Question

I am trying to make a search view in Django. It is a search form with freetext input + some options to select, so that you can filter on years and so on. This is some of the code I have in the view so far, the part that does the filtering. And I would like some input on how expensive this would be on the database server.

soknad_list = Soknad.objects.all()

if var1:     soknad_list = soknad_list.filter(pub_date__year=var1)  if var2:     soknad_list = soknad_list.filter(muncipality__name__exact=var2)  if var3:     soknad_list = soknad_list.filter(genre__name__exact=var3)  # TEXT SEARCH stop_word_list = re.compile(STOP_WORDS, re.IGNORECASE) search_term = '%s' % request.GET['q'] cleaned_search_term = stop_word_list.sub('', search_term) cleaned_search_term = cleaned_search_term.strip() if len(cleaned_search_term) != 0:     soknad_list = soknad_list.filter(Q(dream__icontains=cleaned_search_term) | Q(tags__icontains=cleaned_search_term) | Q(name__icontains=cleaned_search_term) | Q(school__name__icontains=cleaned_search_term)) 

So what I do is, first make a list of all objects, then I check which variables exists (I fetch these with GET on an earlier point) and then I filter the results if they exists. But this doesn’t seem too elegant, it probably does a lot of queries to achieve the result, so is there a better way to this?

It does exactly what I want, but I guess there is a better/smarter way to do this. Any ideas?

Answer 1

filter itself doesn’t execute a query, no query is executed until you explicitly fetch items from query (e.g. get), and list( query ) also executes it.