck at something, that seems really simple at first glance.

I'm grabbing a list of ids to be selected and scores to sort them based on.

My current solution is the following:

ids = [1, 2, 3, 4, 5]

items = Item.objects.filter(pk__in=ids)

Now I need to add a score based ordering somehow so I'll build the following list:

scores = [
        {'id': 1, 'score': 15},
        {'id': 2, 'score': 7},
        {'id': 3, 'score': 17},
        {'id': 4, 'score': 11},
        {'id': 5, 'score': 9},
    ]

ids = [score['id'] for score in scores]

items = Item.objects.filter(pk__in=ids)

So far so good - but how do I actually add the scores as some sort of aggregate and sort the queryset based on them?

回答1:

Sort the scores list, and fetch the queryset using in_bulk().

scores = [
    {'id': 1, 'score': 15},
    {'id': 2, 'score': 7},
    {'id': 3, 'score': 17},
    {'id': 4, 'score': 11},
    {'id': 5, 'score': 9},
]
sorted_scores = sorted(scores)  # use reverse=True for descending order
ids = [score['id'] for score in scores]
items = Item.objects.in_bulk(ids)

Then generate a list of the items in the order you want:

items_in_order = [items[x] for x in ids]

来源：https://stackoverflow.com/questions/45693437/ordering-a-django-queryset-based-on-other-list-with-ids-and-scores