CODEWITHSUNDEEP
pythondjangodictionarydjango-queryset
Vaibhav
Vaibhav

Reputation: 1244

Update queryset with dictionary values

I am writing custom List filter and inside filter call i have a Django queryset as below

queryset =[qs1, qs2, qs3]

queryset have a attribute Count_val = 0, UUID = (unique id) for all objects in queryset

so lets say

qs1 = {uuid: 123, count_val: 0}

qs2 = {uuid: 456, count_val: 0}

qs1 = {uuid: 789, count_val: 0}

Also

I have a dictionary like {uuid: count_val}

example {123: 5, 456: 10 , 789: 15 }

I want to update queryset attribute count_values for all objects before returning queryset as response

Maybe annotate but how i pull each uuid for each value

queryset=queryset.annotate(count_val = Case(When(uuid_in=dictionary.keys(), then=dictionary[uuid]), field_type=Integer))   ## not correct syntax just an example
# inserting to new field is also fine
#queryset.extra(value={count_val : dictionary[uuid]})
return queryset

Thanks for help

Upvotes: 3

Views: 1417

Answers (2)

Iain Shelvington
Iain Shelvington

Reputation: 32294

You can create a list of When objects that match each key in the dictionary and return the value. Then unpack this list into positional arguments to the Case object

from django.db.models import Case, When, Value, IntegerField

whens = [When(uuid=k, then=Value(v)) for k, v in dictionary.items()]
queryset = queryset.annotate(count_val=Case(*whens, output_field=IntegerField(), default=Value(0)))

Upvotes: 5

Mohamed ElKalioby
Mohamed ElKalioby

Reputation: 2334

Let the query set be qs and dictionary be d

qs2=qs[:]
for elem in qs2:
    qs2["count_val"] = d[elem["uuid"]]
return qs2

Upvotes: 0

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