Django .values().distinct() returns a lot more records than .values().distinct().count()

[James Lin]

I have a table virtualmachineresources, which has 100k+ rows, it has columns machine and cluster, some rows the cluster field is empty. it has repeating rows of machine + with/without cluster, hence I want to use the distinct() method.

using .values().distinct().count(), it returned 2k rows

In [6]: VirtualMachineResources.objects.all().values('machine', 'cluster')
   ...: .distinct().count()                                               
Out[6]: 2247

When I loop through the distinct query

for resource in VirtualMachineResources.objects.all().values('machine', 'cluster').distinct(): 
    print(resource['machine'], resource['cluster'])

I observed it returned 100k rows, with repeating rows that the same 'machine` with/without the cluster.

Here is the corresponding stackoverflow question ​https://stackoverflow.com/questions/54354462/django-distinct-returns-more-records-than-count