How to update existing data and create new one django base command? - django

Question

i am trying to store data in from json file and i added its not a problem to add data but when i trigger data again again they copy data and create same new one that i don't want , i want that it will update existing data and if there will new data in json file it will add in model .
here is my django base command code.
from django.core.management.base import BaseCommand
import requests
from demo.models import CoronaAge, CoronaSex, CoronaComorbidity
class Command(BaseCommand):
def handle(self, *args, **kwargs):
url = 'https://api.the2019ncov.com/api/fatality-rate'
r = requests.get(url)
titles = r.json()
print(titles)
# For between age
for title in titles['byAge'] or []:
CoronaAge.objects.update_or_create(
age=title['age'],
rate=title['rate']
)
context = {'titles': CoronaAge.objects.all()}
# for sex wise male and female
for title in titles['bySex'] or []:
CoronaSex.objects.update_or_create(
sex=title['sex'],
rate=title['rate']
)
context = {'titles': CoronaSex.objects.all()}
for title in titles['byComorbidity'] or []:
CoronaComorbidity.objects.update_or_create(
condition=title['preExistingCondition'],
rate=title['rate']
)
context = {'titles': CoronaComorbidity.objects.all()}

Answer 1

This is how I would solve it. Get a list existing data. Then, for each new entry check if it exists in the db, create new object, add to list and at the end run bulk_create to insert all of them in one hit. If exists, then update all fields that you want and again, run bulk update at the end.
corona_ages = CoronaAge.objects.all()
new_ages = []
existing_ages = []
for title in titles['byAge'] or []:
entry = corona_ages.filter(age=title['age']).first():
if not entry:
new_data = CoronaAge(**title)
new_ages.append(new_data)
else:
entry['some_param'] = title['some_param']
entry['other_param'] = title['other_param']
existing_ages.append(new_date)
CoronaAge.objects.bulk_create(new_ages)
CoronaAge.objects.bulk_update(existing_ages)