Django: get the first object from a filter query or create

Question

In Django, queryset provides a method called get_or_create that either returns an objects or creates an object.

However, like the get method, get_or_create can throw an exception if the query returns multiple objects.

Is there an method to do this elegantly:

objects = Model.manager.filter(params) if len(objects) == 0:    obj = Model.objects.create(params) else:    obj = objects[0] 

Answer 1

get_or_create() is just a convenience function so there's nothing wrong with writing your own, like pavid has shown or

result = Model.objects.filter(field__lookup=value)[0] if not result:    result = Model.objects.create(...) return result 

EDIT As suggested, changed the [:1] slice (which returns a single-entry list) after the filter to [0] (which returns the actual object). The problem with this is it will raise an exception if there is not match to the query.

This will also raise a simliar exception:

Model.objects.filter(field_lookup=value).latest() 

Looking at the question again, I'm not sure whether the original poster is looking to return multiple objects/rows, or just a way to get around raising an exception when retrieving a single object/row.

Here's another option?

results = Model.objects.filter(...) if results.exists():     return results else:     return Model.objects.create(...) 

and another:

result = None try:     result = Model.objects.get(...) except Model.DoesNotExist:     result = Model.objects.create(...) 

There's nothing wrong with raising & catching exceptions!

Answer 2

From django 1.6 there is a convenience method first() that returns the first result in a filter query, or None.

obj = Model.manager.filter(params).first() if obj is None:     obj = Model.objects.create(params)