python - How to organize a trigram search so that by searching for a relation many-to-many, we get an object that is associated with it in the singular?

Question

I have addresses/models.py:

class Street(models.Model):
    ...
    town = models.ForeignKey(Town, default=None, related_name='streets', on_delete=models.CASCADE, verbose_name='')
    name = models.CharField(max_length=200, db_index=True, verbose_name='',
                            help_text='')
    slug = models.SlugField(max_length=200, db_index=True, verbose_name='')
    is_active = models.BooleanField(default=True, verbose_name='')
    ...

And providers/models.py:

class Provider(models.Model):
    ...
    location = models.ManyToManyField(Street, db_index=True, symmetrical=False, related_name='providers',
                                      verbose_name='')
    name = models.CharField(max_length=200, db_index=True, verbose_name='')
    slug = models.SlugField(max_length=200, db_index=True, verbose_name='')
    is_active = models.BooleanField(default=True, verbose_name='')
    ...

And home/views.py:

def home(request):

    ...
    form = SearchForm()
    query = None
    results = []
    if 'query' in request.GET:
        form = SearchForm(request.GET)
        if form.is_valid():
            query = form.cleaned_data['query']
    
            results = Provider.objects.annotate(
                similarity=TrigramSimilarity('location__name', query),
            ).filter(similarity__gt=0.35).order_by('-similarity')
    
            context = {
                'form': form,
                'query': query,
                'results': results,
            }
    
            return render(request, 'home/home.html', context)
        else:
            return render(request, 'home/search_error.html')
    
    context = {
        'form': form,
        'query': query,
        'results': results,
    }
    
    return render(request, 'home/home.html', context)

At the front home/home.html:

<!-- provider items in results -->
{% for p in results %}
    |it's just here html|
{% endfor %}

As a result (I enter the street name and it finds the correct answer for me, but only lists it as many times as it is mentioned in the request):

I want to make it like this:

question from:https://stackoverflow.com/questions/65844377/how-to-organize-a-trigram-search-so-that-by-searching-for-a-relation-many-to-man

Answer 1

When using postgres in a method call, you can enumerate field names whose values determine the uniqueness of records. If no parameters are specified, then the uniqueness of each record will be determined by the values of all its fields. To display a unique record, use the method distinct():

results = Provider.objects.annotate(
                similarity=TrigramSimilarity('location__name', query),
            ).filter(similarity__gt=0.85).distinct().order_by('-similarity')