[Django]-Is there an elegant way to model and represent a one to many inside a many to many relationship on Django?

Whenever you think you have to do multiple descending loops like you have, think about whether or not you can approach the problem from the opposite end.

As @Pathetique pointed out, the following link shows how to minimise the number of queries you’re performing:

https://docs.djangoproject.com/en/1.5/topics/db/optimization/#retrieve-everything-at-once-if-you-know-you-will-need-it

The highlight in that link is select_related which only works on ForeignKeys, and prefetch_related which only works on ManyToManyFields.

Since you were approaching this problem from the point of view of “I have a set of teams, now I want to show all the data associated with those teams”, you are unable to use any of the optimisations available since Team does not have ForeignKeys or ManyToManyFields.

Instead, you can approach the problem like so “I want to show all Milestones, grouped by team and then by quality streams”. Since your Milestone class has access to all the data you require, it makes the queryset very easy to construct, only generating a single query.

def my_view(request):
    queryset = Milestone.objects.select_related(
        'team', 'quality_stream'
    ).order_by(
        'team__name', 'quality_stream__name'
    ) # a single query to fetch all teams + streams + milestones

    return render_to_response('/your/template.html', 
        { 'milestones':queryset },
        context_instance=RequestContext(request)
    )

Now, your template is going to break the way you have it constructed. This is where the definition of the problem I mentioned before comes in. You have all your milestones, but you want to group them by team and then by quality stream. The ordering of our queryset helps us now, since we can iterate through all the milestones, and check whether we’re up to a new team or a new quality stream.

# your template
{% for milestone in milestones %}
    {% ifchanged %} <p> {{ milestone.team.name }} </p> {% endifchanged %}
    {% ifchanged %} <p> {{ milestone.quality_stream.name }} </p> {% endifchanged %}
    <p> {{ milestone.name }} </p>
{% endfor %}

The above template uses the ifchanged template tags, which seems designed exactly for this purpose.