[Fixed]-Updating selection of objects, each with a different value in bulk (Django)

by

16👍

✅

Something like that:

from django.db.models import F
from django.db import transaction

with transaction.atomic():
    scores = {1: 1580, 4: 540, 2: 678}
    for user_id,score_to_add in scores:
        UserProfile.objects.filter(user_id=user_id).update(score=F('score')+score_to_add)

More on this here

You can take a look at this answer too.

[UPDATE]:

TL;DR: It’ll not make one db query but it will be faster cause each query lacks the database overhead.

As the docs and @ahmed in his answer say:

Django’s default behavior is to run in autocommit mode. Each query is
immediately committed to the database, unless a transaction is
active.

By using with transaction.atomic() all the inserts are grouped into a
single transaction. The time needed to commit the transaction is
amortized over all the enclosed insert statements and so the time per
insert statement is greatly reduced.

👤nik_m

0👍

transaction.atomic() proposed by @nik_m is good idea, but also you should get records from database in single request.

from django.db.models import F
from django.db import transaction

with transaction.atomic():
    scores = {1: 1580, 4: 540, 2: 678}
    users_to_update = UserProfile.objects.filter(
        user_id__in=scores.keys()
    ) 
    for user in users_to_update:
        user.update(score=F('score') + scores[user.user_id])
👤Ihor Pomaranskyy

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