CODEWITHSUNDEEP
pythondjango
iraj jelodari
iraj jelodari

Reputation: 3366

Why does Q object return duplicated results?

I have a ViewSet that has a get_queryset method. This method filters objects using a Q object:

def get_queryset(self):
    request = self.request
    query = Ticket.objects.filter(
                            Q(message_type__users__in=[request.user])|
                            Q(reference__to_user=request.user)
                            )
    return query

output:

[<Ticket: 24>, <Ticket: 24>, <Ticket: 24>, <Ticket: 24>]

it returns the same Ticket (id = 24) four times. For 'GET' requests from client, i get MultipleObjectsReturned exception:

get() returned more than one Ticket -- it returned 4!

Why does Q object return multiple results?

Upvotes: 2

Views: 660

Answers (2)

Martin B.
Martin B.

Reputation: 1928

Indeed, the way SQL works, it means you have 1 ticket, but either 4 message_type or 4 reference objects related to that ticket, so when you JOIN, all of them will be returned.

Using .distinct() should solve your problems.

Upvotes: 3

kungphu
kungphu

Reputation: 4859

This filters down to SQL: The way a query is built can result in the same row either satisfying more than one condition or satisfying the same condition more than once.

If this is the best way to format your query, try tacking on .distinct() to avoid duplicate results.

Upvotes: 1

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