I have a Django application that reads data from a web API and puts it in a database.
Is there a way to create a new object from a mode but prevent the duplicate exception if the object already exists?
In other words, is there a way to save an object, but to just do nothing if it already exists?
4 Answers
In Django 1.7, you can also do:
It can be achieved using Model.objects.get_or_create()
Example
obj, created = Person.objects.get_or_create(
first_name='John',
last_name='Lennon',
defaults={'birthday': date(1940, 10, 9)},
)
Any keyword arguments(here first_name and last_name) passed to get_or_create() — except an optional one called defaults — will be used to query in database(find the object) in database.
It returns a tuple, if an object is found, get_or_create() returns a tuple of that object and False.
Note: Same thing can also be achieved using try except statements
Example:
try:
obj = Person.objects.get(first_name='John', last_name='Lennon')
except Person.DoesNotExist:
obj = Person(first_name='John', last_name='Lennon', birthday=date(1940, 10, 9))
obj.save()
Looks like in newer versions of Django the save() function does an UPDATE or INSERT by default. See here.
